@misc{14842, abstract = {Eva Benkova received a PhD in Biophysics at the Institute of Biophysics of the Czech Academy of Sciences in 1998. After working as a postdoc at the Max Planck Institute in Cologne and the Center for Plant Molecular Biology (ZMBP) in Tübingen, she became a group leader at the Plant Systems Biology Department of the Vlaams Instituut voor Biotechnologie (VIB) in Gent. In 2012, she transitioned to an Assistant Professor position at the Institute of Science and Technology Austria (ISTA) where she was later promoted to Professor. Since 2021, she has served as the Dean of the ISTA Graduate School. As a plant developmental biologist, she focuses on unraveling the molecular mechanisms and principles that underlie hormonal interactions in plants. In her current work, she explores the intricate connections between hormones and regulatory pathways that mediate the perception of environmental stimuli, including abiotic stress and nitrate availability.}, author = {Benková, Eva}, booktitle = {Current Biology}, issn = {1879-0445}, number = {1}, pages = {R3--R5}, publisher = {Elsevier}, title = {{Eva Benkova}}, doi = {10.1016/j.cub.2023.11.039}, volume = {34}, year = {2024}, } @article{14082, abstract = {Epithelial barrier function is commonly analyzed using transepithelial electrical resistance, which measures ion flux across a monolayer, or by adding traceable macromolecules and monitoring their passage across the monolayer. Although these methods measure changes in global barrier function, they lack the sensitivity needed to detect local or transient barrier breaches, and they do not reveal the location of barrier leaks. Therefore, we previously developed a method that we named the zinc-based ultrasensitive microscopic barrier assay (ZnUMBA), which overcomes these limitations, allowing for detection of local tight junction leaks with high spatiotemporal resolution. Here, we present expanded applications for ZnUMBA. ZnUMBA can be used in Xenopus embryos to measure the dynamics of barrier restoration and actin accumulation following laser injury. ZnUMBA can also be effectively utilized in developing zebrafish embryos as well as cultured monolayers of Madin–Darby canine kidney (MDCK) II epithelial cells. ZnUMBA is a powerful and flexible method that, with minimal optimization, can be applied to multiple systems to measure dynamic changes in barrier function with spatiotemporal precision.}, author = {Higashi, Tomohito and Stephenson, Rachel E. and Schwayer, Cornelia and Huljev, Karla and Higashi, Atsuko Y. and Heisenberg, Carl-Philipp J and Chiba, Hideki and Miller, Ann L.}, issn = {1477-9137}, journal = {Journal of Cell Science}, number = {15}, publisher = {The Company of Biologists}, title = {{ZnUMBA - a live imaging method to detect local barrier breaches}}, doi = {10.1242/jcs.260668}, volume = {136}, year = {2023}, } @article{13214, abstract = {Nitrogen is an important macronutrient required for plant growth and development, thus directly impacting agricultural productivity. In recent years, numerous studies have shown that nitrogen-driven growth depends on pathways that control nitrate/nitrogen homeostasis and hormonal networks that act both locally and systemically to coordinate growth and development of plant organs. In this review, we will focus on recent advances in understanding the role of the plant hormones auxin and cytokinin and their crosstalk in nitrate-regulated growth and discuss the significance of novel findings and possible missing links.}, author = {Abualia, R and Riegler, Stefan and Benková, Eva}, issn = {2073-4409}, journal = {Cells}, number = {12}, publisher = {MDPI}, title = {{Nitrate, auxin and cytokinin - a trio to tango}}, doi = {10.3390/cells12121613}, volume = {12}, year = {2023}, } @article{11734, abstract = {Mineral nutrition is one of the key environmental factors determining plant development and growth. Nitrate is the major form of macronutrient nitrogen that plants take up from the soil. Fluctuating availability or deficiency of this element severely limits plant growth and negatively affects crop production in the agricultural system. To cope with the heterogeneity of nitrate distribution in soil, plants evolved a complex regulatory mechanism that allows rapid adjustment of physiological and developmental processes to the status of this nutrient. The root, as a major exploitation organ that controls the uptake of nitrate to the plant body, acts as a regulatory hub that, according to nitrate availability, coordinates the growth and development of other plant organs. Here, we identified a regulatory framework, where cytokinin response factors (CRFs) play a central role as a molecular readout of the nitrate status in roots to guide shoot adaptive developmental response. We show that nitrate-driven activation of NLP7, a master regulator of nitrate response in plants, fine tunes biosynthesis of cytokinin in roots and its translocation to shoots where it enhances expression of CRFs. CRFs, through direct transcriptional regulation of PIN auxin transporters, promote the flow of auxin and thereby stimulate the development of shoot organs.}, author = {Abualia, Rashed and Ötvös, Krisztina and Novák, Ondřej and Bouguyon, Eleonore and Domanegg, Kevin and Krapp, Anne and Nacry, Philip and Gojon, Alain and Lacombe, Benoit and Benková, Eva}, issn = {1091-6490}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {31}, publisher = {Proceedings of the National Academy of Sciences}, title = {{Molecular framework integrating nitrate sensing in root and auxin-guided shoot adaptive responses}}, doi = {10.1073/pnas.2122460119}, volume = {119}, year = {2022}, } @article{12291, abstract = {The phytohormone auxin triggers transcriptional reprogramming through a well-characterized perception machinery in the nucleus. By contrast, mechanisms that underlie fast effects of auxin, such as the regulation of ion fluxes, rapid phosphorylation of proteins or auxin feedback on its transport, remain unclear1,2,3. Whether auxin-binding protein 1 (ABP1) is an auxin receptor has been a source of debate for decades1,4. Here we show that a fraction of Arabidopsis thaliana ABP1 is secreted and binds auxin specifically at an acidic pH that is typical of the apoplast. ABP1 and its plasma-membrane-localized partner, transmembrane kinase 1 (TMK1), are required for the auxin-induced ultrafast global phospho-response and for downstream processes that include the activation of H+-ATPase and accelerated cytoplasmic streaming. abp1 and tmk mutants cannot establish auxin-transporting channels and show defective auxin-induced vasculature formation and regeneration. An ABP1(M2X) variant that lacks the capacity to bind auxin is unable to complement these defects in abp1 mutants. These data indicate that ABP1 is the auxin receptor for TMK1-based cell-surface signalling, which mediates the global phospho-response and auxin canalization.}, author = {Friml, Jiří and Gallei, Michelle C and Gelová, Zuzana and Johnson, Alexander J and Mazur, Ewa and Monzer, Aline and Rodriguez Solovey, Lesia and Roosjen, Mark and Verstraeten, Inge and Živanović, Branka D. and Zou, Minxia and Fiedler, Lukas and Giannini, Caterina and Grones, Peter and Hrtyan, Mónika and Kaufmann, Walter and Kuhn, Andre and Narasimhan, Madhumitha and Randuch, Marek and Rýdza, Nikola and Takahashi, Koji and Tan, Shutang and Teplova, Anastasiia and Kinoshita, Toshinori and Weijers, Dolf and Rakusová, Hana}, issn = {1476-4687}, journal = {Nature}, number = {7927}, pages = {575--581}, publisher = {Springer Nature}, title = {{ABP1–TMK auxin perception for global phosphorylation and auxin canalization}}, doi = {10.1038/s41586-022-05187-x}, volume = {609}, year = {2022}, } @phdthesis{11879, abstract = {As the overall global mean surface temperature is increasing due to climate change, plant adaptation to those stressful conditions is of utmost importance for their survival. Plants are sessile organisms, thus to compensate for their lack of mobility, they evolved a variety of mechanisms enabling them to flexibly adjust their physiological, growth and developmental processes to fluctuating temperatures and to survive in harsh environments. While these unique adaptation abilities provide an important evolutionary advantage, overall modulation of plant growth and developmental program due to non-optimal temperature negatively affects biomass production, crop productivity or sensitivity to pathogens. Thus, understanding molecular processes underlying plant adaptation to increased temperature can provide important resources for breeding strategies to ensure sufficient agricultural food production. An increase in ambient temperature by a few degrees leads to profound changes in organ growth including enhanced hypocotyl elongation, expansion of petioles, hyponastic growth of leaves and cotyledons, collectively named thermomorphogenesis (Casal & Balasubramanian, 2019). Auxin, one of the best-studied growth hormones, plays an essential role in this process by direct activation of transcriptional and non-transcriptional processes resulting in elongation growth (Majda & Robert, 2018).To modulate hypocotyl growth in response to high ambient temperature (hAT), auxin needs to be redistributed accordingly. PINs, auxin efflux transporters, are key components of the polar auxin transport (PAT) machinery, which controls the amount and direction of auxin translocated in the plant tissues and organs(Adamowski & Friml, 2015). Hence, PIN-mediated transport is tightly linked with thermo-morphogenesis, and interference with PAT through either chemical or genetic means dramatically affecting the adaptive responses to hAT. Intriguingly, despite the key role of PIN mediated transport in growth response to hAT, whether and how PINs at the level of expression adapt to fluctuation in temperature is scarcely understood. With genetic, molecular and advanced bio-imaging approaches, we demonstrate the role of PIN auxin transporters in the regulation of hypocotyl growth in response to hAT. We show that via adjustment of PIN3, PIN4 and PIN7 expression in cotyledons and hypocotyls, auxin distribution is modulated thereby determining elongation pattern of epidermal cells at hAT. Furthermore, we identified three Zinc-Finger (ZF) transcription factors as novel molecular components of the thermo-regulatory network, which through negative regulation of PIN transcription adjust the transport of auxin at hAT. Our results suggest that the ZF-PIN module might be a part of the negative feedback loop attenuating the activity of the thermo-sensing pathway to restrain exaggerated growth and developmental responses to hAT.}, author = {Artner, Christina}, isbn = {978-3-99078-022-0}, issn = {2663-337X}, keywords = {high ambient temperature, auxin, PINs, Zinc-Finger proteins, thermomorphogenesis, stress}, pages = {128}, publisher = {Institute of Science and Technology Austria}, title = {{Modulation of auxin transport via ZF proteins adjust plant response to high ambient temperature}}, doi = {10.15479/at:ista:11879}, year = {2022}, } @article{8582, abstract = {Cell and tissue polarization is fundamental for plant growth and morphogenesis. The polar, cellular localization of Arabidopsis PIN‐FORMED (PIN) proteins is crucial for their function in directional auxin transport. The clustering of PIN polar cargoes within the plasma membrane has been proposed to be important for the maintenance of their polar distribution. However, the more detailed features of PIN clusters and the cellular requirements of cargo clustering remain unclear. Here, we characterized PIN clusters in detail by means of multiple advanced microscopy and quantification methods, such as 3D quantitative imaging or freeze‐fracture replica labeling. The size and aggregation types of PIN clusters were determined by electron microscopy at the nanometer level at different polar domains and at different developmental stages, revealing a strong preference for clustering at the polar domains. Pharmacological and genetic studies revealed that PIN clusters depend on phosphoinositol pathways, cytoskeletal structures and specific cell‐wall components as well as connections between the cell wall and the plasma membrane. This study identifies the role of different cellular processes and structures in polar cargo clustering and provides initial mechanistic insight into the maintenance of polarity in plants and other systems.}, author = {Li, Hongjiang and von Wangenheim, Daniel and Zhang, Xixi and Tan, Shutang and Darwish-Miranda, Nasser and Naramoto, Satoshi and Wabnik, Krzysztof T and de Rycke, Riet and Kaufmann, Walter and Gütl, Daniel J and Tejos, Ricardo and Grones, Peter and Ke, Meiyu and Chen, Xu and Dettmer, Jan and Friml, Jiří}, issn = {14698137}, journal = {New Phytologist}, number = {1}, pages = {351--369}, publisher = {Wiley}, title = {{Cellular requirements for PIN polar cargo clustering in Arabidopsis thaliana}}, doi = {10.1111/nph.16887}, volume = {229}, year = {2021}, } @article{9332, abstract = {Lateral root (LR) formation is an example of a plant post-embryonic organogenesis event. LRs are issued from non-dividing cells entering consecutive steps of formative divisions, proliferation and elongation. The chromatin remodeling protein PICKLE (PKL) negatively regulates auxin-mediated LR formation through a mechanism that is not yet known. Here we show that PKL interacts with RETINOBLASTOMA-RELATED 1 (RBR1) to repress the LATERAL ORGAN BOUNDARIES-DOMAIN 16 (LBD16) promoter activity. Since LBD16 function is required for the formative division of LR founder cells, repression mediated by the PKL–RBR1 complex negatively regulates formative division and LR formation. Inhibition of LR formation by PKL–RBR1 is counteracted by auxin, indicating that, in addition to auxin-mediated transcriptional responses, the fine-tuned process of LR formation is also controlled at the chromatin level in an auxin-signaling dependent manner.}, author = {Ötvös, Krisztina and Miskolczi, Pál and Marhavý, Peter and Cruz-Ramírez, Alfredo and Benková, Eva and Robert, Stéphanie and Bakó, László}, issn = {1422-0067}, journal = {International Journal of Molecular Sciences}, number = {8}, publisher = {MDPI}, title = {{Pickle recruits retinoblastoma related 1 to control lateral root formation in arabidopsis}}, doi = {10.3390/ijms22083862}, volume = {22}, year = {2021}, } @article{10270, abstract = {Plants develop new organs to adjust their bodies to dynamic changes in the environment. How independent organs achieve anisotropic shapes and polarities is poorly understood. To address this question, we constructed a mechano-biochemical model for Arabidopsis root meristem growth that integrates biologically plausible principles. Computer model simulations demonstrate how differential growth of neighboring tissues results in the initial symmetry-breaking leading to anisotropic root growth. Furthermore, the root growth feeds back on a polar transport network of the growth regulator auxin. Model, predictions are in close agreement with in vivo patterns of anisotropic growth, auxin distribution, and cell polarity, as well as several root phenotypes caused by chemical, mechanical, or genetic perturbations. Our study demonstrates that the combination of tissue mechanics and polar auxin transport organizes anisotropic root growth and cell polarities during organ outgrowth. Therefore, a mobile auxin signal transported through immobile cells drives polarity and growth mechanics to coordinate complex organ development.}, author = {Marconi, Marco and Gallemi, Marçal and Benková, Eva and Wabnik, Krzysztof}, issn = {2050-084X}, journal = {eLife}, publisher = {eLife Sciences Publications}, title = {{A coupled mechano-biochemical model for cell polarity guided anisotropic root growth}}, doi = {10.7554/elife.72132}, volume = {10}, year = {2021}, } @article{9212, abstract = {Plant fitness is largely dependent on the root, the underground organ, which, besides its anchoring function, supplies the plant body with water and all nutrients necessary for growth and development. To exploit the soil effectively, roots must constantly integrate environmental signals and react through adjustment of growth and development. Important components of the root management strategy involve a rapid modulation of the root growth kinetics and growth direction, as well as an increase of the root system radius through formation of lateral roots (LRs). At the molecular level, such a fascinating growth and developmental flexibility of root organ requires regulatory networks that guarantee stability of the developmental program but also allows integration of various environmental inputs. The plant hormone auxin is one of the principal endogenous regulators of root system architecture by controlling primary root growth and formation of LR. In this review, we discuss recent progress in understanding molecular networks where auxin is one of the main players shaping the root system and acting as mediator between endogenous cues and environmental factors.}, author = {Cavallari, Nicola and Artner, Christina and Benková, Eva}, issn = {1943-0264}, journal = {Cold Spring Harbor Perspectives in Biology}, number = {7}, publisher = {Cold Spring Harbor Laboratory Press}, title = {{Auxin-regulated lateral root organogenesis}}, doi = {10.1101/cshperspect.a039941}, volume = {13}, year = {2021}, } @article{9986, abstract = {Size control is a fundamental question in biology, showing incremental complexity in plants, whose cells possess a rigid cell wall. The phytohormone auxin is a vital growth regulator with central importance for differential growth control. Our results indicate that auxin-reliant growth programs affect the molecular complexity of xyloglucans, the major type of cell wall hemicellulose in eudicots. Auxin-dependent induction and repression of growth coincide with reduced and enhanced molecular complexity of xyloglucans, respectively. In agreement with a proposed function in growth control, genetic interference with xyloglucan side decorations distinctly modulates auxin-dependent differential growth rates. Our work proposes that auxin-dependent growth programs have a spatially defined effect on xyloglucan’s molecular structure, which in turn affects cell wall mechanics and specifies differential, gravitropic hypocotyl growth.}, author = {Velasquez, Silvia Melina and Guo, Xiaoyuan and Gallemi, Marçal and Aryal, Bibek and Venhuizen, Peter and Barbez, Elke and Dünser, Kai Alexander and Darino, Martin and Pӗnčík, Aleš and Novák, Ondřej and Kalyna, Maria and Mouille, Gregory and Benková, Eva and Bhalerao, Rishikesh P. and Mravec, Jozef and Kleine-Vehn, Jürgen}, issn = {1422-0067}, journal = {International Journal of Molecular Sciences}, keywords = {auxin, growth, cell wall, xyloglucans, hypocotyls, gravitropism}, number = {17}, publisher = {MDPI}, title = {{Xyloglucan remodeling defines auxin-dependent differential tissue expansion in plants}}, doi = {10.3390/ijms22179222}, volume = {22}, year = {2021}, } @article{9887, abstract = {Clathrin-mediated endocytosis is the major route of entry of cargos into cells and thus underpins many physiological processes. During endocytosis, an area of flat membrane is remodeled by proteins to create a spherical vesicle against intracellular forces. The protein machinery which mediates this membrane bending in plants is unknown. However, it is known that plant endocytosis is actin independent, thus indicating that plants utilize a unique mechanism to mediate membrane bending against high-turgor pressure compared to other model systems. Here, we investigate the TPLATE complex, a plant-specific endocytosis protein complex. It has been thought to function as a classical adaptor functioning underneath the clathrin coat. However, by using biochemical and advanced live microscopy approaches, we found that TPLATE is peripherally associated with clathrin-coated vesicles and localizes at the rim of endocytosis events. As this localization is more fitting to the protein machinery involved in membrane bending during endocytosis, we examined cells in which the TPLATE complex was disrupted and found that the clathrin structures present as flat patches. This suggests a requirement of the TPLATE complex for membrane bending during plant clathrin–mediated endocytosis. Next, we used in vitro biophysical assays to confirm that the TPLATE complex possesses protein domains with intrinsic membrane remodeling activity. These results redefine the role of the TPLATE complex and implicate it as a key component of the evolutionarily distinct plant endocytosis mechanism, which mediates endocytic membrane bending against the high-turgor pressure in plant cells.}, author = {Johnson, Alexander J and Dahhan, Dana A and Gnyliukh, Nataliia and Kaufmann, Walter and Zheden, Vanessa and Costanzo, Tommaso and Mahou, Pierre and Hrtyan, Mónika and Wang, Jie and Aguilera Servin, Juan L and van Damme, Daniël and Beaurepaire, Emmanuel and Loose, Martin and Bednarek, Sebastian Y and Friml, Jiří}, issn = {1091-6490}, journal = {Proceedings of the National Academy of Sciences}, number = {51}, publisher = {National Academy of Sciences}, title = {{The TPLATE complex mediates membrane bending during plant clathrin-mediated endocytosis}}, doi = {10.1073/pnas.2113046118}, volume = {118}, year = {2021}, } @article{9010, abstract = {Availability of the essential macronutrient nitrogen in soil plays a critical role in plant growth, development, and impacts agricultural productivity. Plants have evolved different strategies for sensing and responding to heterogeneous nitrogen distribution. Modulation of root system architecture, including primary root growth and branching, is among the most essential plant adaptions to ensure adequate nitrogen acquisition. However, the immediate molecular pathways coordinating the adjustment of root growth in response to distinct nitrogen sources, such as nitrate or ammonium, are poorly understood. Here, we show that growth as manifested by cell division and elongation is synchronized by coordinated auxin flux between two adjacent outer tissue layers of the root. This coordination is achieved by nitrate‐dependent dephosphorylation of the PIN2 auxin efflux carrier at a previously uncharacterized phosphorylation site, leading to subsequent PIN2 lateralization and thereby regulating auxin flow between adjacent tissues. A dynamic computer model based on our experimental data successfully recapitulates experimental observations. Our study provides mechanistic insights broadening our understanding of root growth mechanisms in dynamic environments.}, author = {Ötvös, Krisztina and Marconi, Marco and Vega, Andrea and O’Brien, Jose and Johnson, Alexander J and Abualia, Rashed and Antonielli, Livio and Montesinos López, Juan C and Zhang, Yuzhou and Tan, Shutang and Cuesta, Candela and Artner, Christina and Bouguyon, Eleonore and Gojon, Alain and Friml, Jiří and Gutiérrez, Rodrigo A. and Wabnik, Krzysztof T and Benková, Eva}, issn = {14602075}, journal = {EMBO Journal}, number = {3}, publisher = {Embo Press}, title = {{Modulation of plant root growth by nitrogen source-defined regulation of polar auxin transport}}, doi = {10.15252/embj.2020106862}, volume = {40}, year = {2021}, } @article{9913, abstract = {Nitrate commands genome-wide gene expression changes that impact metabolism, physiology, plant growth, and development. In an effort to identify new components involved in nitrate responses in plants, we analyze the Arabidopsis thaliana root phosphoproteome in response to nitrate treatments via liquid chromatography coupled to tandem mass spectrometry. 176 phosphoproteins show significant changes at 5 or 20 min after nitrate treatments. Proteins identified by 5 min include signaling components such as kinases or transcription factors. In contrast, by 20 min, proteins identified were associated with transporter activity or hormone metabolism functions, among others. The phosphorylation profile of NITRATE TRANSPORTER 1.1 (NRT1.1) mutant plants was significantly altered as compared to wild-type plants, confirming its key role in nitrate signaling pathways that involves phosphorylation changes. Integrative bioinformatics analysis highlights auxin transport as an important mechanism modulated by nitrate signaling at the post-translational level. We validated a new phosphorylation site in PIN2 and provide evidence that it functions in primary and lateral root growth responses to nitrate.}, author = {Vega, Andrea and Fredes, Isabel and O’Brien, José and Shen, Zhouxin and Ötvös, Krisztina and Abualia, Rashed and Benková, Eva and Briggs, Steven P. and Gutiérrez, Rodrigo A.}, issn = {1469-3178}, journal = {EMBO Reports}, number = {9}, publisher = {Wiley}, title = {{Nitrate triggered phosphoproteome changes and a PIN2 phosphosite modulating root system architecture}}, doi = {10.15252/embr.202051813}, volume = {22}, year = {2021}, } @phdthesis{10303, abstract = {Nitrogen is an essential macronutrient determining plant growth, development and affecting agricultural productivity. Root, as a hub that perceives and integrates local and systemic signals on the plant’s external and endogenous nitrogen resources, communicates with other plant organs to consolidate their physiology and development in accordance with actual nitrogen balance. Over the last years, numerous studies demonstrated that these comprehensive developmental adaptations rely on the interaction between pathways controlling nitrogen homeostasis and hormonal networks acting globally in the plant body. However, molecular insights into how the information about the nitrogen status is translated through hormonal pathways into specific developmental output are lacking. In my work, I addressed so far poorly understood mechanisms underlying root-to-shoot communication that lead to a rapid re-adjustment of shoot growth and development after nitrate provision. Applying a combination of molecular, cell, and developmental biology approaches, genetics and grafting experiments as well as hormonal analytics, I identified and characterized an unknown molecular framework orchestrating shoot development with a root nitrate sensory system. }, author = {Abualia, Rashed}, issn = {2663-337X}, pages = {139}, publisher = {Institute of Science and Technology Austria}, title = {{Role of hormones in nitrate regulated growth}}, doi = {10.15479/at:ista:10303}, year = {2021}, } @phdthesis{10135, abstract = {Plants maintain the capacity to develop new organs e.g. lateral roots post-embryonically throughout their whole life and thereby flexibly adapt to ever-changing environmental conditions. Plant hormones auxin and cytokinin are the main regulators of the lateral root organogenesis. Additionally to their solo activities, the interaction between auxin and cytokinin plays crucial role in fine-tuning of lateral root development and growth. In particular, cytokinin modulates auxin distribution within the developing lateral root by affecting the endomembrane trafficking of auxin transporter PIN1 and promoting its vacuolar degradation (Marhavý et al., 2011, 2014). This effect is independent of transcription and translation. Therefore, it suggests novel, non-canonical cytokinin activity occuring possibly on the posttranslational level. Impact of cytokinin and other plant hormones on auxin transporters (including PIN1) on the posttranslational level is described in detail in the introduction part of this thesis in a form of a review (Semeradova et al., 2020). To gain insights into the molecular machinery underlying cytokinin effect on the endomembrane trafficking in the plant cell, in particular on the PIN1 degradation, we conducted two large proteomic screens: 1) Identification of cytokinin binding proteins using chemical proteomics. 2) Monitoring of proteomic and phosphoproteomic changes upon cytokinin treatment. In the first screen, we identified DYNAMIN RELATED PROTEIN 2A (DRP2A). We found that DRP2A plays a role in cytokinin regulated processes during the plant growth and that cytokinin treatment promotes destabilization of DRP2A protein. However, the role of DRP2A in the PIN1 degradation remains to be elucidated. In the second screen, we found VACUOLAR PROTEIN SORTING 9A (VPS9A). VPS9a plays crucial role in plant’s response to cytokin and in cytokinin mediated PIN1 degradation. Altogether, we identified proteins, which bind to cytokinin and proteins that in response to cytokinin exhibit significantly changed abundance or phosphorylation pattern. By combining information from these two screens, we can pave our way towards understanding of noncanonical cytokinin effects.}, author = {Semerádová, Hana}, isbn = {978-3-99078-014-5}, issn = {2663-337X}, publisher = {Institute of Science and Technology Austria}, title = {{Molecular mechanisms of the cytokinin-regulated endomembrane trafficking to coordinate plant organogenesis}}, doi = {10.15479/at:ista:10135}, year = {2021}, } @article{7350, abstract = {The ability to sense environmental temperature and to coordinate growth and development accordingly, is critical to the reproductive success of plants. Flowering time is regulated at the level of gene expression by a complex network of factors that integrate environmental and developmental cues. One of the main players, involved in modulating flowering time in response to changes in ambient temperature is FLOWERING LOCUS M (FLM). FLM transcripts can undergo extensive alternative splicing producing multiple variants, of which FLM-β and FLM-δ are the most representative. While FLM-β codes for the flowering repressor FLM protein, translation of FLM-δ has the opposite effect on flowering. Here we show that the cyclin-dependent kinase G2 (CDKG2), together with its cognate cyclin, CYCLYN L1 (CYCL1) affects the alternative splicing of FLM, balancing the levels of FLM-β and FLM-δ across the ambient temperature range. In the absence of the CDKG2/CYCL1 complex, FLM-β expression is reduced while FLM-δ is increased in a temperature dependent manner and these changes are associated with an early flowering phenotype in the cdkg2 mutant lines. In addition, we found that transcript variants retaining the full FLM intron 1 are sequestered in the cell nucleus. Strikingly, FLM intron 1 splicing is also regulated by CDKG2/CYCL1. Our results provide evidence that temperature and CDKs regulate the alternative splicing of FLM, contributing to flowering time definition.}, author = {Nibau, Candida and Gallemi, Marçal and Dadarou, Despoina and Doonan, John H. and Cavallari, Nicola}, issn = {1664-462X}, journal = {Frontiers in Plant Science}, publisher = {Frontiers Media}, title = {{Thermo-sensitive alternative splicing of FLOWERING LOCUS M is modulated by cyclin-dependent kinase G2}}, doi = {10.3389/fpls.2019.01680}, volume = {10}, year = {2020}, } @article{7805, abstract = {Plants as non-mobile organisms constantly integrate varying environmental signals to flexibly adapt their growth and development. Local fluctuations in water and nutrient availability, sudden changes in temperature or other abiotic and biotic stresses can trigger changes in the growth of plant organs. Multiple mutually interconnected hormonal signaling cascades act as essential endogenous translators of these exogenous signals in the adaptive responses of plants. Although the molecular backbones of hormone transduction pathways have been identified, the mechanisms underlying their interactions are largely unknown. Here, using genome wide transcriptome profiling we identify an auxin and cytokinin cross-talk component; SYNERGISTIC ON AUXIN AND CYTOKININ 1 (SYAC1), whose expression in roots is strictly dependent on both of these hormonal pathways. We show that SYAC1 is a regulator of secretory pathway, whose enhanced activity interferes with deposition of cell wall components and can fine-tune organ growth and sensitivity to soil pathogens.}, author = {Hurny, Andrej and Cuesta, Candela and Cavallari, Nicola and Ötvös, Krisztina and Duclercq, Jerome and Dokládal, Ladislav and Montesinos López, Juan C and Gallemi, Marçal and Semeradova, Hana and Rauter, Thomas and Stenzel, Irene and Persiau, Geert and Benade, Freia and Bhalearo, Rishikesh and Sýkorová, Eva and Gorzsás, András and Sechet, Julien and Mouille, Gregory and Heilmann, Ingo and De Jaeger, Geert and Ludwig-Müller, Jutta and Benková, Eva}, issn = {20411723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Synergistic on Auxin and Cytokinin 1 positively regulates growth and attenuates soil pathogen resistance}}, doi = {10.1038/s41467-020-15895-5}, volume = {11}, year = {2020}, } @article{7948, abstract = {In agricultural systems, nitrate is the main source of nitrogen available for plants. Besides its role as a nutrient, nitrate has been shown to act as a signal molecule for plant growth, development and stress responses. In Arabidopsis, the NRT1.1 nitrate transceptor represses lateral root (LR) development at low nitrate availability by promoting auxin basipetal transport out of the LR primordia (LRPs). In addition, our present study shows that NRT1.1 acts as a negative regulator of the TAR2 auxin biosynthetic gene expression in the root stele. This is expected to repress local auxin biosynthesis and thus to reduce acropetal auxin supply to the LRPs. Moreover, NRT1.1 also negatively affects expression of the LAX3 auxin influx carrier, thus preventing cell wall remodeling required for overlying tissues separation during LRP emergence. Both NRT1.1-mediated repression of TAR2 and LAX3 are suppressed at high nitrate availability, resulting in the nitrate induction of TAR2 and LAX3 expression that is required for optimal stimulation of LR development by nitrate. Altogether, our results indicate that the NRT1.1 transceptor coordinately controls several crucial auxin-associated processes required for LRP development, and as a consequence that NRT1.1 plays a much more integrated role than previously anticipated in regulating the nitrate response of root system architecture.}, author = {Maghiaoui, A and Bouguyon, E and Cuesta, Candela and Perrine-Walker, F and Alcon, C and Krouk, G and Benková, Eva and Nacry, P and Gojon, A and Bach, L}, issn = {1460-2431}, journal = {Journal of Experimental Botany}, number = {15}, pages = {4480--4494}, publisher = {Oxford University Press}, title = {{The Arabidopsis NRT1.1 transceptor coordinately controls auxin biosynthesis and transport to regulate root branching in response to nitrate}}, doi = {10.1093/jxb/eraa242}, volume = {71}, year = {2020}, } @article{8336, abstract = {Plant hormone cytokinins are perceived by a subfamily of sensor histidine kinases (HKs), which via a two-component phosphorelay cascade activate transcriptional responses in the nucleus. Subcellular localization of the receptors proposed the endoplasmic reticulum (ER) membrane as a principal cytokinin perception site, while study of cytokinin transport pointed to the plasma membrane (PM)-mediated cytokinin signalling. Here, by detailed monitoring of subcellular localizations of the fluorescently labelled natural cytokinin probe and the receptor ARABIDOPSIS HISTIDINE KINASE 4 (CRE1/AHK4) fused to GFP reporter, we show that pools of the ER-located cytokinin receptors can enter the secretory pathway and reach the PM in cells of the root apical meristem, and the cell plate of dividing meristematic cells. Brefeldin A (BFA) experiments revealed vesicular recycling of the receptor and its accumulation in BFA compartments. We provide a revised view on cytokinin signalling and the possibility of multiple sites of perception at PM and ER.}, author = {Kubiasova, Karolina and Montesinos López, Juan C and Šamajová, Olga and Nisler, Jaroslav and Mik, Václav and Semeradova, Hana and Plíhalová, Lucie and Novák, Ondřej and Marhavý, Peter and Cavallari, Nicola and Zalabák, David and Berka, Karel and Doležal, Karel and Galuszka, Petr and Šamaj, Jozef and Strnad, Miroslav and Benková, Eva and Plíhal, Ondřej and Spíchal, Lukáš}, issn = {20411723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Cytokinin fluoroprobe reveals multiple sites of cytokinin perception at plasma membrane and endoplasmic reticulum}}, doi = {10.1038/s41467-020-17949-0}, volume = {11}, year = {2020}, } @article{8924, abstract = {Maintaining fertility in a fluctuating environment is key to the reproductive success of flowering plants. Meiosis and pollen formation are particularly sensitive to changes in growing conditions, especially temperature. We have previously identified cyclin-dependent kinase G1 (CDKG1) as a master regulator of temperature-dependent meiosis and this may involve the regulation of alternative splicing (AS), including of its own transcript. CDKG1 mRNA can undergo several AS events, potentially producing two protein variants: CDKG1L and CDKG1S, differing in their N-terminal domain which may be involved in co-factor interaction. In leaves, both isoforms have distinct temperature-dependent functions on target mRNA processing, but their role in pollen development is unknown. In the present study, we characterize the role of CDKG1L and CDKG1S in maintaining Arabidopsis fertility. We show that the long (L) form is necessary and sufficient to rescue the fertility defects of the cdkg1-1 mutant, while the short (S) form is unable to rescue fertility. On the other hand, an extra copy of CDKG1L reduces fertility. In addition, mutation of the ATP binding pocket of the kinase indicates that kinase activity is necessary for the function of CDKG1. Kinase mutants of CDKG1L and CDKG1S correctly localize to the cell nucleus and nucleus and cytoplasm, respectively, but are unable to rescue either the fertility or the splicing defects of the cdkg1-1 mutant. Furthermore, we show that there is partial functional overlap between CDKG1 and its paralog CDKG2 that could in part be explained by overlapping gene expression.}, author = {Nibau, Candida and Dadarou, Despoina and Kargios, Nestoras and Mallioura, Areti and Fernandez-Fuentes, Narcis and Cavallari, Nicola and Doonan, John H.}, issn = {1664-462X}, journal = {Frontiers in Plant Science}, publisher = {Frontiers}, title = {{A functional kinase is necessary for cyclin-dependent kinase G1 (CDKG1) to maintain fertility at high ambient temperature in Arabidopsis}}, doi = {10.3389/fpls.2020.586870}, volume = {11}, year = {2020}, } @article{8142, abstract = {Cell production and differentiation for the acquisition of specific functions are key features of living systems. The dynamic network of cellular microtubules provides the necessary platform to accommodate processes associated with the transition of cells through the individual phases of cytogenesis. Here, we show that the plant hormone cytokinin fine‐tunes the activity of the microtubular cytoskeleton during cell differentiation and counteracts microtubular rearrangements driven by the hormone auxin. The endogenous upward gradient of cytokinin activity along the longitudinal growth axis in Arabidopsis thaliana roots correlates with robust rearrangements of the microtubule cytoskeleton in epidermal cells progressing from the proliferative to the differentiation stage. Controlled increases in cytokinin activity result in premature re‐organization of the microtubule network from transversal to an oblique disposition in cells prior to their differentiation, whereas attenuated hormone perception delays cytoskeleton conversion into a configuration typical for differentiated cells. Intriguingly, cytokinin can interfere with microtubules also in animal cells, such as leukocytes, suggesting that a cytokinin‐sensitive control pathway for the microtubular cytoskeleton may be at least partially conserved between plant and animal cells.}, author = {Montesinos López, Juan C and Abuzeineh, A and Kopf, Aglaja and Juanes Garcia, Alba and Ötvös, Krisztina and Petrášek, J and Sixt, Michael K and Benková, Eva}, issn = {1460-2075}, journal = {The Embo Journal}, number = {17}, publisher = {Embo Press}, title = {{Phytohormone cytokinin guides microtubule dynamics during cell progression from proliferative to differentiated stage}}, doi = {10.15252/embj.2019104238}, volume = {39}, year = {2020}, } @article{15037, abstract = {Protein abundance and localization at the plasma membrane (PM) shapes plant development and mediates adaptation to changing environmental conditions. It is regulated by ubiquitination, a post-translational modification crucial for the proper sorting of endocytosed PM proteins to the vacuole for subsequent degradation. To understand the significance and the variety of roles played by this reversible modification, the function of ubiquitin receptors, which translate the ubiquitin signature into a cellular response, needs to be elucidated. In this study, we show that TOL (TOM1-like) proteins function in plants as multivalent ubiquitin receptors, governing ubiquitinated cargo delivery to the vacuole via the conserved Endosomal Sorting Complex Required for Transport (ESCRT) pathway. TOL2 and TOL6 interact with components of the ESCRT machinery and bind to K63-linked ubiquitin via two tandemly arranged conserved ubiquitin-binding domains. Mutation of these domains results not only in a loss of ubiquitin binding but also altered localization, abolishing TOL6 ubiquitin receptor activity. Function and localization of TOL6 is itself regulated by ubiquitination, whereby TOL6 ubiquitination potentially modulates degradation of PM-localized cargoes, assisting in the fine-tuning of the delicate interplay between protein recycling and downregulation. Taken together, our findings demonstrate the function and regulation of a ubiquitin receptor that mediates vacuolar degradation of PM proteins in higher plants.}, author = {Moulinier-Anzola, Jeanette and Schwihla, Maximilian and De-Araújo, Lucinda and Artner, Christina and Jörg, Lisa and Konstantinova, Nataliia and Luschnig, Christian and Korbei, Barbara}, issn = {1674-2052}, journal = {Molecular Plant}, keywords = {Plant Science, Molecular Biology}, number = {5}, pages = {717--731}, publisher = {Elsevier}, title = {{TOLs function as ubiquitin receptors in the early steps of the ESCRT pathway in higher plants}}, doi = {10.1016/j.molp.2020.02.012}, volume = {13}, year = {2020}, } @article{8002, abstract = {Wound healing in plant tissues, consisting of rigid cell wall-encapsulated cells, represents a considerable challenge and occurs through largely unknown mechanisms distinct from those in animals. Owing to their inability to migrate, plant cells rely on targeted cell division and expansion to regenerate wounds. Strict coordination of these wound-induced responses is essential to ensure efficient, spatially restricted wound healing. Single-cell tracking by live imaging allowed us to gain mechanistic insight into the wound perception and coordination of wound responses after laser-based wounding in Arabidopsis root. We revealed a crucial contribution of the collapse of damaged cells in wound perception and detected an auxin increase specific to cells immediately adjacent to the wound. This localized auxin increase balances wound-induced cell expansion and restorative division rates in a dose-dependent manner, leading to tumorous overproliferation when the canonical TIR1 auxin signaling is disrupted. Auxin and wound-induced turgor pressure changes together also spatially define the activation of key components of regeneration, such as the transcription regulator ERF115. Our observations suggest that the wound signaling involves the sensing of collapse of damaged cells and a local auxin signaling activation to coordinate the downstream transcriptional responses in the immediate wound vicinity.}, author = {Hörmayer, Lukas and Montesinos López, Juan C and Marhavá, Petra and Benková, Eva and Yoshida, Saiko and Friml, Jiří}, issn = {1091-6490}, journal = {Proceedings of the National Academy of Sciences}, number = {26}, publisher = {Proceedings of the National Academy of Sciences}, title = {{Wounding-induced changes in cellular pressure and localized auxin signalling spatially coordinate restorative divisions in roots}}, doi = {10.1073/pnas.2003346117}, volume = {117}, year = {2020}, } @article{7427, abstract = {Plants, like other multicellular organisms, survive through a delicate balance between growth and defense against pathogens. Salicylic acid (SA) is a major defense signal in plants, and the perception mechanism as well as downstream signaling activating the immune response are known. Here, we identify a parallel SA signaling that mediates growth attenuation. SA directly binds to A subunits of protein phosphatase 2A (PP2A), inhibiting activity of this complex. Among PP2A targets, the PIN2 auxin transporter is hyperphosphorylated in response to SA, leading to changed activity of this important growth regulator. Accordingly, auxin transport and auxin-mediated root development, including growth, gravitropic response, and lateral root organogenesis, are inhibited. This study reveals how SA, besides activating immunity, concomitantly attenuates growth through crosstalk with the auxin distribution network. Further analysis of this dual role of SA and characterization of additional SA-regulated PP2A targets will provide further insights into mechanisms maintaining a balance between growth and defense.}, author = {Tan, Shutang and Abas, Melinda F and Verstraeten, Inge and Glanc, Matous and Molnar, Gergely and Hajny, Jakub and Lasák, Pavel and Petřík, Ivan and Russinova, Eugenia and Petrášek, Jan and Novák, Ondřej and Pospíšil, Jiří and Friml, Jiří}, issn = {09609822}, journal = {Current Biology}, number = {3}, pages = {381--395.e8}, publisher = {Cell Press}, title = {{Salicylic acid targets protein phosphatase 2A to attenuate growth in plants}}, doi = {10.1016/j.cub.2019.11.058}, volume = {30}, year = {2020}, } @article{9160, abstract = {Auxin is a key hormonal regulator, that governs plant growth and development in concert with other hormonal pathways. The unique feature of auxin is its polar, cell-to-cell transport that leads to the formation of local auxin maxima and gradients, which coordinate initiation and patterning of plant organs. The molecular machinery mediating polar auxin transport is one of the important points of interaction with other hormones. Multiple hormonal pathways converge at the regulation of auxin transport and form a regulatory network that integrates various developmental and environmental inputs to steer plant development. In this review, we discuss recent advances in understanding the mechanisms that underlie regulation of polar auxin transport by multiple hormonal pathways. Specifically, we focus on the post-translational mechanisms that contribute to fine-tuning of the abundance and polarity of auxin transporters at the plasma membrane and thereby enable rapid modification of the auxin flow to coordinate plant growth and development.}, author = {Semeradova, Hana and Montesinos López, Juan C and Benková, Eva}, issn = {2590-3462}, journal = {Plant Communications}, number = {3}, publisher = {Elsevier}, title = {{All roads lead to auxin: Post-translational regulation of auxin transport by multiple hormonal pathways}}, doi = {10.1016/j.xplc.2020.100048}, volume = {1}, year = {2020}, } @article{6023, abstract = {Multicellular development requires coordinated cell polarization relative to body axes, and translation to oriented cell division 1–3 . In plants, it is unknown how cell polarities are connected to organismal axes and translated to division. Here, we identify Arabidopsis SOSEKI proteins that integrate apical–basal and radial organismal axes to localize to polar cell edges. Localization does not depend on tissue context, requires cell wall integrity and is defined by a transferrable, protein-specific motif. A Domain of Unknown Function in SOSEKI proteins resembles the DIX oligomerization domain in the animal Dishevelled polarity regulator. The DIX-like domain self-interacts and is required for edge localization and for influencing division orientation, together with a second domain that defines the polar membrane domain. Our work shows that SOSEKI proteins locally interpret global polarity cues and can influence cell division orientation. Furthermore, this work reveals that, despite fundamental differences, cell polarity mechanisms in plants and animals converge on a similar protein domain.}, author = {Yoshida, Saiko and Van Der Schuren, Alja and Van Dop, Maritza and Van Galen, Luc and Saiga, Shunsuke and Adibi, Milad and Möller, Barbara and Ten Hove, Colette A. and Marhavy, Peter and Smith, Richard and Friml, Jiří and Weijers, Dolf}, journal = {Nature Plants}, number = {2}, pages = {160--166}, publisher = {Springer Nature}, title = {{A SOSEKI-based coordinate system interprets global polarity cues in arabidopsis}}, doi = {10.1038/s41477-019-0363-6}, volume = {5}, year = {2019}, } @article{6897, abstract = {The apical hook is a transiently formed structure that plays a protective role when the germinating seedling penetrates through the soil towards the surface. Crucial for proper bending is the local auxin maxima, which defines the concave (inner) side of the hook curvature. As no sign of asymmetric auxin distribution has been reported in embryonic hypocotyls prior to hook formation, the question of how auxin asymmetry is established in the early phases of seedling germination remains largely unanswered. Here, we analyzed the auxin distribution and expression of PIN auxin efflux carriers from early phases of germination, and show that bending of the root in response to gravity is the crucial initial cue that governs the hypocotyl bending required for apical hook formation. Importantly, polar auxin transport machinery is established gradually after germination starts as a result of tight root-hypocotyl interaction and a proper balance between abscisic acid and gibberellins.}, author = {Zhu, Qiang and Gallemi, Marçal and Pospíšil, Jiří and Žádníková, Petra and Strnad, Miroslav and Benková, Eva}, issn = {14779129}, journal = {Development}, number = {17}, publisher = {The Company of Biologists}, title = {{Root gravity response module guides differential growth determining both root bending and apical hook formation in Arabidopsis}}, doi = {10.1242/dev.175919}, volume = {146}, year = {2019}, } @article{6920, author = {Artner, Christina and Benková, Eva}, issn = {1674-2052}, journal = {Molecular Plant}, number = {10}, pages = {1312--1314}, publisher = {Cell Press}, title = {{Ethylene and cytokinin - partners in root growth regulation}}, doi = {10.1016/j.molp.2019.09.003}, volume = {12}, year = {2019}, } @article{7394, author = {Benková, Eva and Dagdas, Yasin}, issn = {1369-5266}, journal = {Current Opinion in Plant Biology}, number = {12}, pages = {A1--A2}, publisher = {Elsevier}, title = {{Editorial overview: Cell biology in the era of omics?}}, doi = {10.1016/j.pbi.2019.11.002}, volume = {52}, year = {2019}, } @article{6351, abstract = {A process of restorative patterning in plant roots correctly replaces eliminated cells to heal local injuries despite the absence of cell migration, which underpins wound healing in animals. Patterning in plants relies on oriented cell divisions and acquisition of specific cell identities. Plants regularly endure wounds caused by abiotic or biotic environmental stimuli and have developed extraordinary abilities to restore their tissues after injuries. Here, we provide insight into a mechanism of restorative patterning that repairs tissues after wounding. Laser-assisted elimination of different cells in Arabidopsis root combined with live-imaging tracking during vertical growth allowed analysis of the regeneration processes in vivo. Specifically, the cells adjacent to the inner side of the injury re-activated their stem cell transcriptional programs. They accelerated their progression through cell cycle, coordinately changed the cell division orientation, and ultimately acquired de novo the correct cell fates to replace missing cells. These observations highlight existence of unknown intercellular positional signaling and demonstrate the capability of specified cells to re-acquire stem cell programs as a crucial part of the plant-specific mechanism of wound healing.}, author = {Marhavá, Petra and Hörmayer, Lukas and Yoshida, Saiko and Marhavy, Peter and Benková, Eva and Friml, Jiří}, issn = {10974172}, journal = {Cell}, number = {4}, pages = {957--969.e13}, publisher = {Elsevier}, title = {{Re-activation of stem cell pathways for pattern restoration in plant wound healing}}, doi = {10.1016/j.cell.2019.04.015}, volume = {177}, year = {2019}, } @article{277, abstract = {Arabidopsis and human ARM protein interact with telomerase. Deregulated mRNA levels of DNA repair and ribosomal protein genes in an Arabidopsis arm mutant suggest non-telomeric ARM function. The human homolog ARMC6 interacts with hTRF2. Abstract: Telomerase maintains telomeres and has proposed non-telomeric functions. We previously identified interaction of the C-terminal domain of Arabidopsis telomerase reverse transcriptase (AtTERT) with an armadillo/β-catenin-like repeat (ARM) containing protein. Here we explore protein–protein interactions of the ARM protein, AtTERT domains, POT1a, TRF-like family and SMH family proteins, and the chromatin remodeling protein CHR19 using bimolecular fluorescence complementation (BiFC), yeast two-hybrid (Y2H) analysis, and co-immunoprecipitation. The ARM protein interacts with both the N- and C-terminal domains of AtTERT in different cellular compartments. ARM interacts with CHR19 and TRF-like I family proteins that also bind AtTERT directly or through interaction with POT1a. The putative human ARM homolog co-precipitates telomerase activity and interacts with hTRF2 protein in vitro. Analysis of Arabidopsis arm mutants shows no obvious changes in telomere length or telomerase activity, suggesting that ARM is not essential for telomere maintenance. The observed interactions with telomerase and Myb-like domain proteins (TRF-like family I) may therefore reflect possible non-telomeric functions. Transcript levels of several DNA repair and ribosomal genes are affected in arm mutants, and ARM, likely in association with other proteins, suppressed expression of XRCC3 and RPSAA promoter constructs in luciferase reporter assays. In conclusion, ARM can participate in non-telomeric functions of telomerase, and can also perform its own telomerase-independent functions.}, author = {Dokládal, Ladislav and Benková, Eva and Honys, David and Dupláková, Nikoleta and Lee, Lan and Gelvin, Stanton and Sýkorová, Eva}, journal = {Plant Molecular Biology}, number = {5}, pages = {407 -- 420}, publisher = {Springer}, title = {{An armadillo-domain protein participates in a telomerase interaction network}}, doi = {10.1007/s11103-018-0747-4}, volume = {97}, year = {2018}, } @article{42, abstract = {Seeds derive from ovules upon fertilization and therefore the total number of ovules determines the final seed yield, a fundamental trait in crop plants. Among the factors that co-ordinate the process of ovule formation, the transcription factors CUP-SHAPED COTYLEDON 1 (CUC1) and CUC2 and the hormone cytokinin (CK) have a particularly prominent role. Indeed, the absence of both CUC1 and CUC2 causes a severe reduction in ovule number, a phenotype that can be rescued by CK treatment. In this study, we combined CK quantification with an integrative genome-wide target identification approach to select Arabidopsis genes regulated by CUCs that are also involved in CK metabolism. We focused our attention on the functional characterization of UDP-GLUCOSYL TRANSFERASE 85A3 (UGT85A3) and UGT73C1, which are up-regulated in the absence of CUC1 and CUC2 and encode enzymes able to catalyse CK inactivation by O-glucosylation. Our results demonstrate a role for these UGTs as a link between CUCs and CK homeostasis, and highlight the importance of CUCs and CKs in the determination of seed yield.}, author = {Cucinotta, Mara and Manrique, Silvia and Cuesta, Candela and Benková, Eva and Novák, Ondřej and Colombo, Lucia}, journal = {Journal of Experimental Botany}, number = {21}, pages = {5169 -- 5176}, publisher = {Oxford University Press}, title = {{Cup-shaped Cotyledon1 (CUC1) and CU2 regulate cytokinin homeostasis to determine ovule number in arabidopsis}}, doi = {10.1093/jxb/ery281}, volume = {69}, year = {2018}, } @article{407, abstract = {Isoprenoid cytokinins play a number of crucial roles in the regulation of plant growth and development. To study cytokinin receptor properties in plants, we designed and prepared fluorescent derivatives of 6-[(3-methylbut-2-en-1-yl)amino]purine (N6-isopentenyladenine, iP) with several fluorescent labels attached to the C2 or N9 atom of the purine moiety via a 2- or 6-carbon linker. The fluorescent labels included dansyl (DS), fluorescein (FC), 7-nitrobenzofurazan (NBD), rhodamine B (RhoB), coumarin (Cou), 7-(diethylamino)coumarin (DEAC) and cyanine 5 dye (Cy5). All prepared compounds were screened for affinity for the Arabidopsis thaliana cytokinin receptor (CRE1/AHK4). Although the attachment of the fluorescent labels to iP via the linkers mostly disrupted binding to the receptor, several fluorescent derivatives interacted well. For this reason, three derivatives, two rhodamine B and one 4-chloro-7-nitrobenzofurazan labeled iP were tested for their interaction with CRE1/AHK4 and Zea mays cytokinin receptors in detail. We further showed that the three derivatives were able to activate transcription of cytokinin response regulator ARR5 in Arabidopsis seedlings. The activity of fluorescently labeled cytokinins was compared with corresponding 6-dimethylaminopurine fluorescently labeled negative controls. Selected rhodamine B C2-labeled compounds 17, 18 and 4-chloro-7-nitrobenzofurazan N9-labeled compound 28 and their respective negative controls (19, 20 and 29, respectively) were used for in planta staining experiments in Arabidopsis thaliana cell suspension culture using live cell confocal microscopy.}, author = {Kubiasová, Karolina and Mik, Václav and Nisler, Jaroslav and Hönig, Martin and Husičková, Alexandra and Spíchal, Lukáš and Pěkná, Zuzana and Šamajová, Olga and Doležal, Karel and Plíhal, Ondřej and Benková, Eva and Strnad, Miroslav and Plíhalová, Lucie}, journal = {Phytochemistry}, pages = {1--11}, publisher = {Elsevier}, title = {{Design, synthesis and perception of fluorescently labeled isoprenoid cytokinins}}, doi = {10.1016/j.phytochem.2018.02.015}, volume = {150}, year = {2018}, } @article{283, abstract = {Light represents the principal signal driving circadian clock entrainment. However, how light influences the evolution of the clock remains poorly understood. The cavefish Phreatichthys andruzzii represents a fascinating model to explore how evolution under extreme aphotic conditions shapes the circadian clock, since in this species the clock is unresponsive to light. We have previously demonstrated that loss-of-function mutations targeting non-visual opsins contribute in part to this blind clock phenotype. Here, we have compared orthologs of two core clock genes that play a key role in photic entrainment, cry1a and per2, in both zebrafish and P. andruzzii. We encountered aberrantly spliced variants for the P. andruzzii per2 transcript. The most abundant transcript encodes a truncated protein lacking the C-terminal Cry binding domain and incorporating an intronic, transposon-derived coding sequence. We demonstrate that the transposon insertion leads to a predominantly cytoplasmic localization of the cavefish Per2 protein in contrast to the zebrafish ortholog which is distributed in both the nucleus and cytoplasm. Thus, it seems that during evolution in complete darkness, the photic entrainment pathway of the circadian clock has been subject to mutation at multiple levels, extending from opsin photoreceptors to nuclear effectors.}, author = {Ceinos, Rosa Maria and Frigato, Elena and Pagano, Cristina and Frohlich, Nadine and Negrini, Pietro and Cavallari, Nicola and Vallone, Daniela and Fuselli, Silvia and Bertolucci, Cristiano and Foulkes, Nicholas S}, journal = {Scientific Reports}, number = {1}, publisher = {Nature Publishing Group}, title = {{Mutations in blind cavefish target the light regulated circadian clock gene period 2}}, doi = {10.1038/s41598-018-27080-2}, volume = {8}, year = {2018}, } @article{403, abstract = {The ability to adapt growth and development to temperature variations is crucial to generate plant varieties resilient to predicted temperature changes. However, the mechanisms underlying plant response to progressive increases in temperature have just started to be elucidated. Here, we report that the Cyclin-dependent Kinase G1 (CDKG1) is a central element in a thermo-sensitive mRNA splicing cascade that transduces changes in ambient temperature into differential expression of the fundamental spliceosome component, ATU2AF65A. CDKG1 is alternatively spliced in a temperature-dependent manner. We found that this process is partly dependent on both the Cyclin-dependent Kinase G2 (CDKG2) and the interacting co-factor CYCLIN L1 resulting in two distinct messenger RNAs. Relative abundance of both CDKG1 transcripts correlates with ambient temperature and possibly with different expression levels of the associated protein isoforms. Both CDKG1 alternative transcripts are necessary to fully complement the expression of ATU2AF65A across the temperature range. Our data support a previously unidentified temperature-dependent mechanism based on the alternative splicing of CDKG1 and regulated by CDKG2 and CYCLIN L1. We propose that changes in ambient temperature affect the relative abundance of CDKG1 transcripts and this in turn translates into differential CDKG1 protein expression coordinating the alternative splicing of ATU2AF65A. This article is protected by copyright. All rights reserved.}, author = {Cavallari, Nicola and Nibau, Candida and Fuchs, Armin and Dadarou, Despoina and Barta, Andrea and Doonan, John}, journal = {The Plant Journal}, number = {6}, pages = {1010 -- 1022}, publisher = {Wiley}, title = {{The cyclin‐dependent kinase G group defines a thermo‐sensitive alternative splicing circuit modulating the expression of Arabidopsis ATU 2AF 65A}}, doi = {10.1111/tpj.13914}, volume = {94}, year = {2018}, } @phdthesis{539, abstract = {The whole life cycle of plants as well as their responses to environmental stimuli is governed by a complex network of hormonal regulations. A number of studies have demonstrated an essential role of both auxin and cytokinin in the regulation of many aspects of plant growth and development including embryogenesis, postembryonic organogenic processes such as root, and shoot branching, root and shoot apical meristem activity and phyllotaxis. Over the last decades essential knowledge on the key molecular factors and pathways that spatio-temporally define auxin and cytokinin activities in the plant body has accumulated. However, how both hormonal pathways are interconnected by a complex network of interactions and feedback circuits that determines the final outcome of the individual hormone actions is still largely unknown. Root system architecture establishment and in particular formation of lateral organs is prime example of developmental process at whose regulation both auxin and cytokinin pathways converge. To dissect convergence points and pathways that tightly balance auxin - cytokinin antagonistic activities that determine the root branching pattern transcriptome profiling was applied. Genome wide expression analyses of the xylem pole pericycle, a tissue giving rise to lateral roots, led to identification of genes that are highly responsive to combinatorial auxin and cytokinin treatments and play an essential function in the auxin-cytokinin regulated root branching. SYNERGISTIC AUXIN CYTOKININ 1 (SYAC1) gene, which encodes for a protein of unknown function, was detected among the top candidate genes of which expression was synergistically up-regulated by simultaneous hormonal treatment. Plants with modulated SYAC1 activity exhibit severe defects in the root system establishment and attenuate developmental responses to both auxin and cytokinin. To explore the biological function of the SYAC1, we employed different strategies including expression pattern analysis, subcellular localization and phenotypic analyses of the syac1 loss-of-function and gain-of-function transgenic lines along with the identification of the SYAC1 interaction partners. Detailed functional characterization revealed that SYAC1 acts as a developmentally specific regulator of the secretory pathway to control deposition of cell wall components and thereby rapidly fine tune elongation growth.}, author = {Hurny, Andrej}, issn = {2663-337X}, pages = {147}, publisher = {Institute of Science and Technology Austria}, title = {{Identification and characterization of novel auxin-cytokinin cross-talk components}}, doi = {10.15479/AT:ISTA:th_930}, year = {2018}, } @article{191, abstract = {Intercellular distribution of the plant hormone auxin largely depends on the polar subcellular distribution of the plasma membrane PIN-FORMED (PIN) auxin transporters. PIN polarity switches in response to different developmental and environmental signals have been shown to redirect auxin fluxes mediating certain developmental responses. PIN phosphorylation at different sites and by different kinases is crucial for PIN function. Here we investigate the role of PIN phosphorylation during gravitropic response. Loss- and gain-of-function mutants in PINOID and related kinases but not in D6PK kinase as well as mutations mimicking constitutive dephosphorylated or phosphorylated status of two clusters of predicted phosphorylation sites partially disrupted PIN3 phosphorylation and caused defects in gravitropic bending in roots and hypocotyls. In particular, they impacted PIN3 polarity rearrangements in response to gravity and during feed-back regulation by auxin itself. Thus PIN phosphorylation, besides regulating transport activity and apical-basal targeting, is also important for the rapid polarity switches in response to environmental and endogenous signals.}, author = {Grones, Peter and Abas, Melinda F and Hajny, Jakub and Jones, Angharad and Waidmann, Sascha and Kleine Vehn, Jürgen and Friml, Jirí}, journal = {Scientific Reports}, number = {1}, publisher = {Springer}, title = {{PID/WAG-mediated phosphorylation of the Arabidopsis PIN3 auxin transporter mediates polarity switches during gravitropism}}, doi = {10.1038/s41598-018-28188-1}, volume = {8}, year = {2018}, } @article{47, abstract = {Plant hormones as signalling molecules play an essential role in the control of plant growth and development. Typically, sites of hormonal action are usually distant from the site of biosynthesis thus relying on efficient transport mechanisms. Over the last decades, molecular identification of proteins and protein complexes involved in hormonal transport has started. Advanced screens for genes involved in hormonal transport in combination with transport assays using heterologous systems such as yeast, insect, or tobacco BY2 cells or Xenopus oocytes provided important insights into mechanisms underlying distribution of hormones in plant body and led to identification of principal transporters for each hormone. This review gives a short overview of the mechanisms of hormonal transport and transporters identified in Arabidopsis thaliana.}, author = {Abualia, Rashed and Benková, Eva and Lacombe, Benoît}, journal = {Advances in Botanical Research}, pages = {115 -- 138}, publisher = {Elsevier}, title = {{Transporters and mechanisms of hormone transport in arabidopsis}}, doi = {10.1016/bs.abr.2018.09.007}, volume = {87}, year = {2018}, } @article{1018, abstract = {In plants, the multistep phosphorelay (MSP) pathway mediates a range of regulatory processes, including those activated by cytokinins. The crosstalk between cytokinin response and light is known for a long time. However, the molecular mechanism underlying the interactionbetween light and cytokinin signaling remains elusive. In the screen for upstream regulators we identified a LONG PALE HYPOCOTYL (LPH) gene whose activity is indispensable for spatiotemporally correct expression of CYTOKININ INDEPENDENT-1 (CKI1), encoding the constitutively active sensor histidine kinase that activates MSP signaling. lph is a new allele of HEME OXYGENASE 1 (HY1) which encodes the key protein in the biosynthesis of phytochromobilin, a cofactor of photoconvertiblephytochromes. Our analysis confirmed the light-dependent regulation oftheCKI1 expression pattern. We show that CKI1 expression is under the control of phytochrome A (phyA), functioning as a dual (both positive and negative) regulator of CKI1 expression, presumably via the phyA-regulated transcription factors PHYTOCHROME INTERACTING FACTOR 3 (PIF3) and CIRCADIAN CLOCK ASSOCIATED 1 (CCA1). Changes in CKI1 expression observed in lph/hy1-7 and phy mutants correlatewithmisregulation of MSP signaling, changedcytokinin sensitivity and developmental aberrations,previously shown to be associated with cytokinin and/or CKI1 action. Besides that, we demonstrate novel role of phyA-dependent CKI1 expression in the hypocotyl elongation and hook development during skotomorphogenesis. Based on these results, we propose that the light-dependent regulation of CKI1 provides a plausible mechanistic link underlying the well-known interaction between light- and cytokinin-controlled plant development.}, author = {Dobisova, Tereza and Hrdinova, Vendula and Cuesta, Candela and Michlickova, Sarka and Urbankova, Ivana and Hejatkova, Romana and Zadnikova, Petra and Pernisová, Markéta and Benková, Eva and Hejátko, Jan}, journal = {Plant Physiology}, number = {1}, pages = {387 -- 404}, publisher = {American Society of Plant Biologists}, title = {{Light regulated expression of sensor histidine kinase CKI1 controls cytokinin related development}}, doi = {10.1104/pp.16.01964}, volume = {174}, year = {2017}, } @article{1004, abstract = {The fundamental tasks of the root system are, besides anchoring, mediating interactions between plant and soil and providing the plant with water and nutrients. The architecture of the root system is controlled by endogenous mechanisms that constantly integrate environmental signals, such as availability of nutrients and water. Extremely important for efficient soil exploitation and survival under less favorable conditions is the developmental flexibility of the root system that is largely determined by its postembryonic branching capacity. Modulation of initiation and outgrowth of lateral roots provides roots with an exceptional plasticity, allows optimal adjustment to underground heterogeneity, and enables effective soil exploitation and use of resources. Here we discuss recent advances in understanding the molecular mechanisms that shape the plant root system and integrate external cues to adapt to the changing environment.}, author = {Ötvös, Krisztina and Benková, Eva}, issn = {0959437X}, journal = {Current Opinion in Genetics & Development}, pages = {82 -- 89}, publisher = {Elsevier}, title = {{Spatiotemporal mechanisms of root branching}}, doi = {10.1016/j.gde.2017.03.010}, volume = {45}, year = {2017}, } @article{946, abstract = {Roots navigate through soil integrating environmental signals to orient their growth. The Arabidopsis root is a widely used model for developmental, physiological and cell biological studies. Live imaging greatly aids these efforts, but the horizontal sample position and continuous root tip displacement present significant difficulties. Here, we develop a confocal microscope setup for vertical sample mounting and integrated directional illumination. We present TipTracker – a custom software for automatic tracking of diverse moving objects usable on various microscope setups. Combined, this enables observation of root tips growing along the natural gravity vector over prolonged periods of time, as well as the ability to induce rapid gravity or light stimulation. We also track migrating cells in the developing zebrafish embryo, demonstrating the utility of this system in the acquisition of high-resolution data sets of dynamic samples. We provide detailed descriptions of the tools enabling the easy implementation on other microscopes.}, author = {Von Wangenheim, Daniel and Hauschild, Robert and Fendrych, Matyas and Barone, Vanessa and Benková, Eva and Friml, Jirí}, journal = {eLife}, publisher = {eLife Sciences Publications}, title = {{Live tracking of moving samples in confocal microscopy for vertically grown roots}}, doi = {10.7554/eLife.26792}, volume = {6}, year = {2017}, } @article{1024, abstract = {The history of auxin and cytokinin biology including the initial discoveries by father–son duo Charles Darwin and Francis Darwin (1880), and Gottlieb Haberlandt (1919) is a beautiful demonstration of unceasing continuity of research. Novel findings are integrated into existing hypotheses and models and deepen our understanding of biological principles. At the same time new questions are triggered and hand to hand with this new methodologies are developed to address these new challenges.}, author = {Hurny, Andrej and Benková, Eva}, issn = {10643745}, journal = {Auxins and Cytokinins in Plant Biology}, pages = {1 -- 29}, publisher = {Springer}, title = {{Methodological advances in auxin and cytokinin biology}}, doi = {10.1007/978-1-4939-6831-2_1}, volume = {1569}, year = {2017}, } @article{1081, abstract = {The asymmetric localization of proteins in the plasma membrane domains of eukaryotic cells is a fundamental manifestation of cell polarity that is central to multicellular organization and developmental patterning. In plants, the mechanisms underlying the polar localization of cargo proteins are still largely unknown and appear to be fundamentally distinct from those operating in mammals. Here, we present a systematic, quantitative comparative analysis of the polar delivery and subcellular localization of proteins that characterize distinct polar plasma membrane domains in plant cells. The combination of microscopic analyses and computational modeling revealed a mechanistic framework common to diverse polar cargos and underlying the establishment and maintenance of apical, basal, and lateral polar domains in plant cells. This mechanism depends on the polar secretion, constitutive endocytic recycling, and restricted lateral diffusion of cargos within the plasma membrane. Moreover, our observations suggest that polar cargo distribution involves the individual protein potential to form clusters within the plasma membrane and interact with the extracellular matrix. Our observations provide insights into the shared cellular mechanisms of polar cargo delivery and polarity maintenance in plant cells.}, author = {Łangowski, Łukasz and Wabnik, Krzysztof T and Li, Hongjiang and Vanneste, Steffen and Naramoto, Satoshi and Tanaka, Hirokazu and Friml, Jirí}, journal = {Cell Discovery}, publisher = {Nature Publishing Group}, title = {{Cellular mechanisms for cargo delivery and polarity maintenance at different polar domains in plant cells}}, doi = {10.1038/celldisc.2016.18}, volume = {2}, year = {2016}, } @article{1153, abstract = {Differential cell growth enables flexible organ bending in the presence of environmental signals such as light or gravity. A prominent example of the developmental processes based on differential cell growth is the formation of the apical hook that protects the fragile shoot apical meristem when it breaks through the soil during germination. Here, we combined in silico and in vivo approaches to identify a minimal mechanism producing auxin gradient-guided differential growth during the establishment of the apical hook in the model plant Arabidopsis thaliana. Computer simulation models based on experimental data demonstrate that asymmetric expression of the PIN-FORMED auxin efflux carrier at the concave (inner) versus convex (outer) side of the hook suffices to establish an auxin maximum in the epidermis at the concave side of the apical hook. Furthermore, we propose a mechanism that translates this maximum into differential growth, and thus curvature, of the apical hook. Through a combination of experimental and in silico computational approaches, we have identified the individual contributions of differential cell elongation and proliferation to defining the apical hook and reveal the role of auxin-ethylene crosstalk in balancing these two processes. © 2016 American Society of Plant Biologists. All rights reserved.}, author = {Žádníková, Petra and Wabnik, Krzysztof T and Abuzeineh, Anas and Gallemí, Marçal and Van Der Straeten, Dominique and Smith, Richard and Inze, Dirk and Friml, Jirí and Prusinkiewicz, Przemysław and Benková, Eva}, journal = {Plant Cell}, number = {10}, pages = {2464 -- 2477}, publisher = {American Society of Plant Biologists}, title = {{A model of differential growth guided apical hook formation in plants}}, doi = {10.1105/tpc.15.00569}, volume = {28}, year = {2016}, } @article{1185, abstract = {The developmental programme of the pistil is under the control of both auxin and cytokinin. Crosstalk between these factors converges on regulation of the auxin carrier PIN-FORMED 1 (PIN1). Here, we show that in the triple transcription factor mutant cytokinin response factor 2 (crf2) crf3 crf6 both pistil length and ovule number were reduced. PIN1 expression was also lower in the triple mutant and the phenotypes could not be rescued by exogenous cytokinin application. pin1 complementation studies using genomic PIN1 constructs showed that the pistil phenotypes were only rescued when the PCRE1 domain, to which CRFs bind, was present. Without this domain, pin mutants resemble the crf2 crf3 crf6 triple mutant, indicating the pivotal role of CRFs in auxin-cytokinin crosstalk.}, author = {Cucinotta, Mara and Manrique, Silvia and Guazzotti, Andrea and Quadrelli, Nadia and Mendes, Marta and Benková, Eva and Colombo, Lucia}, journal = {Development}, number = {23}, pages = {4419 -- 4424}, publisher = {Company of Biologists}, title = {{Cytokinin response factors integrate auxin and cytokinin pathways for female reproductive organ development}}, doi = {10.1242/dev.143545}, volume = {143}, year = {2016}, } @inbook{1210, abstract = {Mechanisms for cell protection are essential for survival of multicellular organisms. In plants, the apical hook, which is transiently formed in darkness when the germinating seedling penetrates towards the soil surface, plays such protective role and shields the vitally important shoot apical meristem and cotyledons from damage. The apical hook is formed by bending of the upper hypocotyl soon after germination, and it is maintained in a closed stage while the hypocotyl continues to penetrate through the soil and rapidly opens when exposed to light in proximity of the soil surface. To uncover the complex molecular network orchestrating this spatiotemporally tightly coordinated process, monitoring of the apical hook development in real time is indispensable. Here we describe an imaging platform that enables high-resolution kinetic analysis of this dynamic developmental process. © Springer Science+Business Media New York 2017.}, author = {Zhu, Qiang and Žádníková, Petra and Smet, Dajo and Van Der Straeten, Dominique and Benková, Eva}, booktitle = {Plant Hormones}, pages = {1 -- 8}, publisher = {Humana Press}, title = {{Real time analysis of the apical hook development}}, doi = {10.1007/978-1-4939-6469-7_1}, volume = {1497}, year = {2016}, } @article{1258, abstract = {When plants grow in close proximity basic resources such as light can become limiting. Under such conditions plants respond to anticipate and/or adapt to the light shortage, a process known as the shade avoidance syndrome (SAS). Following genetic screening using a shade-responsive luciferase reporter line (PHYB:LUC), we identified DRACULA2 (DRA2), which encodes an Arabidopsis homolog of mammalian nucleoporin 98, a component of the nuclear pore complex (NPC). DRA2, together with other nucleoporins, participates positively in the control of the hypocotyl elongation response to plant proximity, a role that can be considered dependent on the nucleocytoplasmic transport of macromolecules (i.e. is transport dependent). In addition, our results reveal a specific role for DRA2 in controlling shade-induced gene expression. We suggest that this novel regulatory role of DRA2 is transport independent and that it might rely on its dynamic localization within and outside of the NPC. These results provide mechanistic insights in to how SAS responses are rapidly established by light conditions. They also indicate that nucleoporins have an active role in plant signaling.}, author = {Gallemi Rovira, Marcal and Galstyan, Anahit and Paulišić, Sandi and Then, Christiane and Ferrández Ayela, Almudena and Lorenzo Orts, Laura and Roig Villanova, Irma and Wang, Xuewen and Micol, José and Ponce, Maria and Devlin, Paul and Martínez García, Jaime}, journal = {Development}, number = {9}, pages = {1623 -- 1631}, publisher = {Company of Biologists}, title = {{DRACULA2 is a dynamic nucleoporin with a role in regulating the shade avoidance syndrome in Arabidopsis}}, doi = {10.1242/dev.130211}, volume = {143}, year = {2016}, } @article{1264, abstract = {n contrast with the wealth of recent reports about the function of μ-adaptins and clathrin adaptor protein (AP) complexes, there is very little information about the motifs that determine the sorting of membrane proteins within clathrin-coated vesicles in plants. Here, we investigated putative sorting signals in the large cytosolic loop of the Arabidopsis (Arabidopsis thaliana) PIN-FORMED1 (PIN1) auxin transporter, which are involved in binding μ-adaptins and thus in PIN1 trafficking and localization. We found that Phe-165 and Tyr-280, Tyr-328, and Tyr-394 are involved in the binding of different μ-adaptins in vitro. However, only Phe-165, which binds μA(μ2)- and μD(μ3)-adaptin, was found to be essential for PIN1 trafficking and localization in vivo. The PIN1:GFP-F165A mutant showed reduced endocytosis but also localized to intracellular structures containing several layers of membranes and endoplasmic reticulum (ER) markers, suggesting that they correspond to ER or ER-derived membranes. While PIN1:GFP localized normally in a μA (μ2)-adaptin mutant, it accumulated in big intracellular structures containing LysoTracker in a μD (μ3)-adaptin mutant, consistent with previous results obtained with mutants of other subunits of the AP-3 complex. Our data suggest that Phe-165, through the binding of μA (μ2)- and μD (μ3)-adaptin, is important for PIN1 endocytosis and for PIN1 trafficking along the secretory pathway, respectively.}, author = {Sancho Andrés, Gloria and Soriano Ortega, Esther and Gao, Caiji and Bernabé Orts, Joan and Narasimhan, Madhumitha and Müller, Anna and Tejos, Ricardo and Jiang, Liwen and Friml, Jirí and Aniento, Fernando and Marcote, Maria}, journal = {Plant Physiology}, number = {3}, pages = {1965 -- 1982}, publisher = {American Society of Plant Biologists}, title = {{Sorting motifs involved in the trafficking and localization of the PIN1 auxin efflux carrier}}, doi = {10.1104/pp.16.00373}, volume = {171}, year = {2016}, } @article{1265, abstract = {Extracellular matrices (ECMs) are central to the advent of multicellular life, and their mechanical propertiesare modulated by and impinge on intracellular signaling pathways that regulate vital cellular functions. High spatial-resolution mapping of mechanical properties in live cells is, however, extremely challenging. Thus, our understanding of how signaling pathways process physiological signals to generate appropriate mechanical responses is limited. We introduce fluorescence emission-Brillouin scattering imaging (FBi), a method for the parallel and all-optical measurements of mechanical properties and fluorescence at the submicrometer scale in living organisms. Using FBi, we showed thatchanges in cellular hydrostatic pressure and cytoplasm viscoelasticity modulate the mechanical signatures of plant ECMs. We further established that the measured "stiffness" of plant ECMs is symmetrically patternedin hypocotyl cells undergoing directional growth. Finally, application of this method to Arabidopsis thaliana with photoreceptor mutants revealed that red and far-red light signals are essential modulators of ECM viscoelasticity. By mapping the viscoelastic signatures of a complex ECM, we provide proof of principlefor the organism-wide applicability of FBi for measuring the mechanical outputs of intracellular signaling pathways. As such, our work has implications for investigations of mechanosignaling pathways and developmental biology.}, author = {Elsayad, Kareem and Werner, Stephanie and Gallemi Rovira, Marcal and Kong, Jixiang and Guajardo, Edmundo and Zhang, Lijuan and Jaillais, Yvon and Greb, Thomas and Belkhadir, Youssef}, journal = {Science Signaling}, number = {435}, publisher = {American Association for the Advancement of Science}, title = {{Mapping the subcellular mechanical properties of live cells in tissues with fluorescence emission-Brillouin imaging}}, doi = {10.1126/scisignal.aaf6326}, volume = {9}, year = {2016}, } @article{1269, abstract = {Plants are continuously exposed to a myriad of external signals such as fluctuating nutrients availability, drought, heat, cold, high salinity, or pathogen/pest attacks that can severely affect their development, growth, and fertility. As sessile organisms, plants must therefore be able to sense and rapidly react to these external inputs, activate efficient responses, and adjust development to changing conditions. In recent years, significant progress has been made towards understanding the molecular mechanisms underlying the intricate and complex communication between plants and the environment. It is now becoming increasingly evident that hormones have an important regulatory role in plant adaptation and defense mechanisms.}, author = {Benková, Eva}, journal = {Plant Molecular Biology}, number = {6}, pages = {597}, publisher = {Springer}, title = {{Plant hormones in interactions with the environment}}, doi = {10.1007/s11103-016-0501-8}, volume = {91}, year = {2016}, } @article{1273, abstract = {Lateral root primordia (LRP) originate from pericycle stem cells located deep within parental root tissues. LRP emerge through overlying root tissues by inducing auxin-dependent cell separation and hydraulic changes in adjacent cells. The auxin-inducible auxin influx carrier LAX3 plays a key role concentrating this signal in cells overlying LRP. Delimiting LAX3 expression to two adjacent cell files overlying new LRP is crucial to ensure that auxin-regulated cell separation occurs solely along their shared walls. Multiscale modeling has predicted that this highly focused pattern of expression requires auxin to sequentially induce auxin efflux and influx carriers PIN3 and LAX3, respectively. Consistent with model predictions, we report that auxin-inducible LAX3 expression is regulated indirectly by AUXIN RESPONSE FACTOR 7 (ARF7). Yeast one-hybrid screens revealed that the LAX3 promoter is bound by the transcription factor LBD29, which is a direct target for regulation by ARF7. Disrupting auxin-inducible LBD29 expression or expressing an LBD29-SRDX transcriptional repressor phenocopied the lax3 mutant, resulting in delayed lateral root emergence. We conclude that sequential LBD29 and LAX3 induction by auxin is required to coordinate cell separation and organ emergence.}, author = {Porco, Silvana and Larrieu, Antoine and Du, Yujuan and Gaudinier, Allison and Goh, Tatsuaki and Swarup, Kamal and Swarup, Ranjan and Kuempers, Britta and Bishopp, Anthony and Lavenus, Julien and Casimiro, Ilda and Hill, Kristine and Benková, Eva and Fukaki, Hidehiro and Brady, Siobhan and Scheres, Ben and Peéet, Benjamin and Bennett, Malcolm}, journal = {Development}, number = {18}, pages = {3340 -- 3349}, publisher = {Company of Biologists}, title = {{Lateral root emergence in Arabidopsis is dependent on transcription factor LBD29 regulation of auxin influx carrier LAX3}}, doi = {10.1242/dev.136283}, volume = {143}, year = {2016}, } @article{1281, abstract = {Plants are able to modulate root growth and development to optimize their nitrogen nutrition. In Arabidopsis (Arabidopsis thaliana), the adaptive root response to nitrate (NO3 -) depends on the NRT1.1/NPF6.3 transporter/sensor. NRT1.1 represses emergence of lateral root primordia (LRPs) at low concentration or absence of NO3 - through its auxin transport activity that lowers auxin accumulation in LR. However, these functional data strongly contrast with the known transcriptional regulation of NRT1.1, which is markedly repressed in LRPs in the absence of NO3 -. To explain this discrepancy, we investigated in detail the spatiotemporal expression pattern of the NRT1.1 protein during LRP development and combined local transcript analysis with the use of transgenic lines expressing tagged NRT1.1 proteins. Our results show that although NO3 - stimulates NRT1.1 transcription and probably mRNA stability both in primary root tissues and in LRPs, it acts differentially on protein accumulation, depending on the tissues considered with stimulation in cortex and epidermis of the primary root and a strong repression in LRPs and to a lower extent at the primary root tip. This demonstrates that NRT1.1 is strongly regulated at the posttranscriptional level by tissue-specific mechanisms. These mechanisms are crucial for controlling the large palette of adaptive responses to NO3 - mediated by NRT1.1 as they ensure that the protein is present in the proper tissue under the specific conditions where it plays a signaling role in this particular tissue.}, author = {Bouguyon, Eléonore and Perrine Walker, Francine and Pervent, Marjorie and Rochette, Juliette and Cuesta, Candela and Benková, Eva and Martinière, Alexandre and Bach, Lien and Krouk, Gabriel and Gojon, Alain and Nacry, Philippe}, journal = {Plant Physiology}, number = {2}, pages = {1237 -- 1248}, publisher = {American Society of Plant Biologists}, title = {{Nitrate controls root development through posttranscriptional regulation of the NRT1.1/NPF6.3 transporter sensor}}, doi = {10.1104/pp.16.01047}, volume = {172}, year = {2016}, } @article{1283, abstract = {The impact of the plant hormone ethylene on seedling development has long been recognized; however, its ecophysiological relevance is unexplored. Three recent studies demonstrate that ethylene is a critical endogenous integrator of various environmental signals including mechanical stress, light, and oxygen availability during seedling germination and growth through the soil.}, author = {Zhu, Qiang and Benková, Eva}, journal = {Trends in Plant Science}, number = {10}, pages = {809 -- 811}, publisher = {Cell Press}, title = {{Seedlings’ strategy to overcome a soil barrier}}, doi = {10.1016/j.tplants.2016.08.003}, volume = {21}, year = {2016}, } @article{1331, abstract = {Cytokinin is a phytohormone that is well known for its roles in numerous plant growth and developmental processes, yet it has also been linked to abiotic stress response in a less defined manner. Arabidopsis (Arabidopsis thaliana) Cytokinin Response Factor 6 (CRF6) is a cytokinin-responsive AP2/ERF-family transcription factor that, through the cytokinin signaling pathway, plays a key role in the inhibition of dark-induced senescence. CRF6 expression is also induced by oxidative stress, and here we show a novel function for CRF6 in relation to oxidative stress and identify downstream transcriptional targets of CRF6 that are repressed in response to oxidative stress. Analysis of transcriptomic changes in wild-type and crf6 mutant plants treated with H2O2 identified CRF6-dependent differentially expressed transcripts, many of which were repressed rather than induced. Moreover, many repressed genes also show decreased expression in 35S:CRF6 overexpressing plants. Together, these findings suggest that CRF6 functions largely as a transcriptional repressor. Interestingly, among the H2O2 repressed CRF6-dependent transcripts was a set of five genes associated with cytokinin processes: (signaling) ARR6, ARR9, ARR11, (biosynthesis) LOG7, and (transport) ABCG14. We have examined mutants of these cytokinin-associated target genes to reveal novel connections to oxidative stress. Further examination of CRF6-DNA interactions indicated that CRF6 may regulate its targets both directly and indirectly. Together, this shows that CRF6 functions during oxidative stress as a negative regulator to control this cytokinin-associated module of CRF6- dependent genes and establishes a novel connection between cytokinin and oxidative stress response.}, author = {Zwack, Paul and De Clercq, Inge and Howton, Timothy and Hallmark, H Tucker and Hurny, Andrej and Keshishian, Erika and Parish, Alyssa and Benková, Eva and Mukhtar, M Shahid and Van Breusegem, Frank and Rashotte, Aaron}, issn = {1532-2548}, journal = {Plant Physiology}, number = {2}, pages = {1249 -- 1258}, publisher = {American Society of Plant Biologists}, title = {{Cytokinin response factor 6 represses cytokinin-associated genes during oxidative stress}}, doi = {10.1104/pp.16.00415}, volume = {172}, year = {2016}, } @article{1492, abstract = {To sustain a lifelong ability to initiate organs, plants retain pools of undifferentiated cells with a preserved prolif eration capacity. The root pericycle represents a unique tissue with conditional meristematic activity, and its tight control determines initiation of lateral organs. Here we show that the meristematic activity of the pericycle is constrained by the interaction with the adjacent endodermis. Release of these restraints by elimination of endo dermal cells by single-cell ablation triggers the pericycle to re-enter the cell cycle. We found that endodermis removal substitutes for the phytohormone auxin-dependent initiation of the pericycle meristematic activity. However, auxin is indispensable to steer the cell division plane orientation of new organ-defining divisions. We propose a dual, spatiotemporally distinct role for auxin during lateral root initiation. In the endodermis, auxin releases constraints arising from cell-to-cell interactions that compromise the pericycle meristematic activity, whereas, in the pericycle, auxin defines the orientation of the cell division plane to initiate lateral roots.}, author = {Marhavy, Peter and Montesinos López, Juan C and Abuzeineh, Anas and Van Damme, Daniël and Vermeer, Joop and Duclercq, Jérôme and Rakusova, Hana and Marhavá, Petra and Friml, Jirí and Geldner, Niko and Benková, Eva}, journal = {Genes and Development}, number = {4}, pages = {471 -- 483}, publisher = {Cold Spring Harbor Laboratory Press}, title = {{Targeted cell elimination reveals an auxin-guided biphasic mode of lateral root initiation}}, doi = {10.1101/gad.276964.115}, volume = {30}, year = {2016}, } @article{1274, abstract = {Synchronized tissue polarization during regeneration or de novo vascular tissue formation is a plant-specific example of intercellular communication and coordinated development. According to the canalization hypothesis, the plant hormone auxin serves as polarizing signal that mediates directional channel formation underlying the spatio-temporal vasculature patterning. A necessary part of canalization is a positive feedback between auxin signaling and polarity of the intercellular auxin flow. The cellular and molecular mechanisms of this process are still poorly understood, not the least, because of a lack of a suitable model system. We show that the main genetic model plant, Arabidopsis (Arabidopsis thaliana) can be used to study the canalization during vascular cambium regeneration and new vasculature formation. We monitored localized auxin responses, directional auxin-transport channels formation, and establishment of new vascular cambium polarity during regenerative processes after stem wounding. The increased auxin response above and around the wound preceded the formation of PIN1 auxin transporter-marked channels from the primarily homogenous tissue and the transient, gradual changes in PIN1 localization preceded the polarity of newly formed vascular tissue. Thus, Arabidopsis is a useful model for studies of coordinated tissue polarization and vasculature formation after wounding allowing for genetic and mechanistic dissection of the canalization hypothesis.}, author = {Mazur, Ewa and Benková, Eva and Friml, Jirí}, journal = {Scientific Reports}, publisher = {Nature Publishing Group}, title = {{Vascular cambium regeneration and vessel formation in wounded inflorescence stems of Arabidopsis}}, doi = {10.1038/srep33754}, volume = {6}, year = {2016}, } @article{1540, abstract = {Plant sexual reproduction involves highly structured and specialized organs: stamens (male) and gynoecia (female, containing ovules). These organs synchronously develop within protective flower buds, until anthesis, via tightly coordinated mechanisms that are essential for effective fertilization and production of viable seeds. The phytohormone auxin is one of the key endogenous signalling molecules controlling initiation and development of these, and other, plant organs. In particular, its uneven distribution, resulting from tightly controlled production, metabolism and directional transport, is an important morphogenic factor. In this review we discuss how developmentally controlled and localized auxin biosynthesis and transport contribute to the coordinated development of plants' reproductive organs, and their fertilized derivatives (embryos) via the regulation of auxin levels and distribution within and around them. Current understanding of the links between de novo local auxin biosynthesis, auxin transport and/or signalling is presented to highlight the importance of the non-cell autonomous action of auxin production on development and morphogenesis of reproductive organs and embryos. An overview of transcription factor families, which spatiotemporally define local auxin production by controlling key auxin biosynthetic enzymes, is also presented.}, author = {Robert, Hélène and Crhák Khaitová, Lucie and Mroue, Souad and Benková, Eva}, journal = {Journal of Experimental Botany}, number = {16}, pages = {5029 -- 5042}, publisher = {Oxford University Press}, title = {{The importance of localized auxin production for morphogenesis of reproductive organs and embryos in Arabidopsis}}, doi = {10.1093/jxb/erv256}, volume = {66}, year = {2015}, } @article{1574, abstract = {Multiple plant developmental processes, such as lateral root development, depend on auxin distribution patterns that are in part generated by the PIN-formed family of auxin-efflux transporters. Here we propose that AUXIN RESPONSE FACTOR7 (ARF7) and the ARF7-regulated FOUR LIPS/MYB124 (FLP) transcription factors jointly form a coherent feed-forward motif that mediates the auxin-responsive PIN3 transcription in planta to steer the early steps of lateral root formation. This regulatory mechanism might endow the PIN3 circuitry with a temporal 'memory' of auxin stimuli, potentially maintaining and enhancing the robustness of the auxin flux directionality during lateral root development. The cooperative action between canonical auxin signalling and other transcription factors might constitute a general mechanism by which transcriptional auxin-sensitivity can be regulated at a tissue-specific level.}, author = {Chen, Qian and Liu, Yang and Maere, Steven and Lee, Eunkyoung and Van Isterdael, Gert and Xie, Zidian and Xuan, Wei and Lucas, Jessica and Vassileva, Valya and Kitakura, Saeko and Marhavy, Peter and Wabnik, Krzysztof T and Geldner, Niko and Benková, Eva and Le, Jie and Fukaki, Hidehiro and Grotewold, Erich and Li, Chuanyou and Friml, Jirí and Sack, Fred and Beeckman, Tom and Vanneste, Steffen}, journal = {Nature Communications}, publisher = {Nature Publishing Group}, title = {{A coherent transcriptional feed-forward motif model for mediating auxin-sensitive PIN3 expression during lateral root development}}, doi = {10.1038/ncomms9821}, volume = {6}, year = {2015}, } @article{1593, abstract = {Plants are sessile organisms that are permanently restricted to their site of germination. To compensate for their lack of mobility, plants evolved unique mechanisms enabling them to rapidly react to ever changing environmental conditions and flexibly adapt their postembryonic developmental program. A prominent demonstration of this developmental plasticity is their ability to bend organs in order to reach the position most optimal for growth and utilization of light, nutrients, and other resources. Shortly after germination, dicotyledonous seedlings form a bended structure, the so-called apical hook, to protect the delicate shoot meristem and cotyledons from damage when penetrating through the soil. Upon perception of a light stimulus, the apical hook rapidly opens and the photomorphogenic developmental program is activated. After germination, plant organs are able to align their growth with the light source and adopt the most favorable orientation through bending, in a process named phototropism. On the other hand, when roots and shoots are diverted from their upright orientation, they immediately detect a change in the gravity vector and bend to maintain a vertical growth direction. Noteworthy, despite the diversity of external stimuli perceived by different plant organs, all plant tropic movements share a common mechanistic basis: differential cell growth. In our review, we will discuss the molecular principles underlying various tropic responses with the focus on mechanisms mediating the perception of external signals, transduction cascades and downstream responses that regulate differential cell growth and consequently, organ bending. In particular, we highlight common and specific features of regulatory pathways in control of the bending of organs and a role for the plant hormone auxin as a key regulatory component.}, author = {Žádníková, Petra and Smet, Dajo and Zhu, Qiang and Van Der Straeten, Dominique and Benková, Eva}, journal = {Frontiers in Plant Science}, number = {4}, publisher = {Frontiers Research Foundation}, title = {{Strategies of seedlings to overcome their sessile nature: Auxin in mobility control}}, doi = {10.3389/fpls.2015.00218}, volume = {6}, year = {2015}, } @article{1640, abstract = {Auxin and cytokinin are key endogenous regulators of plant development. Although cytokinin-mediated modulation of auxin distribution is a developmentally crucial hormonal interaction, its molecular basis is largely unknown. Here we show a direct regulatory link between cytokinin signalling and the auxin transport machinery uncovering a mechanistic framework for cytokinin-auxin cross-talk. We show that the CYTOKININ RESPONSE FACTORS (CRFs), transcription factors downstream of cytokinin perception, transcriptionally control genes encoding PIN-FORMED (PIN) auxin transporters at a specific PIN CYTOKININ RESPONSE ELEMENT (PCRE) domain. Removal of this cis-regulatory element effectively uncouples PIN transcription from the CRF-mediated cytokinin regulation and attenuates plant cytokinin sensitivity. We propose that CRFs represent a missing cross-talk component that fine-tunes auxin transport capacity downstream of cytokinin signalling to control plant development.}, author = {Šimášková, Mária and O'Brien, José and Khan-Djamei, Mamoona and Van Noorden, Giel and Ötvös, Krisztina and Vieten, Anne and De Clercq, Inge and Van Haperen, Johanna and Cuesta, Candela and Hoyerová, Klára and Vanneste, Steffen and Marhavy, Peter and Wabnik, Krzysztof T and Van Breusegem, Frank and Nowack, Moritz and Murphy, Angus and Friml, Jiřĺ and Weijers, Dolf and Beeckman, Tom and Benková, Eva}, journal = {Nature Communications}, publisher = {Nature Publishing Group}, title = {{Cytokinin response factors regulate PIN-FORMED auxin transporters}}, doi = {10.1038/ncomms9717}, volume = {6}, year = {2015}, } @book{10811, abstract = {Auxin is an important signaling compound in plants and vital for plant development and growth. The present book, Auxin and its Role in Plant Development, provides the reader with detailed and comprehensive insight into the functioning of the molecule on the whole and specifically in plant development. In the first part, the functioning, metabolism and signaling pathways of auxin in plants are explained, the second part depicts the specific role of auxin in plant development and the third part describes the interaction and functioning of the signaling compound upon stimuli of the environment. Each chapter is written by international experts in the respective field and designed for scientists and researchers in plant biology, plant development and cell biology to summarize the recent progress in understanding the role of auxin and suggest future perspectives for auxin research.}, editor = {Zažímalová, Eva and Petrášek, Jan and Benková, Eva}, isbn = {9783709115251}, pages = {444}, publisher = {Springer Nature}, title = {{Auxin and Its Role in Plant Development}}, doi = {10.1007/978-3-7091-1526-8}, year = {2014}, } @article{1862, abstract = {The prominent and evolutionarily ancient role of the plant hormone auxin is the regulation of cell expansion. Cell expansion requires ordered arrangement of the cytoskeleton but molecular mechanisms underlying its regulation by signalling molecules including auxin are unknown. Here we show in the model plant Arabidopsis thaliana that in elongating cells exogenous application of auxin or redistribution of endogenous auxin induces very rapid microtubule re-orientation from transverse to longitudinal, coherent with the inhibition of cell expansion. This fast auxin effect requires auxin binding protein 1 (ABP1) and involves a contribution of downstream signalling components such as ROP6 GTPase, ROP-interactive protein RIC1 and the microtubule-severing protein katanin. These components are required for rapid auxin-and ABP1-mediated re-orientation of microtubules to regulate cell elongation in roots and dark-grown hypocotyls as well as asymmetric growth during gravitropic responses.}, author = {Chen, Xu and Grandont, Laurie and Li, Hongjiang and Hauschild, Robert and Paque, Sébastien and Abuzeineh, Anas and Rakusova, Hana and Benková, Eva and Perrot Rechenmann, Catherine and Friml, Jirí}, issn = {1476-4687}, journal = {Nature}, number = {729}, pages = {90 -- 93}, publisher = {Nature Publishing Group}, title = {{Inhibition of cell expansion by rapid ABP1-mediated auxin effect on microtubules}}, doi = {10.1038/nature13889}, volume = {516}, year = {2014}, } @article{1922, abstract = {Germination of Arabidopsis seeds in darkness induces apical hook development, based on a tightly regulated differential growth coordinated by a multiple hormone cross-talk. Here, we endeavoured to clarify the function of brassinosteroids (BRs) and cross-talk with ethylene in hook development. An automated infrared imaging system was developed to study the kinetics of hook development in etiolated Arabidopsis seedlings. To ascertain the photomorphogenic control of hook opening, the system was equipped with an automatic light dimmer. We demonstrate that ethylene and BRs are indispensable for hook formation and maintenance. Ethylene regulation of hook formation functions partly through BRs, with BR feedback inhibition of ethylene action. Conversely, BR-mediated extension of hook maintenance functions partly through ethylene. Furthermore, we revealed that a short light pulse is sufficient to induce rapid hook opening. Our dynamic infrared imaging system allows high-resolution, kinetic imaging of up to 112 seedlings in a single experimental run. At this high throughput, it is ideally suited to rapidly gain insight in pathway networks. We demonstrate that BRs and ethylene cooperatively regulate apical hook development in a phase-dependent manner. Furthermore, we show that light is a predominant regulator of hook opening, inhibiting ethylene- and BR-mediated postponement of hook opening.}, author = {Smet, Dajo and Žádníková, Petra and Vandenbussche, Filip and Benková, Eva and Van Der Straeten, Dominique}, journal = {New Phytologist}, number = {4}, pages = {1398 -- 1411}, publisher = {Wiley-Blackwell}, title = {{Dynamic infrared imaging analysis of apical hook development in Arabidopsis: The case of brassinosteroids}}, doi = {10.1111/nph.12751}, volume = {202}, year = {2014}, } @article{1934, abstract = {The plant hormones auxin and cytokinin mutually coordinate their activities to control various aspects of development [1-9], and their crosstalk occurs at multiple levels [10, 11]. Cytokinin-mediated modulation of auxin transport provides an efficient means to regulate auxin distribution in plant organs. Here, we demonstrate that cytokinin does not merely control the overall auxin flow capacity, but might also act as a polarizing cue and control the auxin stream directionality during plant organogenesis. Cytokinin enhances the PIN-FORMED1 (PIN1) auxin transporter depletion at specific polar domains, thus rearranging the cellular PIN polarities and directly regulating the auxin flow direction. This selective cytokinin sensitivity correlates with the PIN protein phosphorylation degree. PIN1 phosphomimicking mutations, as well as enhanced phosphorylation in plants with modulated activities of PIN-specific kinases and phosphatases, desensitize PIN1 to cytokinin. Our results reveal conceptually novel, cytokinin-driven polarization mechanism that operates in developmental processes involving rapid auxin stream redirection, such as lateral root organogenesis, in which a gradual PIN polarity switch defines the growth axis of the newly formed organ.}, author = {Marhavy, Peter and Duclercq, Jérôme and Weller, Benjamin and Feraru, Elena and Bielach, Agnieszka and Offringa, Remko and Friml, Jirí and Schwechheimer, Claus and Murphy, Angus and Benková, Eva}, journal = {Current Biology}, number = {9}, pages = {1031 -- 1037}, publisher = {Cell Press}, title = {{Cytokinin controls polarity of PIN1-dependent Auxin transport during lateral root organogenesis}}, doi = {10.1016/j.cub.2014.04.002}, volume = {24}, year = {2014}, } @article{2059, abstract = {Plant embryogenesis is regulated by differential distribution of the plant hormone auxin. However, the cells establishing these gradients during microspore embryogenesis remain to be identified. For the first time, we describe, using the DR5 or DR5rev reporter gene systems, the GFP- and GUS-based auxin biosensors to monitor auxin during Brassica napus androgenesis at cellular resolution in the initial stages. Our study provides evidence that the distribution of auxin changes during embryo development and depends on the temperature-inducible in vitro culture conditions. For this, microspores (mcs) were induced to embryogenesis by heat treatment and then subjected to genetic modification via Agrobacterium tumefaciens. The duration of high temperature treatment had a significant influence on auxin distribution in isolated and in vitro-cultured microspores and on microspore-derived embryo development. In the “mild” heat-treated (1 day at 32 °C) mcs, auxin localized in a polar way already at the uni-nucleate microspore, which was critical for the initiation of embryos with suspensor-like structure. Assuming a mean mcs radius of 20 μm, endogenous auxin content in a single cell corresponded to concentration of 1.01 μM. In mcs subjected to a prolonged heat (5 days at 32 °C), although auxin concentration increased dozen times, auxin polarization was set up at a few-celled pro-embryos without suspensor. Those embryos were enclosed in the outer wall called the exine. The exine rupture was accompanied by the auxin gradient polarization. Relative quantitative estimation of auxin, using time-lapse imaging, revealed that primordia possess up to 1.3-fold higher amounts than those found in the root apices of transgenic MDEs in the presence of exogenous auxin. Our results show, for the first time, which concentration of endogenous auxin coincides with the first cell division and how the high temperature interplays with auxin, by what affects delay early establishing microspore polarity. Moreover, we present how the local auxin accumulation demonstrates the apical–basal axis formation of the androgenic embryo and directs the axiality of the adult haploid plant.}, author = {Dubas, Ewa and Moravčíková, Jana and Libantová, Jana and Matušíková, Ildikó and Benková, Eva and Zur, Iwona and Krzewska, Monika}, journal = {Protoplasma}, number = {5}, pages = {1077 -- 1087}, publisher = {Springer}, title = {{The influence of heat stress on auxin distribution in transgenic B napus microspores and microspore derived embryos}}, doi = {10.1007/s00709-014-0616-1}, volume = {251}, year = {2014}, } @article{2227, abstract = {The Balkan Peninsula, characterized by high rates of endemism, is recognised as one of the most diverse and species-rich areas of Europe. However, little is known about the origin of Balkan endemics. The present study addresses the phylogenetic position of the Balkan endemic Ranunculus wettsteinii, as well as its taxonomic status and relationship with the widespread R. parnassiifolius, based on nuclear DNA (internal transcribed spacer, ITS) and plastid regions (rpl32-trnL, rps16-trnQ, trnK-matK and ycf6-psbM). Maximum parsimony and Bayesian inference analyses revealed a well-supported clade formed by accessions of R. wettsteinii. Furthermore, our phylogenetic and network analyses supported previous hypotheses of a likely allopolyploid origin for R. wettsteinii between R. montenegrinus and R. parnassiifolius, with the latter as the maternal parent.}, author = {Cires Rodriguez, Eduardo and Baltisberger, Matthias and Cuesta, Candela and Vargas, Pablo and Prieto, José}, issn = {14396092}, journal = {Organisms Diversity and Evolution}, number = {1}, pages = {1 -- 10}, publisher = {Springer}, title = {{Allopolyploid origin of the Balkan endemic Ranunculus wettsteinii (Ranunculaceae) inferred from nuclear and plastid DNA sequences}}, doi = {10.1007/s13127-013-0150-6}, volume = {14}, year = {2014}, } @article{2472, abstract = {Plant-specific PIN-formed (PIN) efflux transporters for the plant hormone auxin are required for tissue-specific directional auxin transport and cellular auxin homeostasis. The Arabidopsis PIN protein family has been shown to play important roles in developmental processes such as embryogenesis, organogenesis, vascular tissue differentiation, root meristem patterning and tropic growth. Here we analyzed roles of the less characterised Arabidopsis PIN6 auxin transporter. PIN6 is auxin-inducible and is expressed during multiple auxin-regulated developmental processes. Loss of pin6 function interfered with primary root growth and lateral root development. Misexpression of PIN6 affected auxin transport and interfered with auxin homeostasis in other growth processes such as shoot apical dominance, lateral root primordia development, adventitious root formation, root hair outgrowth and root waving. These changes in auxin-regulated growth correlated with a reduction in total auxin transport as well as with an altered activity of DR5-GUS auxin response reporter. Overall, the data indicate that PIN6 regulates auxin homeostasis during plant development.}, author = {Cazzonelli, Christopher and Vanstraelen, Marleen and Simon, Sibu and Yin, Kuide and Carron Arthur, Ashley and Nisar, Nazia and Tarle, Gauri and Cuttriss, Abby and Searle, Iain and Benková, Eva and Mathesius, Ulrike and Masle, Josette and Friml, Jirí and Pogson, Barry}, journal = {PLoS One}, number = {7}, publisher = {Public Library of Science}, title = {{Role of the Arabidopsis PIN6 auxin transporter in auxin homeostasis and auxin-mediated development}}, doi = {10.1371/journal.pone.0070069}, volume = {8}, year = {2013}, } @article{2844, abstract = {As soon as a seed germinates, plant growth relates to gravity to ensure that the root penetrates the soil and the shoot expands aerially. Whereas mechanisms of positive and negative orthogravitropism of primary roots and shoots are relatively well understood [1-3], lateral organs often show more complex growth behavior [4]. Lateral roots (LRs) seemingly suppress positive gravitropic growth and show a defined gravitropic set-point angle (GSA) that allows radial expansion of the root system (plagiotropism) [3, 4]. Despite its eminent importance for root architecture, it so far remains completely unknown how lateral organs partially suppress positive orthogravitropism. Here we show that the phytohormone auxin steers GSA formation and limits positive orthogravitropism in LR. Low and high auxin levels/signaling lead to radial or axial root systems, respectively. At a cellular level, it is the auxin transport-dependent regulation of asymmetric growth in the elongation zone that determines GSA. Our data suggest that strong repression of PIN4/PIN7 and transient PIN3 expression limit auxin redistribution in young LR columella cells. We conclude that PIN activity, by temporally limiting the asymmetric auxin fluxes in the tip of LRs, induces transient, differential growth responses in the elongation zone and, consequently, controls root architecture.}, author = {Rosquete, Michel and Von Wangenheim, Daniel and Marhavy, Peter and Barbez, Elke and Stelzer, Ernst and Benková, Eva and Maizel, Alexis and Kleine Vehn, Jürgen}, journal = {Current Biology}, number = {9}, pages = {817 -- 822}, publisher = {Cell Press}, title = {{An auxin transport mechanism restricts positive orthogravitropism in lateral roots}}, doi = {10.1016/j.cub.2013.03.064}, volume = {23}, year = {2013}, } @article{2880, abstract = {Lateral root (LR) formation is initiated when pericycle cells accumulate auxin, thereby acquiring founder cell (FC) status and triggering asymmetric cell divisions, giving rise to a new primordium. How this auxin maximum in pericycle cells builds up and remains focused is not understood. We report that the endodermis plays an active role in the regulation of auxin accumulation and is instructive for FCs to progress during the LR initiation (LRI) phase. We describe the functional importance of a PIN3 (PIN-formed) auxin efflux carrier-dependent hormone reflux pathway between overlaying endodermal and pericycle FCs. Disrupting this reflux pathway causes dramatic defects in the progress of FCs towards the next initiation phase. Our data identify an unexpected regulatory function for the endodermis in LRI as part of the fine-tuning mechanism that appears to act as a check point in LR organogenesis after FCs are specified.}, author = {Marhavy, Peter and Vanstraelen, Marleen and De Rybel, Bert and Zhaojun, Ding and Bennett, Malcolm and Beeckman, Tom and Benková, Eva}, journal = {EMBO Journal}, number = {1}, pages = {149 -- 158}, publisher = {Wiley-Blackwell}, title = {{Auxin reflux between the endodermis and pericycle promotes lateral root initiation}}, doi = {10.1038/emboj.2012.303}, volume = {32}, year = {2013}, } @article{527, abstract = {The apical-basal axis of the early plant embryo determines the body plan of the adult organism. To establish a polarized embryonic axis, plants evolved a unique mechanism that involves directional, cell-to-cell transport of the growth regulator auxin. Auxin transport relies on PIN auxin transporters [1], whose polar subcellular localization determines the flow directionality. PIN-mediated auxin transport mediates the spatial and temporal activity of the auxin response machinery [2-7] that contributes to embryo patterning processes, including establishment of the apical (shoot) and basal (root) embryo poles [8]. However, little is known of upstream mechanisms guiding the (re)polarization of auxin fluxes during embryogenesis [9]. Here, we developed a model of plant embryogenesis that correctly generates emergent cell polarities and auxin-mediated sequential initiation of apical-basal axis of plant embryo. The model relies on two precisely localized auxin sources and a feedback between auxin and the polar, subcellular PIN transporter localization. Simulations reproduced PIN polarity and auxin distribution, as well as previously unknown polarization events during early embryogenesis. The spectrum of validated model predictions suggests that our model corresponds to a minimal mechanistic framework for initiation and orientation of the apical-basal axis to guide both embryonic and postembryonic plant development.}, author = {Wabnik, Krzysztof T and Robert, Hélène and Smith, Richard and Friml, Jirí}, journal = {Current Biology}, number = {24}, pages = {2513 -- 2518}, publisher = {Cell Press}, title = {{Modeling framework for the establishment of the apical-basal embryonic axis in plants}}, doi = {10.1016/j.cub.2013.10.038}, volume = {23}, year = {2013}, } @article{827, abstract = {As sessile organisms, plants have to be able to adapt to a continuously changing environment. Plants that perceive some of these changes as stress signals activate signaling pathways to modulate their development and to enable them to survive. The complex responses to environmental cues are to a large extent mediated by plant hormones that together orchestrate the final plant response. The phytohormone cytokinin is involved in many plant developmental processes. Recently, it has been established that cytokinin plays an important role in stress responses, but does not act alone. Indeed, the hormonal control of plant development and stress adaptation is the outcome of a complex network of multiple synergistic and antagonistic interactions between various hormones. Here, we review the recent findings on the cytokinin function as part of this hormonal network. We focus on the importance of the crosstalk between cytokinin and other hormones, such as abscisic acid, jasmonate, salicylic acid, ethylene, and auxin in the modulation of plant development and stress adaptation. Finally, the impact of the current research in the biotechnological industry will be discussed.}, author = {O'Brien, José and Benková, Eva}, journal = {Frontiers in Plant Science}, publisher = {Frontiers Research Foundation}, title = {{Cytokinin cross talking during biotic and abiotic stress responses}}, doi = {10.3389/fpls.2013.00451}, volume = {4}, year = {2013}, } @article{828, abstract = {The plant root system is essential for providing anchorage to the soil, supplying minerals and water, and synthesizing metabolites. It is a dynamic organ modulated by external cues such as environmental signals, water and nutrients availability, salinity and others. Lateral roots (LRs) are initiated from the primary root post-embryonically, after which they progress through discrete developmental stages which can be independently controlled, providing a high level of plasticity during root system formation. Within this review, main contributions are presented, from the classical forward genetic screens to the more recent high-throughput approaches, combined with computer model predictions, dissecting how LRs and thereby root system architecture is established and developed.}, author = {Cuesta, Candela and Wabnik, Krzysztof T and Benková, Eva}, journal = {Frontiers in Plant Science}, publisher = {Frontiers Research Foundation}, title = {{Systems approaches to study root architecture dynamics}}, doi = {10.3389/fpls.2013.00537}, volume = {4}, year = {2013}, }