TY - THES AB - 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. AU - Artner, Christina ID - 11879 KW - high ambient temperature KW - auxin KW - PINs KW - Zinc-Finger proteins KW - thermomorphogenesis KW - stress SN - 2663-337X TI - Modulation of auxin transport via ZF proteins adjust plant response to high ambient temperature ER - TY - JOUR AB - 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. AU - Cavallari, Nicola AU - Artner, Christina AU - Benková, Eva ID - 9212 IS - 7 JF - Cold Spring Harbor Perspectives in Biology SN - 1943-0264 TI - Auxin-regulated lateral root organogenesis VL - 13 ER - TY - JOUR AB - 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. AU - Ötvös, Krisztina AU - Marconi, Marco AU - Vega, Andrea AU - O’Brien, Jose AU - Johnson, Alexander J AU - Abualia, Rashed AU - Antonielli, Livio AU - Montesinos López, Juan C AU - Zhang, Yuzhou AU - Tan, Shutang AU - Cuesta, Candela AU - Artner, Christina AU - Bouguyon, Eleonore AU - Gojon, Alain AU - Friml, Jiří AU - Gutiérrez, Rodrigo A. AU - Wabnik, Krzysztof T AU - Benková, Eva ID - 9010 IS - 3 JF - EMBO Journal SN - 02614189 TI - Modulation of plant root growth by nitrogen source-defined regulation of polar auxin transport VL - 40 ER - TY - GEN AB - The main idea behind the Core Project is to teach first year students at IST scientific communication skills and let them practice by presenting their research within an interdisciplinary environment. Over the course of the first semester, students participated in seminars, where they shared their results with the colleagues from other fields and took part in discussions on relevant subjects. The main focus during this sessions was on delivering the information in a simplified and comprehensible way, going into the very basics of a subject if necessary. At the end, the students were asked to present their research in the written form to exercise their writing skills. The reports were gathered in this document. All of them were reviewed by the teaching assistants and write-ups illustrating unique stylistic features and, in general, an outstanding level of writing skills, were honorably mentioned in the section "Selected Reports". AU - Maslov, Mikhail AU - Kondrashov, Fyodor AU - Artner, Christina AU - Hennessey-Wesen, Mike AU - Kavcic, Bor AU - Machnik, Nick N AU - Satapathy, Roshan K AU - Tomanek, Isabella ID - 8151 TI - Core Project Proceedings ER - TY - JOUR AB - 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. AU - Moulinier-Anzola, Jeanette AU - Schwihla, Maximilian AU - De-Araújo, Lucinda AU - Artner, Christina AU - Jörg, Lisa AU - Konstantinova, Nataliia AU - Luschnig, Christian AU - Korbei, Barbara ID - 15037 IS - 5 JF - Molecular Plant KW - Plant Science KW - Molecular Biology SN - 1674-2052 TI - TOLs function as ubiquitin receptors in the early steps of the ESCRT pathway in higher plants VL - 13 ER - TY - JOUR AU - Artner, Christina AU - Benková, Eva ID - 6920 IS - 10 JF - Molecular Plant SN - 1674-2052 TI - Ethylene and cytokinin - partners in root growth regulation VL - 12 ER -