TY - JOUR AU - Friml, Jirí AU - Benfey, Philip AU - Benková, Eva AU - Bennett, Malcolm AU - Berleth, Thomas AU - Geldner, Niko AU - Grebe, Markus AU - Heisler, Marcus AU - Hejátko, Jan AU - Jürgens, Gerd AU - Laux, Thomas AU - Lindsey, Keith AU - Lukowitz, Wolfgang AU - Luschnig, Christian AU - Offringa, Remko AU - Scheres, Ben AU - Swarup, Ranjan AU - Torres Ruiz, Ramón AU - Weijers, Dolf AU - Zažímalová, Eva ID - 3005 IS - 1 JF - Trends in Plant Science TI - Apical-basal polarity: Why plant cells don't stand on their heads VL - 11 ER - TY - JOUR AB - Plants and some animals have a profound capacity to regenerate organs from adult tissues. Molecular mechanisms for regeneration have, however, been largely unexplored. Here we investigate a local regeneration response in Arabidopsis roots. Laser-induced wounding disrupts the flow of auxin-a cell-fate-instructive plant hormone-in root tips, and we demonstrate that resulting cell-fate changes require the PLETHORA, SHORTROOT, and SCARECROW transcription factors. These transcription factors regulate the expression and polar position of PIN auxin efflux-facilitating membrane proteins to reconstitute auxin transport in renewed root tips. Thus, a regeneration mechanism using embryonic root stem-cell patterning factors first responds to and subsequently stabilizes a new hormone distribution. AU - Xu, Jian AU - Hofhuis, Hugo AU - Heidstra, Renze AU - Sauer, Michael AU - Jirí Friml AU - Scheres, Ben ID - 3008 IS - 5759 JF - Science TI - A molecular framework for plant regeneration VL - 311 ER - TY - JOUR AU - Paciorek, Tomasz AU - Friml, Jirí ID - 3009 IS - 7 JF - Journal of Cell Science TI - Auxin signaling VL - 119 ER - TY - JOUR AB - Plant development is characterized by a profound ability to regenerate and form tissues with new axes of polarity. An unsolved question concerns how the position within a tissue and cues from neighboring cells are integrated to specify the polarity of individual cells. The canalization hypothesis proposes a feedback effect of the phytohormone auxin on the directionality of intercellular auxin flow as a means to polarize tissues. Here we identify a cellular and molecular mechanism for canalization. Local auxin application, wounding, or auxin accumulation during de novo organ formation lead to rearrangements in the subcellular polar localization of PIN auxin transport components. This auxin effect on PIN polarity is cell-specific, does not depend on PIN transcription, and involves the Aux/IAA-ARF (indole-3-acetic acid-auxin response factor) signaling pathway. Our data suggest that auxin acts as polarizing cue, which links individual cell polarity with tissue and organ polarity through control of PIN polar targeting. This feedback regulation provides a conceptual framework for polarization during multiple regenerative and patterning processes in plants. AU - Sauer, Michael AU - Balla, Jozef AU - Luschnig, Christian AU - Wiśniewska, Justyna AU - Reinöhl, Vilém AU - Friml, Jirí AU - Benková, Eva ID - 3016 IS - 20 JF - Genes and Development TI - Canalization of auxin flow by Aux/IAA-ARF-dependent feedback regulation of PIN polarity VL - 20 ER - TY - JOUR AB - The plant hormone auxin plays crucial roles in regulating plant growth development, including embryo and root patterning, organ formation, vascular tissue differentiation and growth responses to environmental stimuli. Asymmetric auxin distribution patterns have been observed within tissues, and these so-called auxin gradients change dynamically during different developmental processes. Most auxin is synthesized in the shoot and distributed directionally throughout the plant. This polar auxin transport is mediated by auxin influx and efflux facilitators, whose subcellular polar localizations guide the direction of auxin flow. The polar localization of PIN auxin efflux carriers changes in response to developmental and external cues in order to channel auxin flow in a regulated manner for organized growth. Auxin itself modulates the expression and subcellular localization of PIN proteins, contributing to a complex pattern of feedback regulation. Here we review the available information mainly from studies of a model plant, Arabidopsis thaliana, on the generation of auxin gradients, the regulation of polar auxin transport and further downstream cellular events. AU - Tanaka, Hirokazu AU - Dhonukshe, Pankaj AU - Brewer, Philip AU - Friml, Jirí ID - 3017 IS - 23 JF - Cellular and Molecular Life Sciences TI - Spatiotemporal asymmetric auxin distribution: A means to coordinate plant development VL - 63 ER -