Two mechanisms regulate directional cell growth in Arabidopsis lateral roots

eLife

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[1] Department of Engineering Science, University of Oxford, Oxford, United Kingdom;Department of Engineering Science, University of Oxford, Oxford, United Kingdom;Department of Continuum Mechanics and Structural Analysis, University Carlos III of Madrid, Madrid, Spain;Department of Plant Sciences, University of Oxford, Oxford, United Kingdom;

关键词: directional growth;    cell edges;    plant morphogenesis;    anisotropy;    Rab GTPase;    cytoskeleton;    A. thaliana;   

DOI  :  10.7554/eLife.47988

来源: publisher

【 摘 要 】

10.7554/eLife.47988.001Morphogenesis in plants depends critically on directional (anisotropic) growth. This occurs principally perpendicular to the net orientation of cellulose microfibrils (CMFs), which is in turn controlled by cortical microtubules (CMTs). In young lateral roots of Arabidopsis thaliana, growth anisotropy also depends on RAB-A5c, a plant-specific small GTPase that specifies a membrane trafficking pathway to the geometric edges of cells. Here we investigate the functional relationship between structural anisotropy at faces and RAB-A5c activity at edges during lateral root development. We show that surprisingly, inhibition of RAB-A5c function is associated with increased CMT/CMF anisotropy. We present genetic, pharmacological, and modelling evidence that this increase in CMT/CMF anisotropy partially compensates for loss of an independent RAB-A5c-mediated mechanism that maintains anisotropic growth in meristematic cells. We show that RAB-A5c associates with CMTs at cell edges, indicating that CMTs act as an integration point for both mechanisms controlling cellular growth anisotropy in lateral roots.

【 授权许可】

CC BY