Microtubule-Mediated Wall Anisotropy Contributes to Leaf Blade Flattening.
Feng Zhao, Fei Du, Hadrien Oliveri, Lüwen Zhou, Olivier Ali, Wenqian Chen, Shiliang Feng, Qingqing Wang, Shouqin Lü, Mian Long, René Schneider, Arun Sampathkumar, Christophe Godin, Jan Traas, Yuling Jiao
Current Biology: CB, 30 (1-14) (2020)
Plant organs can adopt a wide range of shapes, resulting from highly directional cell growth and divisions. We focus here on leaves and leaf-like organs in Arabidopsis and tomato, characterized by the formation of thin, flat laminae. Combining experimental approaches with 3D mechanical modeling, we provide evidence that leaf shape depends on cortical microtubule mediated cellulose deposition along the main predicted stress orientations, in particular, along the adaxial-abaxial axis in internal cell walls. This behavior can be explained by a mechanical feedback and has the potential to sustain and even amplify a preexisting degree of flatness, which in turn depends on genes involved in the control of organ polarity and leaf margin formation.