Walia Ankit, Carter Ross, Wightman Raymond, Meyerowitz Elliot M, Jönsson Henrik, Jones Alexander M
Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, UK.
Sainsbury Laboratory, University of Cambridge, Cambridge CB2 1LR, UK; Howard Hughes Medical Institute and Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
Dev Cell. 2024 Dec 16;59(24):3245-3258.e3. doi: 10.1016/j.devcel.2024.09.021. Epub 2024 Oct 7.
Differential growth is central to eukaryotic morphogenesis. We showed using cellular imaging, simulations, and perturbations that light-induced differential growth in a curved organ, the Arabidopsis thaliana apical hook, emerges from the longitudinal expansion of subepidermal cells, acting in parallel with a differential in the material properties of epidermal cell walls that resist expansion. The greater expansion of inner hook cells that results in apical hook opening is gated by wall alkalinity and auxin, both of which are depleted upon illumination. We further identified mechanochemical feedback from wall mechanics to light stimulated auxin depletion, which may contribute to gating hook opening under mechanical restraint. These results highlight how plant cells coordinate growth among tissue layers by linking mechanics and hormonal gradients with the cell wall remodeling required for differential growth.
差异生长是真核生物形态发生的核心。我们通过细胞成像、模拟和扰动实验表明，在弯曲器官拟南芥顶端弯钩中，光诱导的差异生长源于表皮下细胞的纵向扩张，同时伴随着抵抗扩张的表皮细胞壁材料特性的差异。内部弯钩细胞的更大扩张导致顶端弯钩打开，这一过程受细胞壁碱度和生长素的调控，光照会使二者消耗殆尽。我们进一步确定了从细胞壁力学到光刺激生长素消耗的机械化学反馈，这可能有助于在机械约束下控制弯钩打开。这些结果突出了植物细胞如何通过将力学和激素梯度与差异生长所需的细胞壁重塑联系起来，协调组织层间的生长。
