Hunan Provincial Engineering Research Centre of Lily Germplasm Resource Innovation and Deep Processing, College of Life Sciences and Chemistry, Hunan University of Technology, Zhuzhou 412007, Hunan, China.
College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China.
Proc Natl Acad Sci U S A. 2022 Nov 22;119(47):e2117803119. doi: 10.1073/pnas.2117803119. Epub 2022 Nov 14.
The formation of cell polarity is essential for many developmental processes such as polar cell growth and spatial patterning of cell division. A plant-specific ROP (h-like GTPases from lants) subfamily of conserved Rho GTPase plays a crucial role in the regulation of cell polarity. However, the functional study of ROPs in angiosperm is challenging because of their functional redundancy. The genome encodes a single gene, Mp, providing an excellent genetic system to study ROP-dependent signaling pathways. Mp knockout mutants exhibited rhizoid growth defects, and MpROP was localized at the tip of elongating rhizoids, establishing a role for MpROP in the control of polar cell growth and its functional conservation in plants. Furthermore, the Mp knockout mutant showed defects in the formation of meristem notches associated with disorganized cell division patterns. These results reveal a critical function of Mp in the regulation of plant development. Interestingly, these phenotypes were complemented not only by Mp but also At, supporting the conservation of ROP's function among land plants. Our results demonstrate a great potential for as a powerful genetic system for functional and mechanistic elucidation of ROP signaling pathways during plant development.
细胞极性的形成对于许多发育过程至关重要，例如极性细胞的生长和细胞分裂的空间模式。植物特异性 ROP（来自植物的 h 样 GTPases）保守 Rho GTPase 亚家族在调节细胞极性方面发挥着关键作用。然而，由于其功能冗余，被子植物中 ROP 的功能研究具有挑战性。基因组编码单个基因 Mp，为研究 ROP 依赖性信号通路提供了一个极好的遗传系统。Mp 敲除突变体表现出根状生长缺陷，并且 MpROP 定位于伸长的根状突起的尖端，这确立了 MpROP 在控制极性细胞生长及其在植物中的功能保守性中的作用。此外，Mp 敲除突变体在与细胞分裂模式紊乱相关的分生组织切口中显示出缺陷。这些结果揭示了 Mp 在调节植物发育中的关键功能。有趣的是，这些表型不仅可以被 Mp 互补，也可以被 At 互补，支持 ROP 功能在陆地植物中的保守性。我们的结果表明，在植物发育过程中，作为功能和机制阐明 ROP 信号通路的强大遗传系统，具有巨大的潜力。
