Tian Peng, Liu Jiafan, Yan Baohui, Li Shuai, Lei Bin, Shen Rongxin, Lei Cailin, Xu Miaoyun
Biotechnology Research Institute, Chinese Academy of Agriculture Sciences, Beijing 100081, China.
College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China.
Plants (Basel). 2022 Jun 16;11(12):1586. doi: 10.3390/plants11121586.
Brassinosteroids (BRs) are a crucial class of plant hormones that regulate many important agronomic traits in rice ( L.); thus, the BR signaling pathway is a very important tool for breeders to improve the grain yield and quantity of rice. Contrary to the well-established BR signaling pathway in , there are significant gaps in the rice BR signaling pathway, especially the regulation mechanism from OsBSK3 to OsPPKLs and OsGSKs. In this study, we report how knockout mutants confer shorter and lighter grains and exhibit a typical BR-insensitive phenotype, suggesting plays a positive role in BR signaling without genetic redundancy with homologs. Furthermore, OsBSK3 could physically interact with OsPPKL1 and OsGSK3, the downstream components in BR signaling, as a scaffold protein, and inhibit the phosphatase activity of OsPPKL1 on the dephosphorylation of OsGSK3. In addition, the genetic evidence showed acts upstream of in regulating grain length and weight. Our results clarify the role of and provide new insights into BR-signaling mechanisms, leading to potential new targets for the genetic improvement of rice.
油菜素甾醇（BRs）是一类关键的植物激素，可调控水稻（Oryza sativa L.）的许多重要农艺性状；因此，BR信号通路是育种者提高水稻产量和品质的重要工具。与模式植物中已明确的BR信号通路不同，水稻BR信号通路存在显著空白，尤其是从OsBSK3到OsPPKLs和OsGSKs的调控机制。在本研究中，我们报道了[基因名称]敲除突变体如何导致谷粒更短、更轻，并表现出典型的BR不敏感表型，表明[基因名称]在BR信号传导中起正向作用，且与同源基因无遗传冗余。此外，OsBSK3可作为支架蛋白与BR信号下游组分OsPPKL1和OsGSK3发生物理相互作用，并抑制OsPPKL1对OsGSK3去磷酸化的磷酸酶活性。此外，遗传学证据表明[基因名称]在调控粒长和粒重方面作用于[另一基因名称]的上游。我们的结果阐明了[基因名称]的作用，并为BR信号传导机制提供了新见解，为水稻遗传改良带来了潜在的新靶点。
