Department of Plant Biology, Cornell University, Ithaca, New York, United States of America.
PLoS One. 2014 Jun 19;9(6):e100347. doi: 10.1371/journal.pone.0100347. eCollection 2014.
The impact of cell cycle on plant immunity was indicated by the enhancement of disease resistance with overexpressing OSD1 and UVI4 genes that are negative regulators of cell cycle controller APC (anaphase promoting complex). CPR5 is another gene that is implicated in cell cycle regulation and plant immunity, but its mode of action is not known. Here we report the analysis of genetic requirement for the function of UVI4 and OSD1 in cell cycle progression control and in particular the involvement of CPR5 in this regulation. We show that the APC activator CCS52A1 partially mediates the function of OSD1 and UVI4 in female gametophyte development. We found that the cpr5 mutation suppresses the endoreduplication defect in the uvi4 single mutant and partially rescued the gametophyte development defect in the osd1 uvi4 double mutant while the uvi4 mutation enhances the cpr5 defects in trichome branching and plant disease resistance. In addition, cyclin B1 genes CYCB1;1, CYCB1;2, and CYCB1;4 are upregulated in cpr5. Therefore, CPR5 has a large role in cell cycle regulation and this role has a complex interaction with that of UVI4 and OSD1. This study further indicates an intrinsic link between plant defense responses and cell cycle progression.
细胞周期对植物免疫的影响表现在过表达 OSD1 和 UVI4 基因上，这两个基因是细胞周期控制器 APC（有丝分裂促进复合物）的负调控因子。CPR5 是另一个与细胞周期调控和植物免疫有关的基因，但它的作用机制尚不清楚。在这里，我们报告了 UVI4 和 OSD1 在细胞周期进程控制中的功能的遗传需求分析，特别是 CPR5 在这种调节中的参与。我们表明，APC 激活剂 CCS52A1 部分介导了 OSD1 和 UVI4 在雌性配子体发育中的功能。我们发现，cpr5 突变抑制了 uvi4 单突变体中的内复制缺陷，并部分挽救了 osd1 uvi4 双突变体中的配子体发育缺陷，而 uvi4 突变增强了 cpr5 在毛状体分支和植物抗病性方面的缺陷。此外，cyclin B1 基因 CYCB1;1、CYCB1;2 和 CYCB1;4 在 cpr5 中上调。因此，CPR5 在细胞周期调控中起着重要作用，其作用与 UVI4 和 OSD1 之间存在复杂的相互作用。这项研究进一步表明植物防御反应与细胞周期进程之间存在内在联系。
