Wang Ningna, Shi Yiyuan, Jiang Qun, Li Huan, Fan Wenxia, Feng Yu, Li Li, Liu Bin, Lin Feng, Jing Wen, Zhang Wenhua, Shen Like
Department of Plant Biology, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Life Sciences, Nanjing Agricultural University, Nanjing, China.
Guangdong Key Laboratory of New Technology in Rice Breeding, Rice Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China.
Plant Cell Environ. 2023 Apr;46(4):1232-1248. doi: 10.1111/pce.14520. Epub 2023 Jan 4.
The phosphatidylinositol-specific phospholipase Cs (PI-PLCs) catalyze the hydrolysis of phosphatidylinositols, which play crucial roles in signaling transduction during plant development and stress response. However, the regulation of PI-PLC is still poorly understood. A previous study showed that a rice PI-PLC, OsPLC1, was essential to rice salt tolerance. Here, we identified a 14-3-3 protein, OsGF14b, as an interaction partner of OsPLC1. Similar to OsPLC1, OsGF14b also positively regulates rice salt tolerance, and their interaction can be promoted by NaCl stress. OsGF14b also positively regulated the hydrolysis activity of OsPLC1, and is essential to NaCl-induced activation of rice PI-PLCs. We further discovered that OsPLC1 was degraded via ubiquitin-proteasome pathway, and OsGF14b could inhibit the ubiquitination of OsPLC1 to protect OsPLC1 from degradation. Under salt stress, the OsPLC1 protein level in osgf14b was lower than the corresponding value of WT, whereas overexpression of OsGF14b results in a significant increase of OsPLC1 stability. Taken together, we propose that OsGF14b can interact with OsPLC1 and promote its activity and stability, thereby improving rice salt tolerance. This study provides novel insights into the important roles of 14-3-3 proteins in regulating protein stability and function in response to salt stress.
磷脂酰肌醇特异性磷脂酶C（PI-PLCs）催化磷脂酰肌醇的水解，磷脂酰肌醇在植物发育和应激反应的信号转导中起关键作用。然而，PI-PLC的调控机制仍知之甚少。先前的一项研究表明，水稻PI-PLC，即OsPLC1，对水稻耐盐性至关重要。在此，我们鉴定出一种14-3-3蛋白，即OsGF14b，作为OsPLC1的相互作用伙伴。与OsPLC1相似，OsGF14b也正向调控水稻耐盐性，并且它们的相互作用可被NaCl胁迫促进。OsGF14b还正向调控OsPLC1的水解活性，并且对NaCl诱导的水稻PI-PLCs激活至关重要。我们进一步发现，OsPLC1通过泛素-蛋白酶体途径降解，而OsGF14b可以抑制OsPLC1的泛素化，从而保护OsPLC1不被降解。在盐胁迫下，osgf14b中OsPLC1的蛋白水平低于野生型的相应值，而OsGF14b的过表达导致OsPLC1稳定性显著增加。综上所述，我们提出OsGF14b可以与OsPLC1相互作用并促进其活性和稳定性，从而提高水稻耐盐性。本研究为14-3-3蛋白在响应盐胁迫调节蛋白质稳定性和功能中的重要作用提供了新的见解。
