Xie Yonghong, Fan Zhupeng, Teng Kaichong, Huang Zejian, Xu Kaizun, Li Jianxiong
State Key Laboratory for Conservation and Utilization of Subtropical Agri-Bioresources, College of Agriculture, Guangxi University, Nanning, 530004, China.
Guangxi Key Laboratory of Agro-Environment and Agric-Products Safety, College of Agriculture, Guangxi University, Nanning, 530004, China.
Rice (N Y). 2025 Aug 2;18(1):74. doi: 10.1186/s12284-025-00831-2.
Brassinosteroids (BRs) and gibberellins (GAs) are two important phytohormones that regulate plant growth and development. Crosstalk between BR and GA has been unveiled in Arabidopsis but the molecular mechanism by which the concurrence of these two signaling pathways regulates plant growth and development in rice remains elusive. The14-3-3 proteins are a family of conserved molecules that interact with a number of protein clients to regulate fundamental cellular processes including different aspects of plant hormone physiology. Here, we report that the rice 14-3-3 protein OsGF14h (G-box factor 14-3-3 homolog h) negatively modulates BR response and positively regulates GA signaling in rice. Overexpressing OsGF14h in rice increased plant height and grain yield, whereas knocking out OsGF14h increased lamina joint angle and reduced plant height and grain yield. OsGF14h interacted with both OsOFP8, a positive regulator in BR signaling, and SLR1, a negative key regulator in GA signaling. Interaction with OsGF14h led to nuclear export and cytoplasmic retention of OsOFP8, whereas OsGF14h interaction resulted in SLR1 shuttling from the nucleus to the cytoplasm and consequently inducing degradation of SLR1. Our results indicate that OsGF14h functions in both BR and GA signaling pathways and acts as a crosstalk point for BR and GA signaling, which offers new insights into the role of 14-3-3 proteins in regulating plant growth and development by modulating BR and GA signaling crosstalk.
油菜素甾醇（BRs）和赤霉素（GAs）是两种重要的植物激素，可调节植物的生长和发育。拟南芥中已揭示了BR和GA之间的相互作用，但这两条信号通路的协同作用如何调控水稻的生长和发育，其分子机制仍不清楚。14-3-3蛋白是一类保守分子，可与许多蛋白质相互作用，调节包括植物激素生理学不同方面在内的基本细胞过程。在此，我们报道水稻14-3-3蛋白OsGF14h（G-box因子14-3-3同源蛋白h）对水稻的BR反应起负调控作用，对GA信号起正调控作用。在水稻中过表达OsGF14h可增加株高和籽粒产量，而敲除OsGF14h则增加叶片夹角并降低株高和籽粒产量。OsGF14h与BR信号的正调控因子OsOFP8以及GA信号的负关键调控因子SLR1均相互作用。与OsGF14h相互作用导致OsOFP8从细胞核输出并滞留在细胞质中，而OsGF14h相互作用导致SLR1从细胞核穿梭到细胞质，从而诱导SLR1降解。我们的结果表明，OsGF14h在BR和GA信号通路中均起作用，并作为BR和GA信号的一个相互作用点，这为14-3-3蛋白通过调节BR和GA信号相互作用来调控植物生长和发育的作用提供了新的见解。
