GEF14 acts as a specific activator of the plant osmotic signaling pathway by controlling ROP6 nanodomain formation

作者：Lucille Gorgues, Marija Smokvarska, Caroline Mercier, Clara Paola Igisch, Amandine Crabos, Armelle Dongois, Vincent Bayle, Jean-Bernard Fiche, Philippe Nacry, Marcelo Nöllmann, Yvon Jaillais, Alexandre Martinière · 发表于：EMBO Reports · 年份：2025 · DOI：10.1038/s44319-025-00412-w · 被引用次数：7 · 研究领域：Plant Stress Responses and Tolerance、Plant Molecular Biology Research、Plant Reproductive Biology

During their growth, plants encounter and respond to a variety of environmental signals. However, the mechanisms underlying the integration and specificity of signals remain poorly understood. Rho of Plant (ROP) signaling plays a central role in various processes, including polar cell growth and responses to different stimuli, and relies on stimuli-dependent membrane nanodomains. The effector composition of ROP6 nanodomains varies depending on the signal and may be involved in downstream signal specificity. In this study, we explore how ROP6 signaling is regulated by Guanine nucleotide Exchange Factor (GEF) during osmotic stress. We find that GEF14 is required for osmotically induced ROS accumulation. This isoform acts specifically in response to osmotic stimulation, since it is dispensable for other stimuli. We demonstrate that GEF14 activates ROP6 and controls its clustering in a signal-specific manner. Furthermore, we find that GEF14 relocates from the cytoplasm to clusters at the plasma membrane after osmotic stimulation. Together, our results suggest that a single GEF isoform can encode for signal specificity controlling ROP6 activation, clustering and downstream cellular responses.