Analysis of sulfide signaling in rice highlights specific drought responses

Hydrogen sulfide regulates essential plant processes, including adaptation responses to stress situations, and the best characterized mechanism of action of sulfide consists of the post-translational modification of persulfidation. In this study, we reveal the first persulfidation proteome described in rice including 3443 different persulfidated proteins that participate in a broad range of biological processes and metabolic pathways. In addition, comparative proteomics revealed specific proteins involved in sulfide signaling during drought responses. Several proteins are involved in the maintenance of cellular redox homeostasis, the tricarboxylic acid cycle and energy-related pathways, and ion transmembrane transport and cellular water homeostasis, with the aquaporin family showing the highest differential levels of persulfidation. We revealed that water transport activity is regulated by sulfide which correlates with an increasing level of persulfidation of aquaporins. Our findings emphasize the impact of persulfidation on total ATP levels, fatty acid composition, levels of reactive oxygen species, antioxidant enzymatic activities, and relative water content. Interestingly, the role of persulfidation in aquaporin transport activity as an adaptation response in rice differs from current knowledge of Arabidopsis, which highlights the distinct role of sulfide in improving rice tolerance to drought.

The authors thank Dr Concha Domingo for kindly providing rice seeds. The authors acknowledge the technical assistance of Carlos Parejo at the Chromatography facility of the Instituto de Bioquímica Vegetal y Fotosíntesis. This work was supported by ERDF A way of making Europe and MCIN/AEI/10.13039/501100011033 and NextGenerationEU/PRTR (grant nos PID2019-109785GB-I00, PID2020-112645GB-I00, TED2021-131443B-I00, and PID2022-141885NB-I00); CSIC (grant no. 2023AEP077); Junta de Andalucía (grant nos P18-RT-3154 and PROYEXCEL_00177); and Jiangsu Natural Science Foundation for Distinguished Young Scholars (BK20220084 to YX). JZ was supported by a scholarship under the State Scholarship Fund of the China Scholarship Council.

Peer reviewed