Chloroplast sunscreening by protein condensates confers high-light tolerance

Cell, 17 June, 2026, DOI：https://doi.org/10.1016/j.cell.2026.05.042

Chloroplast sunscreening by protein condensates confers high-light tolerance

Ning Shao, Mingjiang Chen, Ning Xu, Yaqiang Qin, Qian Zhao, Ralph Bock, Min Zhou, Guangyou Duan, Jing Yang, Daili Ji, Dongshan Wu, Yu Wang, Yinghong Lu, Xiaoguang Lei, Kai Sun, Keke Liu, Guifu Liu, Xiangbing Meng, Yanhui Jing, Xiuli Fan, Yannan Zhao, Bing Wang, Hong Yu, Cuimin Liu, Yuqiang Jiang, Zheng Zhou, Jiayang Li

Abstract

Sunlight fuels life but generates singlet oxygen (¹O₂), which causes photodamage and triggers signaling and antioxidative defense pathways in chloroplasts where photosynthesis takes place. How cells sense ¹O₂ and instantaneously mount photoprotection remains elusive. Here, we show that a key mediator of ¹O₂ responses, METHYLENE BLUE SENSITIVITY1 (MBS1), is conserved from plants to animals and comprises a zinc-finger (ZnF) domain flanked by intrinsically disordered regions. MBS1 plays a critical role in ¹O₂ sensing through ZnF conformational change and phase transition from liquid-like droplets to lower-dynamic condensates. These chloroplast-associated condensates under high light attenuate light penetration to shield chloroplasts from photodamage. In rice, MBS1-overexpressing lines exhibit enhanced high-light tolerance and yield in 4-year field trials. Our findings uncover a “sunscreening” mechanism via MBS1 condensates that confer chloroplast photoprotection, highlighting its value for improving rice yields in the field under high-light stress exacerbated by climate change.

文章链接：https://www.sciencedirect.com/science/article/pii/S0092867426006422?via%3Dihub