Stress response membrane protein OsSMP2 negatively regulates rice tolerance to drought

Wei Wang, Yaqi Li, Songjin Yang, Jiacheng Wu, Chuan Ma, Yulin Chen, Xingzhuo Sun, Lingli Wu, Xin Liang, Qiuping Fu, Zhengjun Xu, Lihua Li, Zhengjian Huang, Jianqing Zhu, Xiaomei Jia, Xiaoying Ye, Rongjun Chen

Journal of Experimental Botany, Volume 75, Issue 11, 7 June 2024（IF=6.9）

https://doi.org/10.1093/jxb/erae097

Abstract

In a gene chip analysis, rice (Oryza sativa) OsSMP2 gene expression was induced under various abiotic stresses, prompting an investigation into its role in drought resistance and abscisic acid signaling. Subsequent experiments, including qRT–PCR and β-glucuronidase activity detection, affirmed the OsSMP2 gene’s predominant induction by drought stress. Subcellular localization experiments indicated the OsSMP2 protein primarily localizes to the cell membrane system. Overexpressing OsSMP2 increased sensitivity to exogenous abscisic acid, reducing drought resistance and leading to reactive oxygen species accumulation under drought stress. Conversely, in simulated drought experiments, OsSMP2-silenced transgenic plants showed significantly longer roots compared with the wild-type Nipponbare. These results suggest that OsSMP2 overexpression negatively affects rice drought resistance, offering valuable insights into molecular mechanisms, and highlight OsSMP2 as a potential target for enhancing crop resilience to drought stress.

Keyword: Abscisic acid, drought, gene, reactive oxygen species, rice, roots