Wang Zhidan, Wang Mugui, Yang Changhong, Zhao Lun, Qin Guochen, Peng Li, Zheng Qijie, Nie Wenfeng, Song Chun-Peng, Shi Huazhong, Zhu Jian-Kang, Zhao Chunzhao
Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Stress Biol. 2021 Sep 29;1(1):9. doi: 10.1007/s44154-021-00010-5.
Maintenance of cell wall integrity is of great importance not only for plant growth and development, but also for the adaptation of plants to adverse environments. However, how the cell wall integrity is modulated under salt stress is still poorly understood. Here, we report that a nuclear-localized Agenet domain-containing protein SWO1 (SWOLLEN 1) is required for the maintenance of cell wall integrity in Arabidopsis under salt stress. Mutation in SWO1 gene results in swollen root tips, disordered root cell morphology, and root elongation inhibition under salt stress. The swo1 mutant accumulates less cellulose and pectin but more lignin under high salinity. RNA-seq and ChIP-seq assays reveal that SWO1 binds to the promoter of several cell wall-related genes and regulates their expression under saline conditions. Further study indicates that SWO1 interacts with importin ɑ IMPA1 and IMPA2, which are required for the import of nuclear-localized proteins. The impa1 impa2 double mutant also exhibits root growth inhibition under salt stress and mutations of these two genes aggravate the salt-hypersensitive phenotype of the swo1 mutant. Taken together, our data suggest that SWO1 functions together with importin ɑ to regulate the expression of cell wall-related genes, which enables plants to maintain cell wall integrity under high salinity.
维持细胞壁完整性不仅对植物的生长发育至关重要，而且对于植物适应逆境环境也非常重要。然而，盐胁迫下细胞壁完整性是如何被调控的仍知之甚少。在此，我们报道了一种定位于细胞核的含Agenet结构域的蛋白SWO1（肿胀1）在盐胁迫下对拟南芥细胞壁完整性的维持是必需的。SWO1基因突变导致盐胁迫下根尖肿胀、根细胞形态紊乱以及根伸长受到抑制。在高盐度条件下，swo1突变体积累的纤维素和果胶较少，但木质素较多。RNA测序和染色质免疫沉淀测序分析表明，SWO1在盐胁迫条件下与几个细胞壁相关基因的启动子结合并调节它们的表达。进一步研究表明，SWO1与核定位蛋白导入所需的输入蛋白α IMPA1和IMPA2相互作用。impa1 impa2双突变体在盐胁迫下也表现出根生长抑制，并且这两个基因的突变加剧了swo1突变体的盐超敏表型。综上所述，我们的数据表明，SWO1与输入蛋白α共同作用来调节细胞壁相关基因的表达，从而使植物在高盐度下能够维持细胞壁的完整性。
