Liu Shuang, Wang Shoumin, Zheng Yuying, Zhao Panpan, Jin Hongpei, Xie Guosheng
MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
Guangxi Salt-Alkali Tolerant Food Crop Seed Engineering Research Center, College of Agricultural Engineering, Guangxi Vocational University of Agriculture, Nanning, 530007, China.
Plant J. 2025 Aug;123(3):e70420. doi: 10.1111/tpj.70420.
Salt stress induces cytoplasmic calcium (Ca) ion spikes and activates Ca/ calmodulin (CaM) signaling in plant cells. Calmodulin-binding transcription activators (CAMTAs) are pivotal components of Ca/CaM-mediated abiotic stress responses. Nevertheless, how Ca/CaM specifically interacts with the OsCAMTAs family members to modulate salinity tolerance is largely undetermined in rice. Through integrated molecular genetics, biochemical, and physiological analyses, we demonstrated that OsCaM1/2/3 interacted specifically with OsCAMTA1/2/4/6 in a Ca-dependent manner. Transgenics showed OsCaM1-1 and OsCAMTA1 enhanced salinity tolerance in rice. RNA-sequence (RNA-seq) profiling of oscamta1 lines suggested that OsCAMTA1 positively regulates salinity tolerance by orchestrating downstream targets involved in Ca binding, hormonal responses, transcriptional regulation, and salt stress pathways. The dual-luciferase (LUC) assays identified that OsCaM1 activates the transcriptional activity of OsCAMTA1 to the targets OsDREB1B and OsCML16, respectively, both of which positively regulate the salinity tolerance in rice seedlings. Transcriptomic screening revealed that OsCAMTA1 and OsDREB1B co-regulated the genes OsZFP179, OsMST4, and Oshox22, while OsCAMTA1 and OsCML16 co-regulated the genes OsP5CS, OsABI5-1, and OsHAK24 under salt stress. Our study reveals a novel OsCaM1-OsCAMTA1 module to regulate the OsDREB1B/OsCML16 transcriptional cascade under salt stress, providing candidate genes for breeding salt-adapted rice varieties in the future.
盐胁迫诱导植物细胞质中钙离子（Ca）产生尖峰，并激活植物细胞中的Ca/钙调蛋白（CaM）信号传导。钙调蛋白结合转录激活因子（CAMTAs）是Ca/CaM介导的非生物胁迫反应的关键组成部分。然而，在水稻中，Ca/CaM如何与OsCAMTAs家族成员特异性相互作用以调节耐盐性在很大程度上仍未确定。通过整合分子遗传学、生化和生理分析，我们证明了OsCaM1/2/3以Ca依赖的方式与OsCAMTA1/2/4/6特异性相互作用。转基因研究表明，OsCaM1-1和OsCAMTA1增强了水稻的耐盐性。oscamta1株系的RNA测序（RNA-seq）分析表明，OsCAMTA1通过协调参与Ca结合、激素反应、转录调控和盐胁迫途径的下游靶点来正向调节耐盐性。双荧光素酶（LUC）分析确定，OsCaM1分别激活OsCAMTA1对靶点OsDREB1B和OsCML16的转录活性，这两个靶点均正向调节水稻幼苗的耐盐性。转录组筛选显示，在盐胁迫下，OsCAMTA1和OsDREB1B共同调节基因OsZFP179、OsMST4和Oshox22，而OsCAMTA1和OsCML16共同调节基因OsP5CS、OsABI5-1和OsHAK24。我们的研究揭示了一个新的OsCaM1-OsCAMTA1模块，在盐胁迫下调节OsDREB1B/OsCML16转录级联反应，为未来培育耐盐水稻品种提供了候选基因。
