Alamin Alfatih, Jing Zhang, Ying Song, Sami Ullah Jan, Zi-Sheng Zhang, Jing-Qiu Xia, Zheng-Yi Zhang, Tahmina Nazish, Jie Wu, Ping-Xia Zhao, Cheng-Bin Xiang

Plant Commun; 2022 Oct 4; 100458.  doi: 10.1016/j.xplc.2022.100458. Online ahead of print.

Abstract

Salt stress is a major constraint on plant growth and yield. Nitrogen (N) fertilizers are known to alleviate salt stress. However, the underlying molecular mechanisms remain unclear. Here, we show that nitrate-dependent salt tolerance is mediated by OsMADS27 in rice. The expression of OsMADS27 is specifically induced by nitrate. The salt-inducible expression of OsMADS27 is also nitrate-dependent. The OsMADS27 knockout mutants are more sensitive to salt stress than the wild type, whereas the OsMADS27 overexpression lines are more tolerant. Transcriptomic analyses revealed that OsMADS27 upregulates the expression of a number of known stress-responsive genes as well as those involved in ion homeostasis and antioxidation. We demonstrated that OsMADS27 directly binds to the promoters of OsHKT1.1 and OsSPL7 to regulate their expression. Notably, OsMADS27-mediated salt tolerance is nitrate-dependent and positively correlated with nitrate concentration. Our results reveal the role of nitrate-responsive OsMADS27 and its downstream target genes in salt tolerance, providing a molecular mechanism for nitrogen fertilizers-enhanced salt tolerance in rice. Moreover, OsMADS27 overexpression increased grain yield under salt stress in the presence of sufficient nitrate, suggesting that OsMADS27 is a promising candidate for the improvement of salt tolerance in rice.

See https://pubmed.ncbi.nlm.nih.gov/36199247/

Figure 1. OsMADS27 is specifically responsive to nitrate.806