Division of Life Sciences and Medicine, Division of Molecular & Cell Biophysics, Hefei National Science Center for Physical Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, University of Science and Technology of China, The Innovation Academy of Seed Design, Chinese Academy of Sciences, Hefei, Anhui Province 230027, China.
Division of Life Sciences and Medicine, Division of Molecular & Cell Biophysics, Hefei National Science Center for Physical Sciences at the Microscale, MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, University of Science and Technology of China, The Innovation Academy of Seed Design, Chinese Academy of Sciences, Hefei, Anhui Province 230027, China.
Plant Commun. 2023 Mar 13;4(2):100458. doi: 10.1016/j.xplc.2022.100458. Epub 2022 Oct 4.
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. OsMADS27 knockout mutants are more sensitive to salt stress than the wild type, whereas 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 demonstrate 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 the enhancement of salt tolerance by nitrogen fertilizers in rice. 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.
盐胁迫是植物生长和产量的主要限制因素。已知氮肥可缓解盐胁迫。然而，其潜在的分子机制仍不清楚。在这里，我们表明硝酸盐依赖的耐盐性是由水稻中的 OsMADS27 介导的。OsMADS27 的表达特异性地被硝酸盐诱导。OsMADS27 的盐诱导表达也依赖于硝酸盐。与野生型相比，OsMADS27 敲除突变体对盐胁迫更敏感，而 OsMADS27 过表达系更耐受。转录组分析表明，OsMADS27 上调了许多已知的应激响应基因以及参与离子稳态和抗氧化的基因的表达。我们证明 OsMADS27 直接与 OsHKT1.1 和 OsSPL7 的启动子结合，以调节它们的表达。值得注意的是，OsMADS27 介导的耐盐性依赖于硝酸盐，并且与硝酸盐浓度呈正相关。我们的研究结果揭示了硝酸盐响应的 OsMADS27 及其下游靶基因在耐盐性中的作用，为氮肥在水稻中增强耐盐性提供了分子机制。在有足够硝酸盐的情况下，OsMADS27 过表达增加了盐胁迫下的籽粒产量，这表明 OsMADS27 是提高水稻耐盐性的有希望的候选基因。
