College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, China.
Center of Hydrogen Science, Shanghai Jiao Tong University, Shanghai, China.
Plant Cell Environ. 2021 Feb;44(2):476-490. doi: 10.1111/pce.13926. Epub 2020 Nov 5.
Melatonin (MT) plays positive roles in salinity stress tolerance. However, the upstream signalling components that regulate MT are poorly understood. Here, we report that endogenous MT acts downstream of molecular hydrogen (H ) in the salinity response in Arabidopsis. The addition of hydrogen-rich water and expression of the hydrogenase1 gene (CrHYD1) from Chlamydomonas reinhardtii increased endogenous H and MT levels and enhanced salinity tolerance. These results were not observed in the absence of serotonin N-acetyltransferase gene (SNAT). H increased the levels of SNAT transcripts in the wild-type and CrHYD1 lines, which had lower Na /K ratios and higher levels of ion transport-related gene transcripts. These changes were not observed in atsnat/CrHYD1-4 hybrids. The increased MT-dependent Na extrusion observed in the CrHYD1 plants resulted, at least in part, from enhanced Na /H antiport across the plasma membrane. The endogenous H -induced MT-dependent regulation of ion and redox homeostasis was impaired in the atsnat/CrHYD1-4 hybrids. Taken together, these results demonstrate that MT-induced salinity tolerance is induced by a H signalling cascade that regulates ion and redox homeostasis in response to salinity.
褪黑素 (MT) 在耐盐性方面发挥积极作用。然而，调节 MT 的上游信号成分知之甚少。在这里，我们报告说内源性 MT 在拟南芥的盐度响应中位于分子氢 (H ) 的下游。添加富含氢气的水和小球藻 (Chlamydomonas reinhardtii) 的氢化酶 1 基因 (CrHYD1) 的表达增加了内源性 H 和 MT 水平并增强了耐盐性。在没有血清素 N-乙酰转移酶基因 (SNAT) 的情况下，没有观察到这些结果。H 在野生型和 CrHYD1 系中增加了 SNAT 转录本的水平，这导致 Na /K 比值降低，离子转运相关基因转录本水平升高。在 atsnat/CrHYD1-4 杂种中未观察到这些变化。在 CrHYD1 植物中观察到的依赖 MT 的 Na 外排增加至少部分归因于质膜中 Na /H 反向转运的增强。atsnat/CrHYD1-4 杂种中内源性 H 诱导的 MT 依赖性离子和氧化还原稳态调节受损。总之，这些结果表明，MT 诱导的耐盐性是由调节离子和氧化还原稳态以响应盐度的 H 信号级联诱导的。
