Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China; Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing, China.
Key Laboratory of Crop Physiology Ecology and Production Management, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China; Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing, China; National Engineering and Technology Center for Information Agriculture, Nanjing, China.
Ecotoxicol Environ Saf. 2020 Dec 15;206:111358. doi: 10.1016/j.ecoenv.2020.111358. Epub 2020 Sep 30.
Rice (Oryza sativa L.) productivity is greatly affected by soil salinity and melatonin (MLT) has long been recognized as a positive molecule that can alleviate the damage caused by salt. Here, the role of nitric oxide (NO) in the regulation of salt tolerance by MLT was investigated in rice. MLT pretreatment increased the fresh and dry weight of rice seedlings under salt stress. Its beneficial effects include less relative electrolyte leakage (REL) and better K/Na homeostasis. MLT increased the activity of nitric oxide synthase (NOS). The polyamines (PAs) content and the utilization of arginine were also increased, thereby increasing NO content in salt-stressed rice seedlings. Pharmacological approach showed that NO, as a necessary downstream signaling molecule, was involved in the regulation of MLT on the K/Na homeostasis of rice. Under salt stress, MLT improved the H-pumps activities in plasma membrane (PM) and vacuole membrane (VM) in roots, MLT also increased the ATP content of rice roots by increasing the NO content of rice. Thus, the efflux of Na and the influx of K were promoted. When endogenous NO was scavenged, the regulation of K/Na homeostasis by MLT was blocked. Therefore, MLT mediated K/Na homeostasis of rice under salt stress by mediating NO.
水稻（Oryza sativa L.）的生产力受土壤盐度的影响很大，而褪黑素（MLT）长期以来一直被认为是一种积极的分子，可以减轻盐造成的损害。在这里，研究了一氧化氮（NO）在 MLT 调节水稻耐盐性中的作用。MLT 预处理可增加盐胁迫下水稻幼苗的鲜重和干重。其有益作用包括相对电解质渗漏（REL）减少和更好的 K/Na 稳态。MLT 增加了一氧化氮合酶（NOS）的活性。多胺（PAs）含量和精氨酸的利用也增加，从而增加了盐胁迫下水稻幼苗中的 NO 含量。药理方法表明，NO 作为一种必需的下游信号分子，参与了 MLT 对水稻 K/Na 稳态的调节。在盐胁迫下，MLT 改善了根中质膜（PM）和液泡膜（VM）的 H-泵活性，MLT 还通过增加水稻根中的 NO 含量来增加水稻根中的 ATP 含量。因此，促进了 Na 的外排和 K 的内流。当内源性 NO 被清除时，MLT 对 K/Na 稳态的调节被阻断。因此，MLT 通过介导 NO 来介导盐胁迫下水稻的 K/Na 稳态。
