Chen Qi, Xu Kai, Xu Yan, Ji Dehua, Chen Changsheng, Xie Chaotian, Wang Wenlei
Fisheries College, Jimei University, Xiamen, China.
Fujian Engineering Research Center of Aquatic Breeding and Healthy Aquaculture, Fujian Development and Reform Commission, Xiamen, China.
Front Plant Sci. 2023 Jan 4;13:1040142. doi: 10.3389/fpls.2022.1040142. eCollection 2022.
In plants under hypersaline stress, the main transporter that extrudes sodium ions (Na ) is the Na /H antiporter SOS1. Different from land plants, the intertidal macroalgae, contains an animal-type Na /K -ATPase as well as the SOS1 system. However, the contribution of Na /K -ATPase to the K /Na homeostasis of intertidal macroalgae remains unclear. In this study, we analyzed the function of Na /K -ATPase in the response of to salt stress from the perspective of ion transport dynamics. Both the transcript level of and enzyme activity of Na /K -ATPase increased in the early response of thalli to hypersaline stress. Addition of ouabain, an inhibitor of Na /K -ATPase, resulted in Na accumulation in the cells, severe K leakage from the thalli, and then remarkably disturbed the K /Na homeostasis in thalli. This disruption might induce a significant decrease in photosynthesis and a severe oxidative damage in thalli. Accordingly, these results suggested that the important role of Na /K -ATPase in the resistance of intertidal macroalgae to hypersaline stress, and shed light on the diversity of K /Na homeostasis maintenance mechanisms in plants.
在遭受高盐胁迫的植物中，排出钠离子（Na⁺）的主要转运蛋白是Na⁺/H⁺逆向转运蛋白SOS1。与陆地植物不同，潮间带大型海藻除了含有SOS1系统外，还含有一种动物型Na⁺/K⁺-ATP酶。然而，Na⁺/K⁺-ATP酶对潮间带大型海藻K⁺/Na⁺稳态的贡献仍不清楚。在本研究中，我们从离子转移动力学的角度分析了Na⁺/K⁺-ATP酶在大型海藻对盐胁迫响应中的功能。大型海藻叶状体对高盐胁迫的早期响应中，Na⁺/K⁺-ATP酶的转录水平和酶活性均升高。添加Na⁺/K⁺-ATP酶抑制剂哇巴因会导致细胞内Na⁺积累，叶状体中K⁺严重泄漏，进而显著扰乱大型海藻叶状体中的K⁺/Na⁺稳态。这种破坏可能导致光合作用显著下降和叶状体严重氧化损伤。因此，这些结果表明Na⁺/K⁺-ATP酶在潮间带大型海藻对高盐胁迫的抗性中起重要作用，并揭示了植物中K⁺/Na⁺稳态维持机制的多样性。
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