Wang Jun, Cai Chenxu, Geng Puze, Tan Feng, Yang Qing, Wang Ren, Shen Wenbiao
College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China.
Antioxidants (Basel). 2022 Jun 14;11(6):1168. doi: 10.3390/antiox11061168.
Argon, a non-polar molecule, easily diffuses into deeper tissue and interacts with larger proteins, protein cavities, or even receptors. Some of the biological effects of argon, notably its activity as an antioxidant, have been revealed in animals. However, whether and how argon influences plant physiology remains elusive. Here, we provide the first report that argon can enable plants to cope with salinity toxicity. Considering the convenience of the application, argon gas was dissolved into water (argon-rich water (ARW)) to investigate the argon's functioning in phenotypes of alfalfa seed germination and seedling growth upon salinity stress. The biochemical evidence showed that NaCl-decreased /-amylase activities were abolished by the application of ARW. The qPCR experiments confirmed that ARW increased (Na/H antiporter) transcript and decreased (responsible for root-to-shoot translocation of K) mRNA abundance, the latter of which could be used to explain the lower net K efflux and higher K accumulation. Subsequent results using non-invasive micro-test technology showed that the argon-intensified net Na efflux and its reduced Na accumulation resulted in a lower Na/K ratio. NaCl-triggered redox imbalance and oxidative stress were impaired by ARW, as confirmed by histochemical and confocal analyses, and increased antioxidant defense was also detected. Combined with the pot experiments in a greenhouse, the above results clearly demonstrated that argon can enable plants to cope with salinity toxicity via reestablishing ion and redox homeostasis. To our knowledge, this is the first report to address the function of argon in plant physiology, and together these findings might open a new window for the study of argon biology in plant kingdoms.
氩气是一种非极性分子，它很容易扩散到更深层的组织中，并与较大的蛋白质、蛋白质腔甚至受体相互作用。氩气的一些生物学效应，尤其是其作为抗氧化剂的活性，已在动物实验中得到揭示。然而，氩气是否以及如何影响植物生理过程仍然不清楚。在此，我们首次报道氩气能够使植物应对盐胁迫毒性。考虑到应用的便利性，将氩气溶解于水中（富氩水，ARW），以研究氩气在盐胁迫下对苜蓿种子萌发和幼苗生长表型的作用。生化证据表明，施用ARW消除了NaCl降低的淀粉酶活性。定量PCR实验证实，ARW增加了（Na/H逆向转运蛋白）转录本，并降低了（负责钾从根部向地上部转运）mRNA丰度，后者可用于解释较低的净钾外流和较高的钾积累。随后使用非损伤微测技术的结果表明，氩气增强了净钠外流并减少了钠积累，从而导致较低的钠/钾比。组织化学和共聚焦分析证实，ARW减轻了NaCl引发的氧化还原失衡和氧化应激，并且还检测到抗氧化防御增强。结合温室盆栽实验，上述结果清楚地表明，氩气能够通过重新建立离子和氧化还原稳态使植物应对盐胁迫毒性。据我们所知，这是第一份关于氩气在植物生理学中功能的报告，这些发现共同可能为植物界氩气生物学的研究打开一扇新窗口。
