Ethylene improves Arabidopsis salt tolerance mainly via retaining K+ in shoots and roots rather than decreasing tissue Na+ content
Ethylene improves Arabidopsis salt tolerance mainly via retaining K+ in shoots and roots rather than decreasing tissue Na+ content
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DOI：
10.1016/j.envexpbot.2010.08.006
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发表时间：
2013-02
影响因子：
5.7
通讯作者：
Lei Yang;Y. Zu;Zhonghua Tang
中科院分区：
文献类型：
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作者：
Lei Yang;Y. Zu;Zhonghua Tang
据报道，乙烯在拟南芥对盐度和K+缺乏的反应中起着重要作用。植物体内钾离子的维持和钠离子的减少是植物耐盐性的关键。目前还不清楚乙烯是如何调节植物离子稳态在盐水场合。我们采用拟南芥野生型（Col-0），乙烯不敏感突变体（ein 2 -5和ein 3 -1）和组成型三重响应突变体（ctr 1 -1）植物，比较其表型和生理反应的盐度。乙烯利能迅速转化为乙烯，本文以Col-0幼苗为试材，验证乙烯在盐胁迫下的作用。我们发现，乙烯不敏感ein 2 -5或ein 3 -1植物增加拟南芥盐敏感性比Col-0。然而，与Col-0相比，ctr 1 -1的叶绿素a/B、光系统II功能（Fv/Fm）和氧化还原态在重度盐胁迫下得到了明显的改善。ctr 1 -1植株的可溶性糖和抗氧化系统也被上调，以提高ST。乙烯利明显缓解了盐胁迫对根长的限制。随后对Na+和K+动态平衡的分析发现，乙烯可以帮助植物在短期或长期盐胁迫下保持较高的地上部或根部K+营养。然而，乙烯并没有显着改变盐胁迫植物的钠积累和水分关系。我们的观察证实了乙烯在改善植物ST中的关键作用，并强调了乙烯在芽和根中保留K+而不是减少Na+以改善拟南芥ST的能力。
Ethylene has been reported to play an essential role in the response of Arabidopsis to salinity and K+deficiency. It was proposed that plant's ability to maintain potassium (K+) and minimize sodium (Na+) in tissues of salinity plants is critical for salt tolerance (ST). It is still unclear how ethylene modulates plant ion homeostasis under saline occasions. We employed Arabidopsis wild type (Col-0), ethylene insensitive mutants (ein2-5 and ein3-1) and constitutive triple response mutant (ctr1-1) plants to compare their phenotypic and physiological responses to salinity. Ethephon applied to plants could convert quickly to ethylene and here was applied exogenously to Col-0 seedlings to validate ethylene role in salt response. We showed that ethylene insensitivity in ein2-5 or ein3-1 plants increased Arabidopsis salt sensitivity than in Col-0. However, the salinity-induced adverse effects on Chlorophyll a/b, photosystem II function (Fv/Fm) and redox state were largely amended in the ctr1-1 than in Col-0 plants with the severe salinity. The compatible solute sucrose and antioxidant system were also up-regulated to improve ST in ctr1-1 plants. The ethephon obviously alleviated the salinity-induced restriction in root length. The subsequent analysis on the Na+and K+homeostasis found that ethylene could help plant retain higher shoot or root K+nutrition in the short- or long-term salt-stressed plants. However, the ethylene did not significantly alter sodium buildup and water relation in the salt-stressed plants. Our observations confirmed the key role of ethylene in improved plant ST and highlighted the ethylene ability to retain K+, rather than decreasing Na+, in shoots and roots to improve Arabidopsis ST.