College of Life Science, Shandong Normal University , Jinan , P.R. China.
Plant Signal Behav. 2019;14(10):e1644595. doi: 10.1080/15592324.2019.1644595. Epub 2019 Jul 22.
Salicylic acid (SA) may improve plant tolerance to abiotic stresses; however, little is known about the underlying mechanisms by which this is achieved. Here, we investigated the effects of exogenous SA application on seed germination in the halophyte (Kuntze) under salt stress. Specifically, we examined the effect of salt stress on seed germination, sugar and protein contents, amylase activity, and the contents of various hormones, both in the presence and absence of exogenous SA treatments. Germination was significantly suppressed by a 200 mM NaCl treatment but was significantly improved when 0.08 mM SA was concurrently applied. During germination, the seeds treated with SA had high levels of gibberellic acid (GA) and high levels of amylase and α-amylase activity, but low abscisic acid (ABA) contents. The SA treatment upregulated the expression of key genes involved in GA biosynthesis while downregulating those involved in ABA biosynthesis, thereby triggering a favorable hormonal balance between GA and ABA that enhanced seed germination under salt stress.
水杨酸（SA）可以提高植物对非生物胁迫的耐受性；然而，其作用机制知之甚少。在这里，我们研究了外源 SA 处理对盐胁迫下盐生植物（Kuntze）种子萌发的影响。具体来说，我们研究了盐胁迫对种子萌发、糖和蛋白质含量、淀粉酶活性以及各种激素含量的影响，同时考察了外源 SA 处理的存在与否的影响。200mM NaCl 处理显著抑制萌发，但同时添加 0.08mM SA 时显著提高。在萌发过程中，用 SA 处理的种子中赤霉素（GA）含量高，淀粉酶和α-淀粉酶活性高，但脱落酸（ABA）含量低。SA 处理上调了参与 GA 生物合成的关键基因的表达，同时下调了参与 ABA 生物合成的关键基因的表达，从而在盐胁迫下触发了 GA 和 ABA 之间有利的激素平衡，从而促进了种子萌发。
