PDF(Pubmed)
Abstract：
Brassinosteroids (BRs), the sixth major phytohormone, can regulate plant salt tolerance. Many studies have been conducted to investigate the effects of BRs on plant salt tolerance, generating a large amount of research data. However, a meta-analysis on regulating plant salt tolerance by BRs has not been reported. Therefore, this study conducted a meta-analysis of 132 studies to elucidate the most critical physiological mechanisms by which BRs regulate salt tolerance in plants from a higher dimension and analyze the best ways to apply BRs. The results showed that exogenous BRs significantly increased germination, plant height, root length, and biomass (total dry weight was the largest) of plants under salt stress. There was no significant difference between seed soaking and foliar spraying. However, the medium method (germination stage) and stem application (seedling stage) may be more effective in improving plant salt tolerance. BRs only inhibit germination in Solanaceae. BRs (2 μM), seed soaking for 12 h, and simultaneous treatment with salt stress had the highest germination rate. At the seedling stage, the activity of Brassinolide (C28H48O6) was higher than that of Homobrassinolide (C29H50O6), and post-treatment, BRs (0.02 μM) was the best solution. BRs are unsuitable for use in the germination stage when Sodium chloride is below 100 mM, and the effect is also weakest in the seedling stage. Exogenous BRs promoted photosynthesis, and antioxidant enzyme activity increased the accumulation of osmoregulatory and antioxidant substances and reduced the content of harmful substances and Na+, thus reducing cell damage and improving plant salt tolerance. BRs induced the most soluble protein, chlorophyll a, stomatal conductance, net photosynthetic rate, Glutathione peroxidase, and root-Ca2+, with BRs causing Ca2+ signals in roots probably constituting the most important reason for improving salt tolerance. BRs first promoted the accumulation of Ca2+ in roots, which increased the content of the above vital substances and enzyme activities through the Ca2+ signaling pathway, improving plant salt tolerance.
摘要：
油菜素类固醇(BRs),第六大植物激素，可以调节植物的耐盐性。已经进行了许多研究来研究BRs对植物耐盐性的影响，产生了大量的研究数据。然而,关于BRs调节植物耐盐性的荟萃分析尚未报道。因此,这项研究对132项研究进行了荟萃分析,以阐明BRs从更高维度调节植物耐盐性的最关键生理机制,并分析应用BRs的最佳方法.结果表明，外源BRs显著提高了发芽率，植物高度,根长,和植物在盐胁迫下的生物量（总干重最大）。种子浸泡和叶面喷施之间没有显着差异。然而,培养基法(萌发期)和茎施用法(幼苗期)可能更有效地提高植物耐盐性。BRs仅抑制茄科的萌发。BRs(2μM),种子浸泡12小时，与盐胁迫同时处理的发芽率最高。在幼苗阶段，油菜素内酯(C28H48O6)的活性高于同油菜素内酯(C29H50O6),和后处理，BRs(0.02μM)是最好的溶液。当氯化钠低于100mM时，BRs不适合用于发芽阶段，在苗期效果也最弱。外源BRs促进光合作用，抗氧化酶活性增加了渗透调节和抗氧化物质的积累，降低了有害物质和Na+的含量，从而减少细胞损伤，提高植物耐盐性。BRs诱导的最可溶性蛋白，叶绿素a,气孔导度,净光合速率，谷胱甘肽过氧化物酶,和根-Ca2+，BRs在根中引起Ca2信号可能是提高耐盐性的最重要原因。BRs首先促进了根中Ca2+的积累，通过Ca2+信号通路增加上述重要物质的含量和酶活性,提高植物耐盐性。
