Basic Medical College, Shaoyang University, Shaoyang, 422000, China.
State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
J Plant Physiol. 2023 Aug;287:154048. doi: 10.1016/j.jplph.2023.154048. Epub 2023 Jun 29.
Drought and salt are major abiotic stresses that severely restricts plant growth and development, leading to serious losses in agricultural production. Therefore, improving crop tolerance to drought and salt stresses is an urgent issue. A previous study showed that overexpression of Arabidopsis NLR gene AtRPS2 conferred broad-spectrum disease resistance in rice. In this study, we demonstrated that constitutive expression of AtRPS2 increased abscisic acid (ABA) sensitivity during seedling stage, the shoot length of transgenic plants were shorter than wild type plants. Exogenous application of ABA markedly induced the expression of stress-related genes and promoted stomatal close in transgenic plants. Overexpression of AtRPS2 also enhanced drought and salt tolerance in rice, transgenic plants exhibited higher survival rates under drought and salt conditions than wild type plants. The activities of catalase (CAT) and superoxide dismutase (SOD) were higher in AtRPS2 transgenic rice than wild type plants. In addition, the expression of stress-related genes and ABA-responsive genes were significantly upregulated in AtRPS2 transgenic plants than wild type plants under drought and salt treatments. Besides, exogenous application of ABA could facilitate drought and salt tolerance in AtRPS2 transgenic plants. Taken together, this study indicated that AtRPS2 could improve drought and salt tolerance in rice, and this phenomenon is likely to be regulated through ABA signaling pathways.
干旱和盐胁迫是严重限制植物生长和发育的主要非生物胁迫因素，导致农业生产严重损失。因此，提高作物对干旱和盐胁迫的耐受性是一个紧迫的问题。先前的研究表明，拟南芥 NLR 基因 AtRPS2 的过表达赋予了水稻广谱的抗病性。在本研究中，我们证明了 AtRPS2 的组成型表达在幼苗期增加了脱落酸（ABA）的敏感性，转基因植株的茎长比野生型植株短。外源 ABA 的应用显著诱导了与胁迫相关基因的表达，并促进了转基因植株中气孔的关闭。AtRPS2 的过表达也增强了水稻的耐旱性和耐盐性，转基因植株在干旱和盐胁迫条件下的存活率高于野生型植株。与野生型植株相比，AtRPS2 转基因水稻中的过氧化氢酶（CAT）和超氧化物歧化酶（SOD）活性更高。此外，在干旱和盐处理下，AtRPS2 转基因植株中与胁迫相关基因和 ABA 响应基因的表达明显上调。此外，外源 ABA 的应用可以促进 AtRPS2 转基因植株的耐旱性和耐盐性。综上所述，本研究表明 AtRPS2 可以提高水稻的耐旱性和耐盐性，这种现象可能是通过 ABA 信号通路来调节的。
