College of Horticulture, Northwest A&F University, Yangling 712100, China.
State Key Laboratory of Crop Stress Biology in Arid Regions, Northwest A&F University, Yangling 712100, China.
Molecules. 2019 Feb 3;24(3):556. doi: 10.3390/molecules24030556.
Mitogen-activated protein kinases (MAPKs) activation is a common defense response of plants to a range of abiotic stressors. , a serine-threonine protein kinase, has been reported as an important member of protein kinase cascade that also functions on plant stress tolerance. In this study, we cloned from tomato and studied its role in cadmium (Cd) and drought tolerance. The results showed that transcripts of differentially accumulated in various plant tissues and were remarkably induced by different abiotic stressors and exogenous hormone treatments. Overexpression of increased tolerance to Cd and drought as reflected by an increased germination rate and improved seedling growth. Furthermore, transgenic plants overexpressing showed an increased leaf chlorophyll content, root biomass accumulation and root activity under Cd stress. Chlorophyll fluorescence analysis revealed that transgenic plants demonstrated an increased photosynthetic activity as well as contents of chlorophyll, proline, and sugar under drought stress. Notably, cadmium- and drought-induced oxidative stress was substantially attenuated in overexpressing plants as evidenced by lower malondialdehyde and hydrogen peroxide accumulation, and increased activity and transcript abundance of enzymatic antioxidants under stress conditions compared to that of wild-type. Our findings provide solid evidence that overexpression of gene in tomato positively regulates tolerance to Cd and drought stress, which may have strengthen the molecular understanding of gene to improve abiotic stress tolerance.
丝裂原活化蛋白激酶（MAPKs）的激活是植物对多种非生物胁迫的常见防御反应。作为蛋白激酶级联反应的重要成员，已被报道在植物应激耐受中发挥作用。在这项研究中，我们从番茄中克隆了，并研究了其在镉（Cd）和干旱耐受性中的作用。结果表明，在不同的植物组织中转录物差异积累，并被不同的非生物胁迫和外源激素处理显著诱导。过表达增加了对 Cd 和干旱的耐受性，表现在发芽率提高和幼苗生长改善。此外，过表达的转基因植物在 Cd 胁迫下表现出增加的叶片叶绿素含量、根生物量积累和根活力。叶绿素荧光分析表明，转基因植物在干旱胁迫下表现出更高的光合作用活性以及叶绿素、脯氨酸和糖的含量。值得注意的是，过表达植物中 Cd 和干旱诱导的氧化应激明显减弱，表现在胁迫条件下丙二醛和过氧化氢积累减少，以及酶抗氧化剂的活性和转录丰度增加。我们的研究结果提供了确凿的证据，表明番茄中过表达基因正向调控对 Cd 和干旱胁迫的耐受性，这可能增强了对基因的分子理解，以提高非生物胁迫耐受性。
