PDF(Pubmed)
Abstract：
Salt stress caused by high concentrations of Na+ and Cl- in soil is one of the most important abiotic stresses in agricultural production, which seriously affects grain yield. The alleviation of salt stress through the application of exogenous substances is important for grain production. Melatonin (MT, N-acetyl-5-methoxytryptamine) is an indole-like small molecule that can effectively alleviate the damage caused by adversity stress on crops. Current studies have mainly focused on the effects of MT on the physiology and biochemistry of crops at the seedling stage, with fewer studies on the gene regulatory mechanisms of crops at the germination stage. The aim of this study was to explain the mechanism of MT-induced salt tolerance at physiological, biochemical, and molecular levels and to provide a theoretical basis for the resolution of MT-mediated regulatory mechanisms of plant adaptation to salt stress. In this study, we investigated the germination, physiology, and transcript levels of maize seeds, analyzed the relevant differentially expressed genes (DEGs), and examined salt tolerance-related pathways. The results showed that MT could increase the seed germination rate by 14.28-19.04%, improve seed antioxidant enzyme activities (average increase of 11.61%), and reduce reactive oxygen species accumulation and membrane oxidative damage. In addition, MT was involved in regulating the changes of endogenous hormones during the germination of maize seeds under salt stress. Transcriptome results showed that MT affected the activity of antioxidant enzymes, response to stress, and seed germination-related genes in maize seeds under salt stress and regulated the expression of genes related to starch and sucrose metabolism and phytohormone signal transduction pathways. Taken together, the results indicate that exogenous MT can affect the expression of stress response-related genes in salt-stressed maize seeds, enhance the antioxidant capacity of the seeds, reduce the damage induced by salt stress, and thus promote the germination of maize seeds under salt stress. The results provide a theoretical basis for the MT-mediated regulatory mechanism of plant adaptation to salt stress and screen potential candidate genes for molecular breeding of salt-tolerant maize.
摘要：
土壤中高浓度Na+和Cl-引起的盐胁迫是农业生产中最重要的非生物胁迫之一。严重影响粮食产量。通过施用外源物质缓解盐胁迫对粮食生产具有重要意义。褪黑激素（MT，N-乙酰基-5-甲氧基色胺）是一种吲哚状小分子，可以有效缓解逆境胁迫对作物的损害。目前的研究主要集中在MT对苗期作物生理生化的影响,对作物萌发期基因调控机制的研究较少。这项研究的目的是解释MT诱导的生理耐盐性的机制，生物化学，为解决MT介导的植物适应盐胁迫的调控机制提供理论依据。在这项研究中,我们调查了发芽，生理学,和玉米种子的转录水平，分析了相关的差异表达基因(DEGs)，并检查了耐盐相关途径。结果表明，MT可以使种子发芽率提高14.28-19.04%，提高种子抗氧化酶活性（平均增加11.61%），减少活性氧积累和膜氧化损伤。此外,MT参与调节盐胁迫下玉米种子萌发过程中内源激素的变化。转录组结果表明，MT影响抗氧化酶的活性，对压力的反应，和盐胁迫下玉米种子萌发相关基因的表达，并调节淀粉和蔗糖代谢相关基因的表达和植物激素信号转导途径。一起来看,结果表明，外源MT可以影响盐胁迫玉米种子应激反应相关基因的表达，增强种子的抗氧化能力，减少盐胁迫引起的损伤，从而促进盐胁迫下玉米种子的萌发。研究结果为MT介导的植物适应盐胁迫的调控机制提供了理论依据,为耐盐玉米分子育种筛选潜在的候选基因。
