论文部分内容阅读
为了探究外源甜菜碱对干旱胁迫下小麦幼苗的生长调节作用,以优质高产、高抗旱的小麦品种矮抗58为材料,四叶期分别用0.1、1.0和10.0mmolL?1的GB预处理小麦叶片,同时在根部施加30%聚乙二醇(PEG-6000)以模拟干旱环境,研究其对小麦超氧化物歧化酶(SOD),过氧化氢酶(CAT),过氧化物酶(POD),丙二醛(MDA)、超氧阴离子自由基(O???)产生速率、叶绿素含量及相对含水量的影响,并采用Real-timePCR测定叶绿体psbA基因表达水平的变化。结果表明,干旱胁迫明显减少小麦叶片相对含水量和叶绿素含量,降低SOD、CAT及POD活性,提升MDA含量和O???产生速率,抑制psbA基因表达水平,而外施GB具一定浓度效应,在适当浓度下能明显缓解这些胁迫反应,调控干旱胁迫下小麦叶绿体抗氧化酶活性以清除多余活性氧,减缓相对含水量及叶绿素含量的降低,提升psbA基因的表达水平,从而加快受损D1蛋白的周转并提高小麦的抗干旱胁迫能力。
In order to explore the regulatory effect of exogenous betaine on the growth of wheat seedlings under drought stress, the high-yielding and drought-resistant wheat variety Aikang 58 was used as the material, and the four-leaf stage was pretreated with 0.1, 1.0 and 10.0 mmol L -1 GB Leaf, at the same time, 30% polyethylene glycol (PEG-6000) was applied to the roots to simulate the drought environment and its effects on the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) , Malondialdehyde (MDA), superoxide anion radical (O) production rate, chlorophyll content and relative water content. The changes of chloroplast psbA gene expression level were measured by Real-time PCR. The results showed that drought stress significantly reduced the relative water content and chlorophyll content of wheat leaves, decreased the activities of SOD, CAT and POD, increased the content of MDA and the production rate of O ??? and inhibited the expression of psbA gene, while the external application of GB had a certain concentration effect, Under appropriate concentration, these stress responses were significantly alleviated, and the antioxidant enzyme activities of wheat chloroplast under drought stress were scavenging to remove excess ROS, slowing the decrease of relative water content and chlorophyll content, increasing the expression of psbA gene and accelerating the damage of D1 protein Turnover and increase drought-resistant ability of wheat.