水杨酸对干旱胁迫下小麦幼苗抗氧化特性的影响

为了给水杨酸在小麦栽培中的应用提供参考依据,以小麦品种百农AK58为材料,用17.5%聚乙二醇6000(PEG6000)模拟干旱胁迫,研究了外源水杨酸对干旱胁迫下小麦幼苗叶片和根系抗氧化特性的影响。结果表明,干旱胁迫显著提高了根、叶细胞质膜透性、丙二醛(MDA)含量及过氧化物岐化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)等抗氧化酶活性。与单独干旱胁迫处理相比,外源施加水杨酸可使干旱下小麦幼苗根系APX、POD、SOD和CAT活性分别增加190.9%、20.4%、42.3%和89.4%,使其膜透性和MDA含量分别降低19.7%和54.6%;对叶片而言,水杨酸可使其APX和POD活性分别增加31.5%和159.6%,使其膜透性和MDA含量分别降低23.7%和53.9%。上述结果说明,干旱胁迫加剧了小麦的氧化胁迫,小麦幼苗则通过增强根、叶抗氧化酶活性以抵抗氧化伤害。外源施加水杨酸可增强小麦幼苗根、叶相关抗氧化酶的活性,从而缓解小麦在干旱下所遭受的氧化伤害,增强其抗旱性。

Effects of Exogenous Salicylic Acid on Antioxidant Properties of Wheat Seedling under Drought Stress

In order to provide scientific evidence for the application of salicylic acid in the production and cultivation of wheat,the effects of exogenous salicylic acid on antioxidant properties of AK58 seedling under drought stress were investigated. The results showed that the membrane permeability,malondialdehyde (MDA) content and the activities of superoxide dismutase (SOD),catalase (CAT) and ascorbate peroxidase (APX) in leaf and root were significantly increased under drought stress. Compared with drought stress alone,exogenous salicylic acid could increase the activities of APX,peroxidase (POD),SOD and CAT in root of BainongAK58 by 190.9%,20.4%,42.3% and 89.4%,respectively. Exogenous salicylic acid could reduce the membrane permeability and MDA content in root of BainongAK58 by 19.7% and 54.6%,respectively. For the leaves,exogenous salicylic acid could increase the activities of APX and POD by 31.5% and 159.6%,respectively. Exogenous salicylic acid could reduce the membrane permeability and MDA content in leaves of BainongAK58 by 23.7% and 53.9%,respectively. Above results suggested that drought stress could induce oxidative stress in Bainong AK58 seedling. Meanwhile, Bainong AK58 could protect itself against stress by enhancing the activities of antioxidant enzymes. Mean while,application of exogenous salicylic acid could protect Bainong AK58 against the oxidative injury induced by drought stress by improving the activities of related antioxidant enzymes in root and leave of seedlings.