Abstract: In order to investigate the effect of ascorbic acid （AsA） priming on the mitochondrial antioxidant capacity of oat seedlings under salt stress, oat （Avena sativa） seeds were used as materials for this experiment, which was primed with different concentrations of AsA （0, 1, 2, 4 mmol·L^-1） for 24 h, and the germination test was carried out under different concentrations （0, 75, 150 mmol·L^-1） of NaCl stress, then the changes in antioxidant enzyme activities and the level of lipid peroxidation were measured in the oat seedlings germinated for 10th days. The results showed that priming with AsA increased the activities of antioxidant enzymes in mitochondria of oat seedlings under salt stress comparing with CK, and this effect was closely related to the concentration of AsA and salt. In this experiment, priming with 1 mmol·L^-1 AsA was the optimal treatment for oat seedling to improve the antioxidant performance in mitochondria under 75 mmol·L^-1 NaCl stress, and the activities of superoxide dismutase （SOD）, catalase （CAT）, ascorbate peroxidase （APX）, monodehydroascorbate reductase （MDHAR）, dehydroascorbate reductase （DHAR） and glutathione reductase （GR） reached the maximum, which were 7.50 U·mg^-1,0.30 U·min^-1·g^-1,1.09 U·min^-1·g^-1,0.20 U·min^-1·mg^-1,0.12 U ·min^-1·mg^-1,1.13 U·min^-1·g^-1, respectively, but the contents of H₂O₂ and malondialdehyde （MDA） were also the lowest level of 253.99 mmol·g^-1 and 0.02 μmol·mg^-1, respectively.

Key words: Ascorbic acid, Seed priming, Salt stress, Oat, Oxidation resistance

摘要： 为探讨盐胁迫下抗坏血酸（Ascorbic acid,AsA）引发对燕麦（Avena sativa）幼苗线粒体抗氧化能力的影响,本试验以燕麦种子为材料,在不同浓度（0,1,2,4 mmol·L^-1）的AsA溶液中引发处理24 h后,在浓度为0,75,150 mmol·L^-1的NaCl胁迫下进行标准发芽试验,并取发芽第10 d的燕麦幼苗来测定其抗氧化酶活性及脂质过氧化水平的变化规律。结果表明：与未引发种子（CK）相比,AsA引发能够提高盐胁迫下燕麦幼苗线粒体抗氧化酶活性,且AsA浓度和盐胁迫浓度对燕麦幼苗线粒体的抗氧化性能均有影响,本试验中75 mmol·L^-1的NaCl胁迫下施用1 mmol·L^-1 AsA时,其超氧化物歧化酶、过氧化氢酶、抗坏血酸过氧化物酶、单脱氢抗坏血酸还原酶、脱氢抗坏血酸还原酶、谷胱甘肽还原酶活性均达到最大值,分别为7.50 U·mg^-1,0.30 U·min^-1·g^-1,1.09 U·min^-1·g^-1,0.20 U·min^-1·mg^-1,0.12 U·min^-1·mg^-1,1.13 U·min^-1·g^-1,且H₂O₂和丙二醛含量也最低,分别为253.99 mmol·g^-1,0.02 μmol·mg^-1,因而是提高燕麦幼苗线粒体抗氧化性能的最佳处理。

关键词: 抗坏血酸, 种子引发, 盐胁迫, 燕麦, 抗氧化性能