论文部分内容阅读
采用水培试验,研究了0.5 mg·L~(-1) Cd胁迫下添加10μmol·L~(-1)吲哚-3-乙酸(IAA)、吲哚丁酸(IBA)和萘乙酸(NAA)3种外源生长素对玉米幼苗生长、镉吸收、丙二醛(MDA)、脯氨酸(Pro)和谷胱甘肽(GSH)含量及抗氧化酶活性的影响。结果表明,镉胁迫下,IAA和IBA能显著提高玉米幼苗根和地上部生物量,显著降低叶片MDA和GSH含量,IAA使玉米幼苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性显著提高,但IBA和NAA使上述3种酶活性显著降低。IAA对玉米幼苗根镉含量的影响不显著,却使地上部镉含量显著降低,IBA使玉米幼苗根和地上部镉含量均显著提高。NAA使玉米幼苗根和地上部的生物量、镉含量、GSH含量和3种酶活性显著降低,使玉米幼苗叶片MDA显著提高。3种外源生长素均可提高玉米幼苗叶片脯氨酸含量。说明10μmol·L~(-1)不同外源生长素对玉米幼苗生长及抗氧化系统的影响不同。IAA和IBA可通过减轻膜脂过氧化程度来缓解镉对玉米幼苗的伤害,而NAA却加剧了玉米幼苗受到的伤害。相关分析显示,玉米幼苗叶片MDA含量与3种酶活性及Pro含量的相关性不显著,但与GSH含量显著相关,表明GSH在镉胁迫下玉米幼苗抗氧化系统中起作十分重要的作用。
A hydroponic experiment was conducted to study the effects of IAA, IBA and NAA on the growth of seedlings exposed to 0.5 mg · L -1 cadmium stress. Effects of Three Exogenous Auxins on Growth, Cadmium Uptake, Contents of Malondialdehyde (MDA), Pro and Glutathione (GSH) and Activity of Antioxidant Enzymes in Maize Seedlings. The results showed that under cadmium stress, IAA and IBA could significantly increase the biomass of roots and shoots of corn seedlings and significantly reduce the content of MDA and GSH in leaves. The contents of superoxide dismutase (SOD), peroxidase (POD) ) And catalase (CAT) activity increased significantly, but IBA and NAA significantly reduced the activity of the above three enzymes. IAA had no significant effect on the Cd content of maize seedling roots, but significantly decreased the Cd content in aboveground parts of maize seedlings. IBA significantly increased the Cd contents in roots and shoots of maize seedlings. NAA significantly reduced the biomass, cadmium content, GSH content and three enzyme activities in the roots and shoots of maize seedlings, and significantly increased MDA in maize seedling leaves. Three kinds of exogenous auxin can increase the proline content of maize seedling leaves. The results showed that 10μmol·L -1 different auxin had different effects on the growth and antioxidant system of maize seedlings. IAA and IBA can alleviate the harm of cadmium to corn seedlings by reducing the degree of lipid peroxidation, while NAA exacerbates the damage of corn seedlings. Correlation analysis showed that there was no significant correlation between the content of MDA and the content of Pro and the content of GSH in the leaves of maize seedlings, indicating that GSH play a very important role in the antioxidant system of maize seedlings under cadmium stress.