柠檬酸对铝胁迫下大豆根系生长和生理特性的影响

摘要

We studied the effects of citric acid on growth and physiological characteristics of soybean ( Glycine max L.) seedlings under the aluminum stress. Under the aluminum stress, root length,root fresh weight, SOD activity and root activity of soybean significantly reduced ( 58�2%, 40�6%, 33�2%, and 50�6% lower than that of the control, respectively ) , whereas MDA content and relative conductivity significantly increased(50�7%,and 50�6% higher than that of the control,respectively). After citric acid treatment, root length,root fresh weight,SOD activity and root activity of soybean significantly increased (85�6%,34�4%,44�8%,and 81�3% higher than under aluminum stress, respectively); MDA content and relative conductivity significantly reduced after citric acid treatment ( 26�7%,and 30�3% lower than under aluminum stress, respectively ) . The optimum concentration of citric acid for root length was 15μmol/L,and that for other indicators was 20 μmol/L. Crtric acid can reduce the damage of soybean seedlings under aluminum stress.%以大豆（Glycine max L．）幼苗为材料，研究柠檬酸处理对铝胁迫下，大豆根系生长和生理特性的影响。结果表明：与对照（ CK）相比，在铝胁迫下，大豆根系长度、根系鲜质量、超氧化歧化酶（ SOD）活性和根系活力等分别降低58�2％、40�6％、33�2％和50�6％，丙二醛（ MDA）含量和相对电导率分别增加50�7％和50�6％。与单纯铝胁迫处理相比，加入柠檬酸后，大豆幼苗根系长度、根系鲜质量、SOD活性和根系活力等分别比铝胁迫处理提高85�6％、34�4％、44�8％和81�3％，MDA含量和相对电导率分别比铝胁迫处理降低26�7％和30�3％。柠檬酸缓解根系长度的最佳处理浓度为15μmol／L，缓解其他指标的最佳浓度均为20μmol／L。柠檬酸可降低铝对大豆根系的损伤。