外源柠檬酸对铝胁迫栝楼抗氧化酶系及根尖铝积累的影响

Effects of Exogenous Citrate on Leaf Antioxidase System and Root Tip Al^(3+) Accumulation of Trichosanthes kirilowii Seedlings under Al^(3+) Stress

探明有机酸缓解植物铝毒害的机理,为栝楼在南方红壤地区的推广种植提供理论依据。以栝楼幼苗为实验材料,探究外源柠檬酸对铝胁迫下栝楼生理变化及根尖铝含量的影响。结果表明:在同一浓度Al^(3+)胁迫下,超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性均随柠檬酸含量升高而增大;过氧化物酶(POD)活性在低浓度Al^(3+)胁迫时,随柠檬酸浓度增加呈先上升后下降趋势;Al^(3+)浓度为800μmol/L时对栝楼酶活性有抑制作用;随着Al^(3+)胁迫时间延长及浓度增加,栝楼根尖相对铝含量明显增加,加入柠檬酸后栝楼根尖的铝积累量有所减少。

The effects of exogenous citrate on physiological variation and root tip Al^（3＋）content of Trichosanthes kirilowii seedlings under Al^（3＋）stress were studied to explore the mechanism of organic acid relieving plant Al^（3＋）toxicity and to provide the theoretical basis for cultivation of T.kirilowii in red soil region of South China.Results：The SOD and CAT activity increases with increase of citrate content under the same Al^（3＋）concentration stress.The POD activity presents a first rising and then declining trend with increase of citrate content under the lower Al^（3＋）concentration stress.when Al^（3＋）cotentration in 800μmol/L,the enzyme activity of T.kirilowii is inhibited.The relative Al^（3＋）content of T.kirilowii root tips is significantly increased with time extension of Al^（3＋）stress and increase of Al^（3＋）concentration but adding citrate can decrease Al^（3＋）accumulation of T.kirilowii root tips.