Cd2+胁迫对番茄幼苗抗坏血酸-谷胱甘肽循环代谢的影响

通过温室水培试验，研究0．05mmol／L Cd^2 胁迫及解除Cd^2 胁迫对番茄幼苗根系和叶片中抗坏血酸-谷胱甘肽(AsA—GSH)循环代谢的动态影响。结果表明，胁迫条件下，番茄根系和叶片中脂质过氧化产物-丙二醛(MDA)含量增加，细胞膜受损伤；抗坏血酸过氧化酶(APX)活性在胁迫1，3d上升，随后下降，而谷胱甘肽还原酶(GR)活性在胁迫1d时下降，随后上升；抗坏血酸(AsA)和谷胱甘肽(GSH)含量上升，且根系上升幅度大于叶片；解除胁迫后，叶片中MDA含量随时间延长逐渐减少，接近对照，而根系中MDA含量持续上升。APX、GR活性和AsA、GSH含量都能够渐渐恢复，但仍高于对照，根系中GSH含量持续维持较高水平，叶片和根系各参数的恢复程度有差异．

Effects of Cd2 + Stress on Ascorbate-Glutathione Cycle Metabolism in Tomato Seedlings

A solution culture experiment in greenhouse was carried out to study the dynamic change of ascorbate-glutathione cycle metabolism in roots and leaves of tomato seedlings under 0.05 mmol/L Cd~(2+) stress and recovery. The results showed that under stress malonaldehyde(MDA) contents in roots and leaves increased ,ascorbate peroxidase(APX)activity rose at the begining of three days and then decreased ,glutathione reductase(GR) activity decreased on the first day and then increased, the content of ascrobate(AsA) and glutathione(GSH) increased and the increase in roots was higher than that of leaves. After recovery the MDA content in leaves declined to control level, while the MDA content in roots duratively increased. The activities of APX and GR and the content of AsA and GSH could recover, which were higher than control. GSH contents in roots duratively maintain high level. There were defferences between the resumptive extent of parameters of leaves and roots.