镉敏感水稻突变体在镉胁迫下活性氧代谢的变化

从粳稻中花11为受体构建的经农杆菌介导的T-DNA插入水稻突变体库中获得了1个对镉敏感的突变体,野生型和突变体经Cd²⁺胁迫表型上有显著差异.结果表明:镉敏感水稻突变体地上部对Cd²⁺吸收与转运速率要快于野生型,膜脂过氧化程度更高;随Cd²⁺胁迫浓度的增加,O₂^·-和H₂O₂在叶片中的积累增加,诱导抗氧化代谢;敏感突变体叶片SOD的抗氧化胁迫能力是有限的,与野生型相比突变体叶片CAT受到更显著的抑制,可能是其对Cd²⁺胁迫更加敏感的生理原因.而叶片G-POD活性整体差异不显著.

Alterations of Oxidative Metabolism Respond to Cadmium Stress in Cd-Sensitive Mutant Rice Seedlings

Cd-sensitive mutant rice(Oryza sativa L.subsp.Japonica,cv.Zhonghua 11) was obtaired using our Agrobacterium tumefaciens based gene derived system.Significant phenotypic differences between a Cd-sensitive mutant(ST) and wild type(WT) rice seedlings by Cd²⁺ treatment was observed.Results indicated the mutant had more intensive capability of cadmium transport in leaf,which leaded to more level of lipid peroxidation than that of the wild type.Furthermore,A rapid Cd-induced O^·-₂ and H₂O₂ increase in the mutant leaves was observed,which induced activity of antioxidant enzymes.The maintaining of SOD activity for resisting stresses in leaves of the mutant was limited in vivo.The CAT activities in leaves of the mutant were more inhibited than that of wild type,which might be a physiological explanation for sensitivity to cadmium in the mutant.However,the difference of the G-POD activities in leaves between the mutant and wild type was not significant.