摘要
A rice cadmium （Cd） sensitive mutant cadB-1 was obtained using Agrobacterium tumefaciens mediated system.After exposure of cadB-1 and wild type （WT） rice seedlings to a range of Cd concentrations for 10 d,Cd accumulated to higher levels in roots,stems and leaves of both cadB-1 and WT with increasing external Cd concentrations,and the inhibition of seedling growth in cadB-1 was more serious than in WT.Hydrogen peroxide accumulation was higher in leaves and roots of cadB-1.The ratios of reduced glutathione （GSH）/oxidized glutathione （GSSG）,ascorbate （ASC）/dehydroascorbate （DHA） and reduced nicotinamide adenine dinucleotide phosphate （NADPH）/oxidized nicotinamide adenine dinucleotide phosphate （NADP＋） were lower in cadB-1 than in WT both in leaves and roots under high Cd levels.The activities of ascorbate peroxidase （APX）,glutathione peroxidase （GR）,dehydroascorbate reductase （DHAR） and monodehydroascorbate reductase （MDHAR） were also lower in cadB-1 than in WT both in leaves and roots under the treatment of high levels of Cd.Our results suggest that under Cd stress,the ASC-GSH cycle was more seriously inhibited in cadB-1 than in WT,indicating that the mutant cadB-1 is less able to scavenge reactive oxygen species and sensitive to Cd.
A rice cadmium （Cd） sensitive mutant cadB-1 was obtained using Agrobacterium tumefaciens mediated system.After exposure of cadB-1 and wild type （WT） rice seedlings to a range of Cd concentrations for 10 d,Cd accumulated to higher levels in roots,stems and leaves of both cadB-1 and WT with increasing external Cd concentrations,and the inhibition of seedling growth in cadB-1 was more serious than in WT.Hydrogen peroxide accumulation was higher in leaves and roots of cadB-1.The ratios of reduced glutathione （GSH）/oxidized glutathione （GSSG）,ascorbate （ASC）/dehydroascorbate （DHA） and reduced nicotinamide adenine dinucleotide phosphate （NADPH）/oxidized nicotinamide adenine dinucleotide phosphate （NADP＋） were lower in cadB-1 than in WT both in leaves and roots under high Cd levels.The activities of ascorbate peroxidase （APX）,glutathione peroxidase （GR）,dehydroascorbate reductase （DHAR） and monodehydroascorbate reductase （MDHAR） were also lower in cadB-1 than in WT both in leaves and roots under the treatment of high levels of Cd.Our results suggest that under Cd stress,the ASC-GSH cycle was more seriously inhibited in cadB-1 than in WT,indicating that the mutant cadB-1 is less able to scavenge reactive oxygen species and sensitive to Cd.
基金
supported by the grants from Zhejiang Gongshang University,China(Grant No.1110KU111008)
the National Science Foundation of China(Grant No.20977084)
