镉对镉超累积植物龙葵抗氧化酶活性及基因表达的影响

Effects of Cd on activity and gene expression of antioxidant enzymes in hyperaccumulator Solanum nigrum L

6周大的龙葵幼苗在30～100μmol/L CdCl2溶液中胁迫0～72 h,叶和根SOD、POD、CAT和APX活性均随Cd浓度的提高和胁迫时间的延长而上升.实时定量PCR分析表明,100μmol/L CdCl2胁迫上调幼苗叶FSD1、CSD2、POD2和CAT2与根FSD1、CSD2、POD1和APX3的转录,下调叶POD1和CAT1与根CSD1、MSD1和CAT1的转录,而对叶CSD1、MSD1、APX1和APX3与根POD2、CAT2和APX1的表达水平无明显影响.这些结果表明Cd可增强或稳定多种抗氧化酶基因的转录水平或转录后水平的调节,提高酶活性.

The 6-week-old for 0-72 h. It was detected seedlings of Solanum nigrum L. were treated with 30-100 I^mol/L CdC12 that the total activities of SOD, POD, CAT, and APX in leaf and root were obviously enhanced with increased Cd concentration and prolonged Cd treatment. Real-time quantitative PCR showed that the transcripts of FSD1, CSD2, POD2, and CAT2 in leaf or FSD1, CSD2, POD1, and APX3 in root were up-regulated and the mRNAs of POD1 and CAT1 in leaf or CSD1, MSD1, and CAT1 in root were down-regulated, while no changes in the transcripts of CSD1, MSD1, APX1, and APX3 in leaf or POD2, CAT2, and APX1 in root were detected. The results indicate that the element Cd enhances or maintain the transcription level of antioxidant enzyme genes or regulates the post-transcriptional level, and it increases the enzyme activity.