摘要： 以转gshⅠ基因拟南芥为试验材料,测定干旱胁迫下转基因植株的gsh含量、MDA含量和相对电导率,同时测定谷胱甘肽还原酶(GR)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性,研究酵母gsh I基因的功能,分析转基因拟南芥的抗旱生理机制。结果表明:干旱胁迫下,转基因植株和对照的gsh含量都有所增加,但转基因植株增加更多,干旱诱导了对照和转基因植株gsh的合成,gsh I基因的表达提高了转基因植株中合成gsh的水平。转基因植株中GR活性比对照的高得多,提高了gsh/GSSG比率,使氧化态gsh得到还原,干旱启动了gsh的再生系统。转基因植株叶片相对含水量变化不明显(与对照相比),但MDA含量和相对电导率增加幅度均低于对照植株,转基因植株提高了膜系统的稳定性(抗氧化作用)。干旱胁迫下,对照和转基因植株SOD和CAT活性均下降,但没有明显差异,表明gsh与SOD、CAT对活性氧的清除机制不同。

关键词: gsh I基因, 拟南芥, 转基因, 耐旱性, 生理生化指标

Abstract: Using the transgenic gsh I gene Arabidopsis thaliana as materials,the contents of gsh and MDA,the electrolyte leakage(EL) and the activities of GR,SOD and CAT in the transgenic plants were measured to study the function of gsh I gene and analyze physiological mechanisms of transgenic Arabidopsis thaliana. The contents of gsh increased in both transgenic and control plants when the plants were subjected to drying treatment,however, the gsh production rate was higher in transgenic plants than that in control plants. gsh synthesis is induced in both transgenic and control plants with drougth stress,but the gsh I gene expression in the transgenic plants enhanced gsh synthesis level. The activity of GR in transgenic plants was higher than that in control plants. GR activity increases leads to a higher ratios of gsh to GSSG in transgenic plants and oxidative gsh is reduced. gsh regeneration system is launched with drougth stress. The leaves water content did not show obvious differences in changes between the transgenic and control plants with drougth stress. However,the MDA contents and electrolyte leakage(EL)(Conductivity) increased in both transgenic and control plants,but those of the transgenic plants was slower than those of control plants. The transgenic plants improved the stability of the membrane system(Antioxidation). The activities of SOD and CAT decreased in both transgenic and control plants,but did not show obvious differences. gsh is different from SOD and CAT in eliminating ROS.

Key words: gsh I gene, Arabadopsas thalaana, Transgene, Drought tolerance, Physiological and biochemical index

中图分类号: 

• Q78