自然干旱胁迫下IrrE基因对甘蓝型油菜生理生化变化的影响

Effect of IrrE Expression on the Physiology and Antioxidant Enzymes in Brassica napus L. under Natural Drought Stress

摘要: 以转IrrE基因与非转基因甘蓝型油菜为材料，在自然干旱条件下，比较研究了转基因与非转基因油菜植株的干旱耐受性情况。结果表明，在0-35 d的自然干旱情况下，随着盆土中土壤含水量的逐渐降低，转基因与非转基因油菜植株的叶片含水量(RWC)也逐渐下降，35 d后他们的含水量降到最低，恢复供水后，其含量均逐渐上升。而油菜叶片的叶绿素含量、可溶性蛋白含量、丙二醛(MDA)含量、SOD和POD酶活性却逐渐上升，恢复供水后，他们的含量和酶活性均逐渐下降，但在干旱胁迫和复水过程中，转基因油菜叶片的含水量、叶绿素含量、可溶性蛋白含量、SOD和POD酶活性均高于非转基因油菜，而丙二醛(MDA)含量始终低于非转基因的含量。说明来源于耐辐射奇球菌的转录调节因子IrrE，参与了油菜幼苗对干旱胁迫的耐受性应答过程，从而增强了植株的耐旱能力。

Abstract: The tolerant responses to drought stress in IrrE-transgenic Brassica napus L. and non-transgenic Brassica napus L. were studied. The results showed that water content in IrrE-transgenic and non-transgenic leaves of rapeseed gradually decreased with the drop of soil water content in pots during 0 - 35 d and their contents reached the minimum value after 35 d under natural drought conditions and then increased gradually after the restoration of water supply. The content of chlorophyll, soluble protein and malondialdehyde (MDA), and the SOD and POD activity in leaves of Brassica napus L. were increased gradually during 0 - 35 d and their contents reached the maximal value after 35 d under natural drought conditions and then decreased gradually after the restoration of water supply. But the water content, chlorophyll content, soluble protein content and the activity of peroxidase (POD) and superoxide dismutase (SOD) in leaves of transgenic Brassica napus L were higher than those in non-transgenic Brassica napus L., while the content of ma-lonaldehyde (MDA) in transgenic Brassica napus L. was lower than non-transgenic Brassica napus L. during 0 - 35 d under drought stress and the restoration of water supply. Therefore, the results from above indicated that IrrE as the transcription regulation factor, which was derived from the radiation resistant bacteria, was involved in the tolerance response of rape seedling to drought stress, and then enhanced the ability of drought tolerance.