【摘要】 以拟南芥uvr8-2突变体植株为材料,研究UV-B预处理对植株响应干旱胁迫的影响以及植物激素在此过程中的作用.实验结果表明:从形态观察到生理指标,UV-B预处理显著提高了拟南芥uvr8-2突变体的干旱适应性,与野生型Ler的结果一致; UV-B预处理显著提高了拟南芥uvr8-2突变体抗氧化酶SOD、POD、CAT活性,抗氧化酶基因POD和CAT的表达量,以及植物激素ABA、JA、SA的质量分数,降低了细胞膜受损程度.由此推测:UV-B预处理诱导uvr8-2植株的干旱适应性中存在一条不依赖于UVR8的信号转导途径,即通过增加植物逆境响应激素ABA、JA和SA的质量分数,调控抗氧化酶基因CAT和POD表达和增强抗氧化酶活性,从而缓解干旱胁迫下拟南芥的叶片萎焉、相对含水量下降等现象.更多还原

【Abstract】 The effect of UV-B pretreatment on the drought response of Arabidopsis thaliana uvr8-2 mutants and the role of plant hormones in this process were investigated. The following results were obtained. Both morphological observation and physiological indicators showed that UV-B pretreatment significantly improved the drought adaptability of uvr8-2 mutants,which was consistent with the result of research on wild-type Landsberg erecta( Ler). The activities of antioxidant enzymes( SOD,POD,and CAT) were significantly increased upon UV-B pretreatment in Arabidopsis uvr8-2 mutants. The expression of antioxidant enzyme genes( POD and CAT) and the levels of plant hormones( ABA,JA and SA) also were increased. In addition,the degree of cell membrane damage was reduced.The fact that UV-B pretreatment induced the drought adaptability of uvr8-2 mutant implies that the signaling involved in the process is UVR8-independent,namely,the UV-B pretreatment induced drought adaptability by increasing plant hormones such as ABA,JA and SA to enhance the activity of antioxidant enzymes and antioxidant enzyme genes CAT and POD so as to alleviate the withering of leaves and the decreasing of relative water content under drought stress.更多还原