普通菜豆中烟草水杨酸结合蛋白2同源基因的鉴定及表达特征分析

水杨酸(salicylic acid, SA)能够诱导植物产生系统抗病性反应, 而水杨酸结合蛋白2 (salicylic acid binding protein 2, SABP2)是植物细胞内调控水杨酸水平的重要酯酶。本研究利用生物信息学方法在普通菜豆中搜索到7个烟草水杨酸结合蛋白2的同源基因, 命名为PvMES1~PvMES7。分别在2个菜豆感病品种(白刀豆和BRB130)和2个抗病品种(黑芸豆和260205)中接种尖镰孢菌FOP-DM01菌株(Fusarium oxysporum f. sp. phaseoli isolate, FOP-DM01)后, 检测寄主根组织中水解水杨酰甲酯(methyl salicylate, MeSA)活性和游离SA含量的变化, 并利用荧光定量PCR技术分析7个PvMES基因表达量变化。结果表明, PvMES1、PvMES3、PvMES4、PvMES5和PvMES6的转录表达受FOP-DM01菌株诱导均呈现不同程度的升高, 其中黑芸豆中PvMES5基因和260205中PvMES1基因表达量变化最显著, 接种3 d后分别升高至0 d表达量的7.6倍和5.6倍。此外, 黑芸豆和260205根中水杨酰甲酯酯酶(methyl salicylate esterase, MES)活性显著提升, 游离SA含量也相应升高, 激活寄主内SA介导的相关防御反应。本研究结果可以为普通菜豆镰孢菌枯萎病抗病分子育种和抗病机理研究提供理论基础。

Identification and Expression Analysis of Likely Orthologs of Tobacco Salicylic Acid Binding Protein 2 in Common Beans

Salicylic acid can induce the systematic resistant response in plants, and salicylic acid-binding protein 2 is an important esterase in the regulation of salicylic acid content in plant cells. In this study, we used the bioinformatics method to search the orthologous genes of tobacco salicylic acid-binding protein 2 in common bean, which were designated as PvMES1-PvMES7, then analyzed the changes of MES activity and free SA accumulation in plant roots. The expression level of 7 PvMES genes in susceptible varieties BRB130 and Baidaodou, resistant varieties Heiyundou and 260205 infected by Fusarium oxysporum f. sp. phaseoli isolate FOP-DM01 was detected by Real time PCR, showing that the expression of PvMES1, PvMES3, PvMES4, PvMES5, and PvMES6 was significantly increased at three days after FOP-DM01 infection, with most significant increase of 7.6 folds and 5.6 folds for PvMES5 gene in Heiyundou and PvMES1 gene in 260205 at 0 day, respectively. The MES activity and free SA content in roots of Heiyundou and 260205 were also improved, which activated the relevant defense response reaction mediated by SA in the host. The results of this study provide a theoretical basis for the resistance molecular breeding of Fusarium wilt in common beans.