拟南芥PUB10和PUB11基因抵抗丁香假单胞杆菌番茄致病变种DC3000株的功能分析

Functional Analysis of PUB10 and PUB11 in Arabidopsis thaliana Against the Infection of Pseudomonas syringae DC3000

丁香假单胞杆菌Pseudomonas syringae pv tomato(Pst)DC3000是研究植物免疫机制的常用病原菌。为分析拟南芥E3泛素连接酶PUB10、PUB11在免疫中的功能,本研究构建了pub10/pub11双突变体。在分析拟南芥PUB10、PUB11序列相似性和进化关系的基础上,比较了pub10/pub11双突变体和Col-0对Pst DC3000的敏感性、MAPK磷酸化水平、ROS产生的影响,并检测JA信号响应途径和免疫防御相关的部分代表性基因的表达量。结果表明PUB10、PUB11氨基酸序列高度保守,pub10/pub11双突变体对Pst DC3000的侵染更敏感,侵染后叶片病原菌数目明显增多,MAPK磷酸化水平迅速下降,ROS释放量降低,JA信号响应基因(LOX3,JR2)、免疫防御负调控基因(NIMIN1,WRKY38,WRKY62,RIN4)表达量上升显著高于Col-0,而免疫防御正调控基因(AZI1,EDS1,PAD4,EDS5,FMO1,NPR1)表达量显著低于Col-0。由此推断,AtPUB10、AtPUB11在防御Pst DC3000中起正调控作用,并且存在功能冗余。研究结果为进一步探索PUB10、PUB11调控植物防御的分子作用机制和分子育种提供了依据。

Pseudomonas syringae pv tomato(Pst)DC3000 is a representative pathogen for exploring the immunity mechanism of plant.To analyze the defense function of E3 ubiquitin ligases PUB10 and PUB11 in Arabidopsis thaliana,we established the pub10/pub11 double mutant.After analyzing the sequence similarity and evolutionary relationship of PUB10 and PUB11 in Arabidopsis thaliana,we compared the sensitivity of Pst DC3000 infection,MAPK phosphorylation levels,ROS burst,and detected the expression levels of mark genes involved in JA signal transduction and plant defense between the pub10/pub11 double mutant and wide type plant(Col-0).Results indicated that amino acid sequence of PUB10,PUB11 were highly conserved.pub10/pub11 double mutant was more sensitive to Pst DC3000 infection which showed by leaf pathogens increased significantly after infection than Col-0.In the pub10/pub11,MAPK phosphorylation levels decreased more rapidly after stimulation by Pst DC3000,and the ROS burst was decreased.Further,JA signal response genes(LOX3,JR2),and immune defense negative regulatory genes(NIMIN1,WRKY38,WRKY62,RIN4)in the pub10/pub11 double mutant expression levels increased obviously more than Col-0,while immune defense positive regulatory genes(AZI1,EDS1,PAD4,EDS5,FMO1,NPR1)expression levels increased obviously less than Col-0.These results suggested that AtPUB10 and AtPUB11 have functional redundancy and play a positive regulatory role in the defense of Pst DC3000,which could provide some helpful information for further exploring the molecular mechanism of plant defense and molecular breeding involved about PUB10 and PUB11.