玉米ZmBT2b基因在抵抗禾谷镰孢侵染中的功能研究

Function of ZmBT2b gene in maize resistance to Fusarium graminearum

为探究玉米BTB-TAZ蛋白ZmBT2b在玉米抵抗病原菌侵染过程中的功能,本研究利用生物信息学技术对ZmBT2b基因进行了系统分析,确定了ZmBT2b具有BTB和TAZ结构域,具有明显的组织表达特性,在生物和非生物胁迫下呈现不同的表达规律。通过构建ZmBT2b基因过表达的拟南芥植株ZmBT2b-OE,对该基因在植物抗病过程中的功能进行研究,结果发现ZmBT2b-OE对灰葡萄孢和Pst.DC3000的抗性显著增强,确定了ZmBT2b基因在植物抗病过程中具有重要功能。为明确ZmBT2b基因在玉米抵抗禾谷镰孢侵染过程中的功能,本研究获得了该基因的玉米突变体Zmbt2b-1和Zmbt2b-2,对突变体的抗病性进行检测发现,突变体Zmbt2b-1和Zmbt2b-2对禾谷镰孢的抗性敏感性显著高于野生型,且突变体中JA合成途径关键合成基因ZmLOXs和病程相关基因ZmPRs在禾谷镰孢侵染过程中显著下调,表明ZmBT2b在玉米抗禾谷镰孢侵染过程中具有正调控功能。研究结果为阐明玉米BTB-TAZ蛋白在玉米抗病过程中的功能及其调控机制奠定了基础,为玉米抗病育种提供了基因资源。

In order to investigate the function of the maize BTB-TAZ protein ZmBT2b in maize resistance to pathogenic fungal infection,the ZmBT2b gene was systematically analyzed using bioinformatics techniques in this study.It was determined that ZmBT2b has both BTB and TAZ structural domains.It showed obvious tissue specific expression and different expression patterns under biotic and abiotic stresses.By constructing ZmBT2b gene overexpressing Arabidopsis thaliana plants ZmBT2b-OE,the function of this gene in the process of plant disease resistance was investigated.ZmBT2b-OE plants showed significantly enhanced resistance to Botrytis cinerea and Pst.DC3000,suggesting its function in the process of plant disease resistance.In order to clarify the function of ZmBT2b gene in the process of maize resistance to Fusarium graminearum infestation,maize mutants Zmbt2b-1 and Zmbt2b-2 of this gene were obtained whose disease resistance of were tested.It was found that the F.graminearum resistance was significantly higher in mutants Zmbt2b-1 and Zmbt2b-2 than that of the wild type.The expression of ZmLOXs in JA synthesis pathway and ZmPRs as disease course-related genes were significantly down-regulated during F.graminearum infestation,indicating that ZmBT2b has a positive regulatory function in maize resistance to F.graminearum infestation.The results laid the foundation for elucidating the function of maize BTB-TAZ protein and its regulatory mechanism in the process of maize disease resistance,and provided genetic resources for maize disease resistance breeding.