为了确定抗性基因Me3介导表达的抗根结线虫相关基因WRKY的种类及其表达特点,以含Me3基因的HDA149辣椒品种为材料,接种南方根结线虫二龄幼虫,通过同源克隆法获得辣椒4个WRKY新基因片段。利用RT—PCR技术克隆了WRKY-a、WRKY-b、WRKY-c、CaWRKY1、WRKY1和CaWRRY2等6个WRKY基因的全长cDNA。研究表明,WRKY-a、CaWRKY2基因受根结线虫诱导表达;CaWRKY1基因的表达具有组织特异性,在根和叶中表达,在茎中不表达。聚类分析表明WRKY—a、WRKY—c、CaWRKY2蛋白属于第1组WRKY蛋白,WRKY—b、CaWRKY1属于第Ⅱc亚组,WRKY1属于第Ⅱa亚组。
Pepper cuhivar HDA149 ( Capsicum annuum L. ) is resistant to Meloidogyne incognita, which is controlled by a single dominant gene Me3. To determine the type of WRKY genes and their expression characteristics during the incompatible interaction between HDA149 and Meloidogyne incognita, homology-based cloning and RT-PCR approaches were used in this study. Four new hot pepper WRKY genes were isolated from HDA149 after challenging inoculation with J2 root-knot nematode and the complete eDNAs of six WRKY genes, i.e. WRKY-a, WRKY-b, WRKY-c, CaWRKY1, WRKY1 and CaWRKY2 were amplified. It was shown that the expression of WRKY-a and CaWRKY2 was induced by root-knot nematode. The CaWRKY1 gene expressed differently in various tissues of the plant, e.g. it expressed in roots and leaves but not in stems. Cluster analysis indicated WRKY-a, WRKY-c and CaWRKY2 proteins were clustered into the group Ⅰ of WRKY protein, WRKY-b and CaWRKY1 proteins were classified as subgroup Ⅱ c, whereas WRKY1 protein in subgroup Ⅱ a. WRKY genes regulate HDA149 resistance to root knot nematode together.