青花菜霜霉病响应基因BoiWRKY25的克隆及表达分析OA北大核心CSTPCD

WRKYs are plant-specific transcription factors,play important roles in growth,development,and stress responses.To elucidate the function of BoiWRKY25 in resistance response to downy mildew,in this study,broccoli was used as the material to isolate the gene by PCR method,the gene's function was investigated through gene over-expression based on sequence analysis and expression analysis.The results indicated that BoiWRKY25 had a total length of 1 395 bp,with four introns.The complete coding region of BoiWRKY25 was 1086 bp,encoding a protein of 361 amino acids with a molecular weight of 40.4 kDa and an isoelectric point of 6.98.The grand average hydropathicity of BoiWRKY25 was-0.857,and it was determined as a hydrophilic protein.BoiWRKY25 featured two WRKY domains,each comprising a WRKYGQK heptapeptide and a C2H2-type zinc finger structure.The two zinc finger structures could be represented as C-X4-C-X22-H-X1-H and C-X4-C-X23-H-X1-H,respectively.Expression analysis revealed that BoiWRKY25 was induced by downy mildew,and the highest relative level of expression was observed at 72 h post-inoculation,with a fold change of 4.6 as compared to the control.Over-expression of BoiWRKY25 in broccoli lines reduced the resistance to downy mildew,and the expression levels of the pathogenesis-related protein gene BoiPR1 were significantly down-regulated,indicating BoiWRKY25 plays a negative regulatory role in the resistance response against downy mildew.Isolation and expression analysis of BoiWRKY25 shed light on the mechanism of downy mildew resistance and molecular breeding in broccoli for future research.