小麦TaXI-Ⅲ基因转录调控因子的筛选及其与TaWRKY33互作的验证OA

The Triticum aestivum xylanase inhibitors(TaXIs)can suppress the enzymatic activity of the GH11 family xylanase from Fusarium graminearum and its induced cell necrosis,but the transcriptional regulatory mechanism of XIs remains unclear.In this study,the promoter sequence of the TaXI-Ⅲ gene was cloned from wheat cultivar'Annong 1589',and its cis-acting elements were analyzed by PlantCARE database.The TaXI-Ⅲpromoter fragment was used as bait to screen the interacting transcription factors by yeast one-hybrid(Y1H)assay,and the binding specificity between transcription factors and promoter was confirmed by point-to-point Y1H,dual-luciferase reporter system,and GUS histochemical staining.The results showed that the promoter sequence of 2 138 bp upstream of TaXI-Ⅲ gene was cloned successfully,which contained cis-acting elements such as jasmonic acid response,biological/abiotic stress response,MYB and MYC binding sites.Four transcription factors were screened from wheat cDNA library with pHis-TaXI-Ⅲpro as bait vector and 120 mmol/L 3-amino-1,2,4-triazole(3-AT)as selective agent,they were TaMYB30,TaPIEP1,TaTGA1a and TaWRKY33.Among them,TaWRKY33 was verified to bind to the W-box within the TaXI-Ⅲ promoter and regulate its expression.qPCR analysis revealed a co-expression pattern for TaWRKY33 and TaXI-Ⅲ under methyl jasmonate and F.graminearum treatment.Furthermore,overexpression of TaWRKY33 in Arabidopsis thaliana enhanced plant resistance to F.graminearum.These results indicated that TaWRKY33 might enhance resistance to F.graminearum by binding to the W-box in the TaXI-Ⅲ promoter and activating gene expression through the jasmonic acid signaling pathway.This study provides important reference information for further elucidating the transcriptional regulatory mechanism of the TaXI-Ⅲ gene.