枝孢菌SYC23中重寄生相关转录因子基因挖掘及表达分析OA

[Objective]Identification of MYB and bHLH family genes associated with the mycoparasitism of Cladosporium anthropo-philum SYC23 and clarification on their numbers and roles in the mycoparasitic process were carried out,to provide a theoretical ba-sis for further research on the mycoparasitic mechanism of strain SYC23.[Method]Bioinformatics methods were applied to identify and analyze the genes of transcription factors MYB and bHLH families in the genome of strain SYC23,and then RT-qPCR was used to detect their expressions under rust spore induction.[Result]A total of 6 MYB and 2 bHLH family genes were identified,which were named CaMYB1-CaMYB6 and CabHLH1-CabHLH2.All the 6 CaMYBs genes contained a SANT conserved domain,and the 2 CabHLHs contained a HLH domain,respectively.All the 8 transcription factors were hydrophilic proteins with molecular weights of 49.25-155.66 ku,and theoretical isoelectric points of 4.75-9.90.Except for CaMYB5 which was located in the mitochondria,the rest were all located in the nucleus,and all contained promoter binding sites corresponding to pathogenic bacteria.RT-qPCR results revealed that there was no significant difference in the expressions of the 8 transcription factor genes at the early stage of rust spore induction;at 24 h after the induction,the relative expression levels of CaMYB3 and CaMYB5 genes were down-regulated,however,at 48-72 h after the induction,their expression levels were significantly higher in comparison to those at 0 h,especially the expres-sion level of CaMYB4 gene at 72 h,which was approximately 37.5-fold greater.The expression patterns unveiled the functions of CaMYBs and CabHLHs genes in the stress regulation of strain SYC23 in the middle to late stages of rust spore induction,and respon-ded in large quantities to fungal infection at 48 h after rust spore induction.[Conclusion]A total of 8 MYB and bHLH transcription factors which were related to mycoparasitism were successfully mined and identified in C.anthropophilum SYC23.