Abstract:In order to study the relationship between myelocytosis protein (MYC2) gene and insect resistance of Brassica napus, the cDNA sequence of BnMYC2 gene was cloned from Brassica napus restorer line R18, and the gene expression and insect resistance of transformation model plant Arabidopsis thaliana were analyzed. Bioinformatics analysis showed that BnMYC2 gene gDNA lack of intron structure. The cDNA complete open reading frame (ORF) was 1833 BP, encoding 610 amino acids. The putative gene was located on the C6 chromosome of Brassica napus and had the conserved domain HLH of bHLH transcription factor. The results of gene homology analysis showed that BnMYC2 had the closest genetic relationship with Arabidopsis, cabbage and radish, and the similarity of amino acids was more than 98%. Tissue specific expression analysis showed that BnMYC2 was expressed in all tested tissues including roots, stems, leaves, flowers, pods 27 days after flowering and pods 35 days after flowering, and the expression level was the highest in pods 27 days after flowering. The results of insect resistance experiment showed that the expression level of insect resistance gene VSP2 in overexpressing BnMYC2 Arabidopsis was significantly higher than that in the control. It is speculated that BnMYC2 gene in Brassica napus may participate in the response to insect stress as an important regulator.