Genome-Wide Analysis of MYB Transcription Factor Gene Superfamily Reveals BjPHL2a Involved in Modulating the Expression of BjCHI1 in Brassica juncea

is an economically important vegetable and oilseed crop. The MYB transcription factor superfamily is one of the largest transcription factor families in plants, and plays crucial roles in regulating the expression of key genes involved in a variety of physiological processes. However, a systematic analysis of the MYB transcription factor genes in has not been performed. In this study, a total of 502 BjMYB superfamily transcription factor genes were identified, including 23 1R-MYBs, 388 R2R3-MYBs, 16 3R-MYBs, 4 4R-MYBs, 7 atypical MYBs, and 64 MYB-CCs, which is approximately 2.4-fold larger than that of AtMYBs. Phylogenetic relationship analysis revealed that the MYB-CC subfamily consists of 64 genes. The expression pattern of members of PHL2 subclade homologous genes in after infection were determined, and was isolated from a yeast one-hybrid screen with the promoter of as bait. was found to localize mainly in the nucleus of plant cells. An EMSA assay confirmed that binds to the Wbl-4 element of . Transiently expressed activates expression of the GUS reporter system driven by a mini-promoter in tobacco ( ) leaves. Taken together, our data provide a comprehensive evaluation of and show that , one of the members of BjMYB-CCs, functions as a transcription activator by interacting with the Wbl-4 element in the promoter of for targeted gene-inducible expression.