MaMYB4, a R2R3-MYB repressor transcription factors, negatively regulates the biosynthesis of anthocyanin in banana

Anthocyanins are spatiotemporally accumulated in certain tissues of particular species in banana plant and are major regulated by MYB transcription factors. However, this precise regulatory mechanism in banana remain to be determined. Here we reported the identification and characterization of MaMYB4, a R2R3-MYB repressor transcription factor, which possess EAR (ethylene-responsive element binding factor-associated amphiphilic repression) and TLLLFR motifs. MaMYB4 expression was induced by the accumulation of anthocyanins. Transgenic banana plants overexpressing MaMYB4 displayed a significant reduction in anthocyanin compared to wildtype. To investigate the effect of overexpression MaMYB4 on the entire transcriptome, RNA-seq profiling was performed with the leaves of wild-type and MaMYB4-overexpressors as materials.