MYB Transcription Repressors Regulate Plant Secondary Metabolism

MYB transcription factors (TFs) belong to one of the largest and important gene families, which regulate development under changing environmental conditions, primary and secondary metabolism, and plant response to stresses (biotic and abiotic stresses). MYB repressors have a conserved N-terminal domain like other MYB TFs, but the C-terminal domain makes them structurally and functionally different from the rest. MYB repressors usually possess some repressive motifs, such as EAR (ethylene-responsive element binding factor-associated amphiphilic repression motif), SID (Sensitive to ABA and Drought 2 protein interact motif), and TLLLFR motifs, which contribute to their repression function through a variety of complex regulatory mechanisms. In this review, we summarize recent developments in research of MYB repressors and suggest directions to future research.