Genome-Wide Analysis of the MYB-Related Transcription Factor Family in Pepper and Functional Studies of Involvement in Capsaicin Biosynthesis.

Chili pepper is an important economic vegetable worldwide. family gene members play an important role in the metabolic processes in plant growth and development. In this study, 103 pepper -related members were identified and grouped into nine subfamilies according to phylogenetic relationships. Additionally, a total of 80, 20, and 37 collinear gene pairs were identified between pepper and tomato, pepper and , and tomato and , respectively. We performed promoter -element analysis and showed that -related members may be involved in multiple biological processes such as growth and development, secondary metabolism, and circadian rhythm regulation. Expression pattern analysis indicated that is significantly more enriched in fruit placenta, suggesting that this gene may be involved in capsaicin biosynthesis. Through VIGS, we confirmed that is critical for the biosynthesis of capsaicin in placenta. Our subcellular localization studies revealed that CaMYB37 localized in the nucleus. On the basis of yeast one-hybrid and dual-luciferase reporter assays, we found that CaMYB37 directly binds to the promoter of capsaicin biosynthesis gene and activates its transcription, thereby regulating capsaicin biosynthesis. In summary, we systematically identified members of the -related family, predicted their possible biological functions, and revealed that is critical for the transcriptional regulation of capsaicin biosynthesis. This work provides a foundation for further studies of the CaMYB-related family in pepper growth and development.