PhMYB37 Promotes Shoot Branching in Petunia

Petunia is one of the world’s most important flowers, and its branch development has long been a source of discussion. MYB transcription factors have been identified as important plant branching regulators. In this study, 113 R2R3-MYB genes were identified from the petunia genome. PhMYB genes, closely related to RAXs, were expressed at greater levels in axillary buds and roots. Decapitation and 6-BA did not regulate the expression of PhMYB37. PhMYB37 was localized in the nucleus. Heterologous overexpression of PhMYB37 promoted shoot branching in transgenic Arabidopsis while silencing of PhMYB37 inhibited shoot branching. These results suggest that PhMYB37 plays a critical and positive role in petunia shoot branching.