Monitors brassinosteroids (BR) responses and homeostasis, particularly in the root and hypocotyl in darkness (PubMed:22956280, PubMed:22544867). Promotes flavonoid biosynthesis (PubMed:22956280). Mostly expressed in roots (particularly in the root elongation zone), and, to a lower extent, in seedling, leaves (especially in hydathodes), siliques (e.g. in developing seeds) and flowers. Accumulates in response to brassinosteroids (BR) treatment (PubMed:22956280, PubMed:22544867). Induced by darkness in roots (PubMed:22544867). Belongs to the plant acyltransferase family.