ORCA3, a jasmonate-responsive transcriptional regulator of plant primary and secondary metabolism

Biosynthesis of many classes of secondary metabolites in plants is induced by the stress hormone jasmonate. The gene for ORCA3, a jasmonate-responsive APETALA2 (AP2)-domain transcription factor from Catharanthus roseus, was i solated by transferred DNA activation tagging. Orca3 overexpression resulte d in enhanced expression of several metabolite biosynthetic genes and, cons equently, in increased accumulation of terpenoid indole alkaloids, Regulati on of metabolite biosynthetic genes by jasmonate-responsive AP2-domain tran scription factors may link plant stress responses to changes in metabolism.