Interaction among C, R and Vp in the Control of the Bz Glucosyltransferase during Endosperm Development in Maize.

THE ENZYME UPD GLUCOSE: flavonoid 3-O-glucosyltransferase (UFGT), involved in anthocyanin biosynthesis, is controlled by at least four genes (Bz, C, R and Vp) in the maize endosperm. Bz is the structural gene for the enzyme. Early in endosperm development, the enzyme is present in an uninduced low level that is independent of C, R and Vp, and dependent solely on Bz. Beginning at about the fourth week of development, C, R and Vp interact with each other to induce high levels of UFGT. The enzyme accumulates thereafter in normal endosperms, reaching its highest level at maturity. The nature of the developmental signal (s) controlled by C, R and Vp is discussed.