title: Transactivation of anthocyanin biosynthetic genes following transfer of B regulatory genes into maize tissues.
abstract: The C1, B and R genes regulating the maize anthocyanin biosynthetic pathway encode tissue-specific regulatory proteins with similarities to transcriptional activators. The C1 and R regulatory genes are usually responsible for pigmentation of seed tissues, and the B-Peru allele of B, but not the B-I allele, can substitute for R function in the seed. In this study, members of the B family of regulatory genes were delivered to intact maize tissues by high velocity microprojectiles. In colorless r aleurones or embryos, the introduction of the B-Peru genomic clone or the expressed cDNAs of B-Peru or B-I resulted in anthocyanin-producing cells. Luciferase produced from the Bronze1 anthocyanin structural gene promoter was induced 100-fold when co-introduced with the expressed B-Peru or B-I cDNAs. This quantitative transactivation assay demonstrates that the proteins encoded by these two B alleles are equally able to transactivate the Bronze1 promoter. Analogous results were obtained using embryogenic callus cells. These observations suggest that one major contribution towards tissue-specific anthocyanin synthesis controlled by the various alleles of the B and R genes is the differential expression of functionally similar proteins.
authors.affiliation: Plant Gene Expression Center, USDA/UC Berkeley, Albany, CA 94710.
authors.forename: S A
authors.initials: SA
authors.lastname: Goff
authors.forename: T M
authors.initials: TM
authors.lastname: Klein
authors.forename: B A
authors.initials: BA
authors.lastname: Roth
authors.forename: M E
authors.initials: ME
authors.lastname: Fromm
authors.forename: K C
authors.initials: KC
authors.lastname: Cone
authors.forename: J P
authors.initials: JP
authors.lastname: Radicella
authors.forename: V L
authors.initials: VL
authors.lastname: Chandler
mesh_terms: D000483:Alleles; D000872:Anthocyanins / Q000378:metabolism*; D001483:Base Sequence; D002460:Cell Line; D005786:Gene Expression Regulation; D005809:Genes, Regulator; D005813:Genes, Synthetic; D005816:Genetic Complementation Test; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D009029:Mosaic Viruses / Q000235:genetics; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics*; D010957:Plasmids; D011401:Promoter Regions, Genetic; D015534:Trans-Activators / Q000235:genetics; D014162:Transfection; D003313:Zea mays / Q000235:genetics*
chemical_list: D000872:Anthocyanins; D010940:Plant Proteins; D015534:Trans-Activators