title: Activation tagging in tomato identifies a transcriptional regulator of anthocyanin biosynthesis, modification, and transport.
abstract: We have developed a high-throughput T-DNA insertional mutagenesis program in tomato using activation tagging to identify genes that regulate metabolic pathways. One of the activation-tagged insertion lines (ant1) showed intense purple pigmentation from the very early stage of shoot formation in culture, reflecting activation of the biosynthetic pathway leading to anthocyanin accumulation. The purple coloration resulted from the overexpression of a gene that encodes a MYB transcription factor. Vegetative tissues of ant1 plants displayed intense purple color, and the fruit showed purple spotting on the epidermis and pericarp. The gene-to-trait relationship of ant1 was confirmed by the overexpression of ANT1 in transgenic tomato and in tobacco under the control of a constitutive promoter. Suppression subtractive hybridization and RNA hybridization analysis of the purple tomato plants indicated that the overexpression of ANT1 caused the upregulation of genes that encode proteins in both the early and later steps of anthocyanidin biosynthesis as well as genes involved in the glycosylation and transport of anthocyanins into the vacuole.
authors.affiliation: Exelixis Plant Sciences, Inc., Portland, OR 97224-7744, USA. hmathews@exelixis.com
authors.forename: Helena
authors.initials: H
authors.lastname: Mathews
authors.forename: Stephanie K
authors.initials: SK
authors.lastname: Clendennen
authors.forename: Colby G
authors.initials: CG
authors.lastname: Caldwell
authors.forename: Xing Liang
authors.initials: XL
authors.lastname: Liu
authors.forename: Karin
authors.initials: K
authors.lastname: Connors
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Matheis
authors.forename: Debra K
authors.initials: DK
authors.lastname: Schuster
authors.forename: D J
authors.initials: DJ
authors.lastname: Menasco
authors.forename: Wendy
authors.initials: W
authors.lastname: Wagoner
authors.forename: Jonathan
authors.initials: J
authors.lastname: Lightner
authors.forename: D Ry
authors.initials: DR
authors.lastname: Wagner
mesh_terms: D000595:Amino Acid Sequence; D000872:Anthocyanins / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D017343:Genes, Plant; D018551:Solanum lycopersicum / Q000033:anatomy & histology / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010641:Phenotype; D010858:Pigmentation / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics; D030821:Plants, Genetically Modified; D017386:Sequence Homology, Amino Acid; D015533:Transcriptional Activation
chemical_list: D000872:Anthocyanins; D004269:DNA, Bacterial; D018744:DNA, Plant; D010940:Plant Proteins; C036483:T-DNA