title: Transcriptional changes of gibberellin oxidase genes in grapevines with or without gibberellin application during inflorescence development.
abstract: The concept that gibberellin (GA) application on seeded grapevines induces seedlessness has been known for decades in viticulture. GA was applied to inflorescence clusters of seeded diploid grapevine cultivar 'Tamnara' (Vitis spp.) at 14 days before full bloom (DBF). Morphological and molecular effects of GA application were examined on the induction of parthenocarpic fruit development. With GA application, ovaries were enlarged and pollen tube growth was completely inhibited. Vitis GA oxidase enzymes, key determinants for GA level, were characterized through phylogenetic analysis with Arabidopsis GA oxidase enzymes. Five VvGA 20-oxidase (VvGA20ox), three VvGA 3-oxidase (VvGA3ox), and nine VvGA 2-oxidase (VvGA2ox) family proteins, and one VvGA methyltransferase (VvGAMT) and one Vitis cytochrome P450 714A1 proteins were identified, and their expression patterns were analyzed during inflorescence development from 14 DBF to 5 days after full bloom (DAF). VvGA2ox1, VvGA20ox3, and VvGA3ox2 were the most abundantly expressed genes in each gene family at 7, 5, and 2 DBF, respectively. Following GA application at 14 DBF inducing seedlessness, GA catabolic genes such as VvGAMT2, VvGA2ox3, and VvGA2ox4 were up-regulated at 12 DBF, full bloom, and 5 DAF, respectively. Conversely, most GA biosynthetic genes, VvGA20oxs and VvGA3oxs, were down-regulated at near full bloom, and the timing of their peak expression was changed. These results suggest that GA application at pre-bloom changes the GA biosynthesis into GA catabolic pathway at near full bloom by altering the transcription level and timing of GA oxidase genes during grapevine inflorescence development.
authors.affiliation: Fruit Research Division, National Institute of Horticultural and Herbal Science, Rural Development Administration, Suwon, 440-706, Republic of Korea.
authors.forename: Chan Jin
authors.initials: CJ
authors.lastname: Jung
authors.forename: Youn Young
authors.initials: YY
authors.lastname: Hur
authors.forename: Sung-Min
authors.initials: SM
authors.lastname: Jung
authors.forename: Jung-Ho
authors.initials: JH
authors.lastname: Noh
authors.forename: Gyung-Ran
authors.initials: GR
authors.lastname: Do
authors.forename: Seo-June
authors.initials: SJ
authors.lastname: Park
authors.forename: Jong-Chul
authors.initials: JC
authors.lastname: Nam
authors.forename: Kyo-Sun
authors.initials: KS
authors.lastname: Park
authors.forename: Hae-Sung
authors.initials: HS
authors.lastname: Hwang
authors.forename: Doil
authors.initials: D
authors.lastname: Choi
authors.forename: Hee Jae
authors.initials: HJ
authors.lastname: Lee
mesh_terms: D018076:DNA, Complementary / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000378:metabolism* / Q000494:pharmacology; D056626:Inflorescence / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D018749:RNA, Plant / Q000235:genetics; D012639:Seeds / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D027843:Vitis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development
chemical_list: D018076:DNA, Complementary; D005875:Gibberellins; D010940:Plant Proteins; D018749:RNA, Plant; D010088:Oxidoreductases