title: Auxin-responsive grape Aux/IAA9 regulates transgenic Arabidopsis plant growth.
abstract: We report the characterization of VvIAA9, an auxin/indole-3-acetic acid (Aux/IAA) protein, in grapevine (Vitis vinifera L.). VvIAA9 was expressed abundantly in leaves and berries. VvIAA9 transcription was drastically upregulated from anthesis to onset of ripening (termed véraison), in which berry diameter rapidly increased. Treatment with exogenous IAA induced VvIAA9 expression in grape leaves, suggesting that VvIAA9 is an auxin-responsive Aux/IAA protein. The overexpression of VvIAA9 in Arabidopsis thaliana promoted plant growth, including rapid floral transition. However, no morphological differences were observed between the control plant and the VvIAA9-overexpressing plant. The overexpression of VvIAA9 in Arabidopsis plants rendered the plants hyposensitive to exogenous IAA. The exogenous IAA treatment did not induce VvIAA9-overexpressing Arabidopsis plant growth and expression of IAA-responsive HAT2. Taken together, we conclude that grape Aux/IAA9 protein is likely to play a crucial role as a plant growth regulator.
authors.affiliation: Laboratory of Fruit Genetics Engineering, The Institute of Enology and Viticulture, University of Yamanashi, Kofu, Yamanashi 400-0005, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Fujita
authors.forename: Haruka
authors.initials: H
authors.lastname: Horiuchi
authors.forename: Haruka
authors.initials: H
authors.lastname: Takato
authors.forename: Minako
authors.initials: M
authors.lastname: Kohno
authors.forename: Shunji
authors.initials: S
authors.lastname: Suzuki
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000096:biosynthesis; D035264:Flowers / Q000187:drug effects / Q000254:growth & development; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018398:Homeodomain Proteins / Q000096:biosynthesis; D007210:Indoleacetic Acids / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010937:Plant Growth Regulators / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D027843:Vitis / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C473621:HAT2 protein, Arabidopsis; D018398:Homeodomain Proteins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010940:Plant Proteins; C030737:indoleacetic acid