title: Auxin-nonresponsive grape Aux/IAA19 is a positive regulator of plant growth.
abstract: We report the characterization of VvIAA19, an auxin/indole-3-acetic acid (Aux/IAA) protein, in grapevine (Vitis vinifera L.). VvIAA19 was expressed abundantly in berries. VvIAA19 transcription was rapidly increased at pre-anthesis and then decreased during fruit set. Before véraison, however, VvIAA19 gene expression was upregulated again and maximum expression was maintained until the end of ripening. Exogenous IAA did not induce VvIAA19 expression in grape leaves, suggesting that VvIAA19 might be auxin-nonresponsive. The overexpression of VvIAA19 in Arabidopsis thaliana had a notable effect on plant growth. Although no morphological changes were observed, transgenic Arabidopsis plants overexpressing VvIAA19 exhibited faster growth, including root elongation and floral transition, than the control plant, suggesting that the constitutive expression of VvIAA19 protein resulted in increased growth rates without any detectable harm. Taken together, we conclude that grape Aux/IAA19 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: Minako
authors.initials: M
authors.lastname: Kohno
authors.forename: Haruka
authors.initials: H
authors.lastname: Takato
authors.forename: Haruka
authors.initials: H
authors.lastname: Horiuchi
authors.forename: Keiko
authors.initials: K
authors.lastname: Fujita
authors.forename: Shunji
authors.initials: S
authors.lastname: Suzuki
mesh_terms: D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D016000:Cluster Analysis; D017931:DNA Primers / Q000235:genetics; D005638:Fruit / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology*; D007210:Indoleacetic Acids / Q000378:metabolism; D010641:Phenotype; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D027843:Vitis / Q000235:genetics / Q000254:growth & development*
chemical_list: D029681:Arabidopsis Proteins; D017931:DNA Primers; C483308:IAA19 protein, Arabidopsis; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010940:Plant Proteins; C030737:indoleacetic acid