title: Perturbation of auxin homeostasis by overexpression of wild-type IAA15 results in impaired stem cell differentiation and gravitropism in roots.
abstract: Aux/IAAs interact with auxin response factors (ARFs) to repress their transcriptional activity in the auxin signaling pathway. Previous studies have focused on gain-of-function mutations of domain II and little is known about whether the expression level of wild-type Aux/IAAs can modulate auxin homeostasis. Here we examined the perturbation of auxin homeostasis by ectopic expression of wild-type IAA15. Root gravitropism and stem cell differentiation were also analyzed. The transgenic lines were less sensitive to exogenous auxin and exhibited low-auxin phenotypes including failures in gravity response and defects in stem cell differentiation. Overexpression lines also showed an increase in auxin concentration and reduced polar auxin transport. These results demonstrate that an alteration in the expression of wild-type IAA15 can disrupt auxin homeostasis.
authors.affiliation: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, Hubei, China.
authors.forename: Da-Wei
authors.initials: DW
authors.lastname: Yan
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Yuan
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Hong
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
authors.forename: Ying-Tang
authors.initials: YT
authors.lastname: Lu
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D018522:Gravitropism; D006706:Homeostasis; D018546:Hypocotyl / Q000235:genetics; D007210:Indoleacetic Acids / Q000378:metabolism*; D018519:Meristem / Q000378:metabolism; D010641:Phenotype; D010802:Phylogeny; D018517:Plant Roots / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology*
chemical_list: D029681:Arabidopsis Proteins; C584643:IAA15 protein, Arabidopsis; D007210:Indoleacetic Acids