title: yucca6, a dominant mutation in Arabidopsis, affects auxin accumulation and auxin-related phenotypes.
abstract: Auxin plays critical roles in many aspects of plant growth and development. Although a number of auxin biosynthetic pathways have been identified, their overlapping nature has prevented a clear elucidation of auxin biosynthesis. Recently, Arabidopsis (Arabidopsis thaliana) mutants with supernormal auxin phenotypes have been reported. These mutants exhibit hyperactivation of genes belonging to the YUCCA family, encoding putative flavin monooxygenase enzymes that result in increased endogenous auxin levels. Here, we report the discovery of fertile dominant Arabidopsis hypertall1-1D and hypertall1-2D (yucca6-1D, -2D) mutants that exhibit typical auxin overproduction phenotypic alterations, such as epinastic cotyledons, increased apical dominance, and curled leaves. However, unlike other auxin overproduction mutants, yucca6 plants do not display short or hairy root phenotypes and lack morphological changes under dark conditions. In addition, yucca6-1D and yucca6-2D have extremely tall (>1 m) inflorescences with extreme apical dominance and twisted cauline leaves. Microarray analyses revealed that expression of several indole-3-acetic acid-inducible genes, including Aux/IAA, SMALL AUXIN-UP RNA, and GH3, is severalfold higher in yucca6 mutants than in the wild type. Tryptophan (Trp) analog feeding experiments and catalytic activity assays with recombinant YUCCA6 indicate that YUCCA6 is involved in a Trp-dependent auxin biosynthesis pathway. YUCCA6:GREEN FLUORESCENT PROTEIN fusion protein indicates YUCCA6 protein exhibits a nonplastidial subcellular localization in an unidentified intracellular compartment. Taken together, our results identify YUCCA6 as a functional member of the YUCCA family with unique roles in growth and development.
authors: Center for Plant Environmental Stress Physiology , Purdue University, West Lafayette, Indiana 47906-2010, USA.
authors: Jeong Im
authors: JI
authors: Kim
authors: Altanbadralt
authors: A
authors: Sharkhuu
authors: Jing Bo
authors: JB
authors: Jin
authors: Pinghua
authors: P
authors: Li
authors: Jae Cheol
authors: JC
authors: Jeong
authors: Dongwon
authors: D
authors: Baek
authors: Sang Yeol
authors: SY
authors: Lee
authors: Joshua J
authors: JJ
authors: Blakeslee
authors: Angus S
authors: AS
authors: Murphy
authors: Hans J
authors: HJ
authors: Bohnert
authors: Paul M
authors: PM
authors: Hasegawa
authors: Dae-Jin
authors: DJ
authors: Yun
authors: Ray A
authors: RA
authors: Bressan
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D035264:Flowers / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005799:Genes, Dominant / Q000235:genetics; D007210:Indoleacetic Acids / Q000378:metabolism*; D005810:Multigene Family; D016254:Mutagenesis, Insertional; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D018744:DNA, Plant; D007210:Indoleacetic Acids; C036483:T-DNA; C030737:indoleacetic acid