Mutations in the AXR3 gene of Arabidopsis result in altered auxin response including ectopic expression from the SAUR-AC1 promoter.
A new auxin response gene in Arabidopsis called AXR3 has been identified. This gene is defined by two semi-dominant mutations which affect many auxin-regulated developmental processes. Auxin has been shown to maintain apical dominance, inhibit root elongation, stimulate adventitious rooting, mediate root gravitropism, and stimulate transcription from the SAUR-AC1 promoter. Mutant axr3 plants show enhanced apical dominance, reduced root elongation, increased adventitious rooting, no root gravitropism, and ectopic expression from the SAUR-AC1 promoter. These phenotypes suggest an increased auxin response in the mutants. In support of this hypothesis, many of the phenotypes are partially restored to wild-type by exogenous cytokinin, a treatment that could restore a more wild-type auxin to cytokinin ratio.
Leyser
H M
HM
Department of Biology, Indiana University, Bloomington 47405, USA.
Pickett
F B
FB
Dharmasiri
S
S
Estelle
M
M
D015084:2,4-Dichlorophenoxyacetic Acid / Q000494:pharmacology; D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000596:Amino Acids / Q000494:pharmacology; D000598:Amino Acids, Cyclic; D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins; D001593:Benzyl Compounds; D003583:Cytokinins / Q000494:pharmacology; D015870:Gene Expression; D017343:Genes, Plant; D007210:Indoleacetic Acids / Q000494:pharmacology*; D007701:Kinetin; D009154:Mutation; D009280:Naphthaleneacetic Acids / Q000494:pharmacology; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011687:Purines; D014158:Transcription, Genetic
D000596:Amino Acids; D000598:Amino Acids, Cyclic; D029681:Arabidopsis Proteins; D001593:Benzyl Compounds; D003583:Cytokinins; D007210:Indoleacetic Acids; D009280:Naphthaleneacetic Acids; D010940:Plant Proteins; D011687:Purines; C086789:SAUR-AC1 protein, Arabidopsis; D015084:2,4-Dichlorophenoxyacetic Acid; C034182:1-naphthaleneacetic acid; C023863:1-aminocyclopropane-1-carboxylic acid; C030737:indoleacetic acid; D000225:Adenine; C480551:benzylaminopurine; D007701:Kinetin