Genetic characterization of mutants resistant to the antiauxin p-chlorophenoxyisobutyric acid reveals that AAR3, a gene encoding a DCN1-like protein, regulates responses to the synthetic auxin 2,4-dichlorophenoxyacetic acid in Arabidopsis roots.
To isolate novel auxin-responsive mutants in Arabidopsis (Arabidopsis thaliana), we screened mutants for root growth resistance to a putative antiauxin, p-chlorophenoxyisobutyric acid (PCIB), which inhibits auxin action by interfering the upstream auxin-signaling events. Eleven PCIB-resistant mutants were obtained. Genetic mapping indicates that the mutations are located in at least five independent loci, including two known auxin-related loci, TRANSPORT INHIBITOR RESPONSE1 and Arabidopsis CULLIN1. antiauxin-resistant mutants (aars) aar3-1, aar4, and aar5 were also resistant to 2,4-dichlorophenoxyacetic acid as shown by a root growth assay. Positional cloning of aar3-1 revealed that the AAR3 gene encodes a protein with a domain of unknown function (DUF298), which has not previously been implicated in auxin signaling. The protein has a putative nuclear localization signal and shares homology with the DEFECTIVE IN CULLIN NEDDYLATION-1 protein through the DUF298 domain. The results also indicate that PCIB can facilitate the identification of factors involved in auxin or auxin-related signaling.
Biswas
Kamal Kanti
KK
Radiation-Applied Biology Division, Japan Atomic Energy Agency, Takasaki 370-1292, Japan.
Ooura
Chiharu
C
Higuchi
Kanako
K
Miyazaki
Yuji
Y
Van Nguyen
Vinh
V
Rahman
Abidur
A
Uchimiya
Hirofumi
H
Kiyosue
Tomohiro
T
Koshiba
Tomokazu
T
Tanaka
Atsushi
A
Narumi
Issay
I
Oono
Yutaka
Y
D015084:2,4-Dichlorophenoxyacetic Acid / Q000494:pharmacology*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics*; D018797:Cell Cycle Proteins; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D002995:Clofibric Acid / Q000494:pharmacology*; D003001:Cloning, Molecular; D044842:Cullin Proteins; D044783:F-Box Proteins; D053209:Herbicide Resistance; D006540:Herbicides / Q000494:pharmacology; D008969:Molecular Sequence Data; D009154:Mutation; D018517:Plant Roots / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D011956:Receptors, Cell Surface
C525657:AAR3 protein, Arabidopsis; D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; C100318:Cullin 1; D044842:Cullin Proteins; D044783:F-Box Proteins; D006540:Herbicides; D011956:Receptors, Cell Surface; C501405:TIR1 protein, Arabidopsis; D015084:2,4-Dichlorophenoxyacetic Acid; D002995:Clofibric Acid