, a gene encoding a DCN1-like protein, regulates responses to the synthetic auxin 2,4-dichlorophenoxyacetic acid in arabidopsis roots

Ono, Yutaka; Biswas, K. K.*; Miyazaki, Yuji*; Kiyosue, Tomohiro*; Narumi, Issei

We have screened Arabidopsis mutants for root growth resistance to a putative antiauxin, -chlorophenoxyisobutyric acid (PCIB). We have successfully isolated at least three novel antiauxin-resistant mutants (). The , mutant was also resistant to 2,4-D as shown by a root growth assay. The gene encodes a protein with a domain of unknown function (DUF298). The protein has a putative nuclear localization signal and its nuclear localization was confirmed by a protoplast transient assay. The protein shares homology with the DEFECTIVE IN CULLIN NEDDYLATION-1 protein through the DUF298 domain. However, no significant difference in the auxin responsive markers, or , was observed between the wild type and , suggesting that the gene regulates 2,4-D sensitivity through a previously uncharacterized mechanism.