Abstract
Previous studies using rice tillering dwarf mutants suggested that DWARF14 (D14), encoding a member of the Alpha/Beta-hydrolase superfamily, regulates shoot branching in a step downstream of strigolactone biosynthesis. To explore whether D14-related gene(s) acts in the strigolactone-dependent pathway in other plant species, we have been studying the physiological roles of D14 homologs in Arabidopsis through reverse genetics. We found that Arabidopsis mutants defective in a likely D14 ortholog are phenotypically similar to the strigolactone-deficient max1, max3 and max4 mutants, including increased axillary bud outgrowth and reduced petiole lengths in rosette leaves, but are insensitive to strigolactone. In contrast to d14, max2, another strigolactone-insensitive mutant defective in an F-box protein, shows extra phenotypes that are not observed in the strigolactone-deficient max mutants. Our recent results suggest that another D14-related gene might be involved in the MAX1/MAX3/MAX4-independent max2 phenotypes in Arabidopsis.
