Isolation and Characterization of a novel Arabidopsis mutant cof1 that defects epidermal cuticular waxes.

Abstract

We have found two new mutants, cof1-1 and cof1-2 (cuticular defect and organ fusion), in transposon-tagged lines of Arabidopsis, showing same phenotypes of wilty, adhesion in rosette leaves and sterile. By Toluidine-blue test, SEM and TEM, these mutants were detected to have cuticular defects in leaves and stems. These two mutants have a transposon-insertion in same gene, which is the AtWBC11 classified to ABC transporter AtWBC subfamily. AtWBC11 is a highly homologous gene of CER5/AtWBC12, which is reported to be related for cuticular lipid export. Gas-chromatography analysis reveled that the amount of alkanes, the main compound of cuticular wax, extracted from leaves and stems of cof1-1 were remarkably reduced. AtWBC11 protein fused with CFP protein was localized to the plasma membrane of plant cells. These results suggest that COF1/AtWBC11 has an important role in wax transport to construct the cuticle layers for developmental formation.