FLORAL EXPRESSION OF A GENE ENCODING AN E2-RELATED UBIQUITIN-CONJUGATING PROTEIN FROM ARABIDOPSIS-THALIANA

An Arabidopsis thaliana gene (UBC6) encoding a homologue to ubiquitin- conjugating enzymes has been isolated which is capable of encoding a p rotein of 183 amino acids of ca. 21 kDa. Northern analysis indicates t hat the gene is expressed in flowers, seeds and, to a somewhat lesser extent, in 10-day seedlings but not in mature leaves, callus and pre-f lowering plants. This pattern of expression is confirmed using transge nic Arabidopsis plants containing a UBC6 promoter-GUS gene fusion cons truct. These plants display GUS activity in mature anthers prior to de hiscence, in developing embryos, sepals and the style after pollinatio n.