GENETIC COMPLEMENTATION OF A FLORAL HOMEOTIC MUTATION, APETALA3, WITH AN ARABIDOPSIS-THALIANA GENE HOMOLOGOUS TO DEFICIENS OF ANTIRRHINUM-MAJUS

Among the homeotic mutants with altered floral organs, two mutants of Arabidopsis thaliana, apetala3 and pistillata, and two mutants of Antirrhinum majus, deficiens and globosa, have a homeotic conversion of the floral organs in whorl 2 and 3, namely petals to sepals and stamens to carpels. We have isolated a homologue of the DEFICIENS gene from A. thaliana wild type and shown complete complementation of apetala3 mutation by introducing the isolated gene using Agrobacterium-mediated transformation. These results show that the APETALA3 is a homologue of DEFICIENS structurally and functionally. The 5'-upstream region of APETALA3 contains three SRE-like sequence, where MADS box-containing proteins are assumed to bind and regulate expression in tissue- and stage-specific manner.