THE STRUCTURE OF THE CYTOCHROME-OXIDASE SUBUNIT-II GENE AND ITS USE AS A NEW CHARACTER IN THE CONSTRUCTION OF THE PHYLOGENETIC TREE OF ANGIOSPERMAE

With the aim of correlating the structure of the intron present in the mitochondrial gene coding for subunit II of the cytochrome oxidase complex (coxII gene) with some aspects of Angiosperm evolution, we analysed the organization of the coxII gene from 30 plants belonging to 18 different orders. In all the monocotyledons tested, the gene contains an intron with a composite structure. Among dicot plants, 16 contain a split gene, 5 a continuous gene.The presence or the absence of intervening sequences in the genes of dicot plants does not seem to be a casual event, on the contrary it seems to be a feature of specific phylogenetic lines. Our results suggest that this approach, extended to a wider number of plant species, could make a contribution to the construction of the phylogenetic tree of Angiosperms.