Three duplication events and variable molecular evolution characteristics involved in multiple GGPS genes of six Solanaceae species

(E,E,E)-geranylgeranyl diphosphate (GGPP), an intermediate in the biosynthesis of terpenoids, which is synthesized through catalysation by geranylgeranyl diphosphate synthetases (GGPS) (Hefner et al. 1998). In this study, a total of 25 GGPS genes were identied in whole genome of six Solanaceae species. These genes were categorized into three subclades based on phylogenetic analysis, whose duplication was independent of duplication events of Arabidopsis. Three duplication events in evolution history of 25 Solanaceae GGPS (SolGGPS) genes were identied based on topology of phylogenetic tree. Molecular evolution analysis showed that branches emerging from different duplication events evolved under various evolution rates. One site of two branches after D3 duplication event evolved under positive selection pressure, which may be necessary for catalytic activity of target protein because of its specic location in the hole surrounded by three mainly conserved motifs based on three-dimensional analysis.