Computational and evolutionary insights into anthocyanin biosynthesis genes between Solanaceae and Poaceae

Six common anthocyanin pathway genes viz. Chalcone synthase (CHS), Chalcone isomerase (CHI), Flavanone 3-hydroxylase (F3H), Dihydrofolate reductase (DFR), Anthocyanindin synthase (ANS) and UDPG-flavonoid 3-glucosyl transferase (UF3GT) were analyzed by performing comparative analysis between different species of solanaceae and poacea families. Sequence conservation between different species of these two families was highest in CHS and lowest in CHI. The number of polymorphic sites between different species of these two families was highest in ANS and lowest in F3H. McDonald–Kreitman analysis showed that non-synonymous changes between different species of these two families were higher for downstream enzymes: UF3GT, DFR and ANS than upstream enzymes: CHS, CHI and F3H. It was also observed that nucleotide diversity between these two families was highest in CHI but lowest in F3H. From the evolutionary analysis it was concluded that that CHI might have undergone ancient duplication and subsequent divergence during evolution and upstream enzymes CHS and CHI evolves very slowly than downstream enzymes DFR, ANS and UF3GT not because of their mutation rate but because of the selective constraint between different species of solanaceae and poaceae.