Adaptive evolution of the chrysanthemyl diphosphate synthase gene involved in irregular monoterpene metabolism

摘要: Chrysanthemyl diphosphate synthase (CDS) is a key enzyme in biosynthetic pathways producing pyrethrins and irregular monoterpenes. These compounds are confined to plants of the tribe Anthemideae Asteraceae, play an important role defending against herbivorous insects. It has been proposed that CDS genes arose from duplication farnesyl (FDS) gene have different function FDSs. However, time toward origin evolutionary force behind functional divergence still unknown. Two events were detected history FDS family second led CDS. occurred after Mutisieae other tribes Asteraceae but before birth tribe. After its origin, accumulated four mutations sites homologous substrate-binding catalysis FDS. Of these, two involved binding nucleophilic substrate isopentenyl Maximum likelihood analyses showed some under positive selection scattered throughout primary sequences, whereas three-dimensional structure model they clustered large central cavity. Positive associated with played major evolution