sentences:  Structural evidence suggests that these enzymes emerged by gain of function from ketoacyl synthase (KAS) III, an early stage enzyme of type II fatty acid biosynthesis.Although higher plant chalcone synthases have been extensively studied, little information is available on the enzymes from bryophytes (primitive plants).Cloning of CHS from the moss "Physcomitrella patens" revealed an important transition from the chalcone synthases present in microorganisms to those present in higher plants.