Isoflavones are secondary metabolites found mostly in legumes.The pathway of isoflavone biosynthesis is a branch of phenylpropanoid pathway.The key enzymes of isofavone biosynthesis are phenylala-nine ammonia lyase(PAL),chalcone synthase(CHS),chalcone isomerase(CHI),isoflavone synthase(IFS).The pathway of the biosynthesis is regulated transcriptionally and posttranscriptionally.Various ways could induce the biosynthesis transcriptionally such as metabolic engineering,light,circadian regulation and jasmonoid...