Cytochromes P450 in the biosynthesis of glucosinolates and indole alkaloids

摘要

Characteristic of cruciferous plants is the synthesis of nitrogen-and sulfur-rich compounds,such as glucosinolates and indole alkaloids.The intact glucosinolates have limited biological activity,but give rise to an array of bio-active breakdown products when hydrolysed by endogenous beta-thioglucosidases(myrosinases)upon tissue disruption.Both glucosinolates and indole alkaloids constitute an important part of the defence of plants against herbivores and pathogens,with the difference that a basal level of glucosinolates is ever-present in the plant whereas indole alkaloids are true phytoalexins that are de novo synthesised upon pathogen attack.With the completion of the genome sequence of the model plant,Arabidopsis thaliana,which is a crucifer,many genes involved in the biosynthesis of glucosinolates and indole alkaloids have been identified and cytochromes P450 are key players in these pathways.In the present review,we will focus on the cytochromes P450 in the biosynthesis of both groups of compounds.Their functional roles and regulation will be discussed.