Expression of Parsley Flavone Synthase I Establishes the Flavone Biosynthetic Pathway in Arabidopsis thaliana

摘要

Arabidopsis thaliana lacks the flavone biosynthetic pathway,probably because of a lack or low activity of a flavone synthase.To establish this biosynthetic pathway in Arabidopsis,we subjected this model plant to transformation with the parsley gene for flavone synthase type I(FNS-I).Transgenic seedlings expressing FNS-I were cultured in liquid medium with or without naringenin,and plant extracts were then analyzed by high-performance liquid chromatography.In contrast to wild-type seedlings,the transgenic seedlings accumulated substantial amounts of apigenin,which is produced from naringenin by FNS-I,and the apigenin level correlated with the abundance of FNS-I mRNA in three different transgenic lines.These results indicate that the FNS-I transgene produces a functional enzyme that catalyzes the conversion of naringenin to apigenin in Arabidopsis.These FNS-I transgenic lines should prove useful in investigating the in vivo functions of enzymes that mediate the synthesis of the wide variety of flavones found in other plants.