Abstract
The first step of phenylpropanoid pathway in plants starts from phenylalanine. In plant cells, phenylalanine is converted to courmaric acid via cinnamic acid, then courmaric acid branches to various secondary metabolites. One more important branch point of this pathway is flavanone that is converted to flavone or isoflavone. In this study, we attempted to alter this pathway by using tyrosine ammonia-lyase (TAL), which directly converts tyrosine to coumaric acid instead of phenylalanine, and parsley flavone synthase (FNS). Expressions of the introduced genes were examined by RT-PCR or RNA gel-blot analysis, and the resulted transgenic plants were analyzed by LC-MS and HPLC to investigate profiles of their secondary metabolites. We observed accumulations of specific flavonoids that were dependent on the expression of transgene, TAL or FNS. We thus confirmed the in vivo functions of each trasgene that can alter the biosynthetic pathway of phenylpropanoids in Arabidopsis.
