Phenylpropanoid biosynthesis genes

Expression and manipulation of genes involved in phenylpropanoid biosynthesis... 

DIXON, R.A., LAMB, C.J., MASOUD, S., SEWALT, V.J., PAIVA, N.L., Metabolic engineering Prospects for crop improvement through the genetic manipulation of phenylpropanoid biosynthesis and defense responses—a review, Gene, 1996,179, 61-71. 

First, Ro and Douglas constructed the initial steps of the plant phenylpropanoid pathway by connecting two enzymes, PAL and C4H, with a cytochrome P450 reductase (CPR) from a plant source in S. cerevisiae [31]. This heterologous transfer of plant phenylpropanoid pathway genes into yeast became the platform for the biosynthesis of various flavonoids and related compounds in microbial... 

One aspect shared with several other genes of the phenylpropanoid pathway is the transient induction after environmental challenge. This has also been demonstrated for chalcone synthase (Ryder et al., 1984) and chalcone isomerase (Cramer et al., 1985 Mehdy Lamb, 1987), enzymes involved in phytoalexin production, and for cinnamyl alcohol dehydrogenase (CAD) an enzyme of lignin biosynthesis, in response to elicitor treatment of bean tissue culture cells (Grand et al., 1987). 

Type 2 MTs, also currently understood to function exclusively as OMTs, are found in all lignin-producing plants. This family is specific for coenzyme A derivatized phenylpropanoid compounds and appears to be less diverse in sequence and gene number than the type 1 family of MTs (Fig. 2.3). Based on database searches, type 2 OMTs consist of caffeoyl and feruloyl coenzyme-A specific OMTs (CCoAOMTs). The most closely related enzymes to plant CCoAOMTs are the mammalian small molecule methyltransferases, including catechol OMT and bacterial MTs involved in macrolide biosynthesis. 

Degradation products of LOOHs are able to initiate the production of the ethylene, kinases and G-proteins required to induce an oxidative burst. These events are apparently followed by activation of the genes which encode the generation of jasmonic acid and of salicylic acid. These are in turn able to induce the production of enzymes of the phenylpropanoid pathway [149,150], and enzymes which initiate the biosynthesis of terpenes (e.g. 3-hydroxy-3-methylglutaryl coenzyme A reductase [145,151-153]) and lignins. 

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