Phenylpropanoids and

The use of nitrogen fertilization results in higher content of N-containing compounds, including free amino acids, and also increases in terpene content in wood plants, whilst starch, total carbohydrates, phenylpropanoids and total carbon-based phytochemicals decreased (Koricheva et al., 1998). Higher levels of nitrogen favoured its uptake and increased the nitrate content of the crop, which is critical for salad vegetables and baby foods. 

In addition, it has been discovered that there are naturally occurring enzymes that facilitate Diels-Alder type reactions within certain metabolic pathways and that enzymes are also instrumental in forming polyketides, isoprenoids, phenylpropanoids, and alkaloids (de Araujo et al., 2006). Agresti et al. (2005) identified ribozymes from RNA oligo libraries that catalyzed multiple-turnover Diels-Alder cycloaddition reactions. 

WINKEL-SHIRLEY, B., Evidence for enzyme complexes in the phenylpropanoid and flavonoid pathways, Physiol. Plant., 1999,107, 142-149. 

Tan JW, Bednarek P, Liu HK, Schneider B, Svatos A, Hahlbrock K (2004) Universally occurring phenylpropanoid and species-specific indolic metabolites in infected and uninfected Arabidopsis thaliana roots and leaves. Phytochemistry 65 691-699... 

Table 6.1 Citrus phenylpropanoid and core flavonoid biosynthetic enzymes...

Hall R, Holden M, Yeoman M (1987) The accumulation of phenylpropanoid and capsaicinoid compounds in cell cultures and whole fruit of the chili pepper, Capsicum frutescens MiU. Plant Cell Tissue Organ Cult 8 163-176... 

Suberin is a composite of polymeric phenylpropanoids and ester-linked long chain fatty acids and alcohols and consists of a hydrophobic layer attached to the cell walls of roots, bark and the vascular system (8,10). The phenylpropanoid portion of suberin purportedly has a lignin-like structure to which both aliphatic domains and hydroxycinnamic acids are esterified. 

FIGURE 3.2 General phenylpropanoid and flavonoid bios5mthetic pathways. The B-ring hydroxylation steps are not shown. For formation of anthocyanins from leucoanthocyanidins two routes are represented a simplified scheme via the anthocyanidin (pelargonidin) and the likely in vivo route via the pseudobase. Enzyme abbreviations are defined in the text and in Table 3.1. 

MYB, PI or P2 Zea mays cell lines 3-Deoxyflavonoids, C-glycosylflavones, other phenylpropanoids and fluorescent compounds increased 140, 317... 

Petersen, M., Strack, D., and Matern, U., Biosynthesis of phenylpropanoids and related compounds, in Biochemistry of Plant Secondary Metabolism, Wink, M., Ed., Sheffield Academic Press, Sheffield, 1999, 151. 

Tamagnone, L. et al.. The AmMYB308 and AmMYB330 transcription factors from Antirrhinum regulate phenylpropanoid and lignin biosynthesis in transgenic tobacco. Plant Cell, 10, 135, 1998. 

Christie, P.J., Alfenito, M.R., and Walbot, V., Impact of low-temperature stress on general phenylpropanoid and anthocyanin pathways enhancement of transcript abundance and anthocyanin pigmentation in maize seedlings, Planta, 194, 541, 1994. 

Lahloub, M.F., Flavonoid, phenylpropanoid and iridoid glycosides of Linaria haelava (Forssk.) Dik, Mansoura J. Pharm. Sci., 8, 78, 1992. 

Wagner, Y.L.H. and Bauer, R., Phenylpropanoids and flavonoid glycosides from Lysionotus pauciflorus, Phytochemistry, 48, 339, 1998. 

Kang SM, Jung HY, Kang YM, Min JY, Karigar CS, Yang JK, Kim SW, Ha YR, Lee SH and Choi MS (2005) Biotransformation and impact of ferulic acid on phenylpropanoid and capsaicin levels in Capsicum annuum L.cv.P1482 cell suspension cultures. J Agric Food Chem 53 3449-3453... 

Figure 21.4 Phenylpropanoid and (iso)flavonoid pathway topology, subcellular localization and transport mechanisms. (Adapted from Winkel-Shirley, [2004], Kitamura, [2006] and Marinova et al. [2007b].)...

Phenylpropanoids and flavonoids found in plants are predominantly derived from the aromatic amino acid L-phenylalanine originated in the shikimic acid... 

Dixon RA, Choundhary AD, Dalkin K, Edwards R, Fahrendorf T, Gowni G, Harrison MJ, Lamb CJ, Loake GJ, Maxwell CA, Orr J, Paiva NL. 1992. Molecular biology of stress-induced phenylpropanoid and isoflavonoid biosynthesis in alfalfa. In Stafford HA, Ibrahim RK, Eds. Phenolic Metabolism in Plants. New York Plenum, pp. 91-138. 

Farag MA, Huhman DV, Dixon RA, Sumner LW. 2008. Metabolomics reveals novel pathways and differential mechanistic and elicitor-specific responses in phenylpropanoid and isoflavonoid biosynthesis in Medicago truncatula cell cultures. Plant Physiol 146 387 402. 

---