Stilbenic compounds recently have become the focus of a number of studies in medicine and plant physiology as well as have emerged as promising molecules that potentially affect human health. Stilbenes are relatively simple compounds synthesized by plants and deriving from the phenyalanine/polymalonate route, the last and key enzyme of this pathway being stilbene synthase. Here, we review the biological significance of stilbenes in plants together with their biosynthesis pathway and their metabolism both by fungi and in planta. Special attention will be paid to the role of stilbenic molecules as phytoalexins.

Biosynthesis, metabolism, molecular engineering, and biological functions of stilbene phytoalexins in plants.

Plants as bioreactors: Recent developments and emerging opportunities.

The grapevine phytoalexin resveratrol, the synthesis of which is achieved by stilbene synthase (STS), displays a wide range of biological effects. Most interest has centred, in recent years, on STS gene transfer experiments from grapevine to the genome of numerous plants. This work presents a comprehensive review on plant molecular engineering with the STS gene. Gene and promoter options are discussed, namely the different promoters used to drive the transgene, as well as the enhancer elements and/or heterologous promoters used to improve transcriptional activity in the transformed lines. Factors modifying transgene expression and epigenetic modifications, for instance transgene copy number, are also presented. Resveratrol synthesis in plants, together with that of its glucoside as a result of STS expression, is described, as is the incidence of these compounds on plant metabolism and development. The ectopic production of resveratrol can lead to broad-spectrum resistance against fungi in transgenic lines, and to the enhancement of the antioxidant activities of several fruits, highlighting the potential role of this compound in health promotion and plant disease control.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1467-7652.2008.00377.x

Molecular engineering of resveratrol in plants.

https://www.cell.com/trends/biotechnology/pdf/S0167-7799(07)00317-4.pdf

Potential for metabolic engineering of resveratrol biosynthesis

Resveratrol, a stilbenic compound deriving from the phenyalanine/polymalonate route, being stilbene synthase the last and key enzyme of this pathway, recently has become the focus of a number of studies in medicine and plant physiology. Increased demand for this molecule for nutraceutical, cosmetic and possibly pharmaceutic uses, makes its production a necessity. In this context, the use of biotechnology through recombinant microorganisms and plants is particularly promising. Interesting results can indeed arise from the potential of genetically modified microorganisms as an alternative mechanism for producing resveratrol. Strategies used to tailoring yeast as they do not possess the genes that encode for the resveratrol pathway, will be described. On the other hand, most interest has centered in recent years, on STS gene transfer experiments from various origins to the genome of numerous plants. This work also presents a comprehensive review on plant molecular engineering with the STS gene, resulting in disease resistance against microorganisms and the enhancement of the antioxidant activities of several fruits in transgenic lines.

/pdf/metabolic-engineering-of-yeast-and-plants-for-the-production-zt63cskrmj.pdf

Metabolic Engineering of Yeast and Plants for the Production of the Biologically Active Hydroxystilbene, Resveratrol

Resveratrol (trans-3,5,4'-trihydroxystilbene) is a plant phytoalexin which has positive effects on human health. Stilbene synthase (STS) is a key enzyme involved in resveratrol biosynthesis. To construct a vector for STS expression in lettuce plant, a cDNA-encoding STS of Parthenocissus henryana was fused to the Cauliflower mosaic virus (CaMV) 35S promoter, and the bar gene was used as a selective marker gene. To increase the expression of STS, the expression cassette was flanked by MARs. In transgenic lettuce plants, an additional compound was identified as resveratrol by HPLC and ESI-MS. Quantitative analysis showed that the average content of resveratrol reached 56.40 +/- 5.52 microg/g leaf fresh weight, which was comparable to the amount in grape skin. Anticancer assay in HeLa cells revealed that apoptosis was induced by 200 microM of resveratrol extracted from transgenic lettuce.

High content of resveratrol in lettuce transformed with a stilbene synthase gene of Parthenocissus henryana

Cinnamate 4-hydroxylase (C4H, EC 1.14.13.11) plays an important role in the phenylpropanoid pathway, which produces many economically important secondary metabolites. A gene coding for C4H, designated as PhC4H (GenBank accession no. DQ211885) was isolated from Parthenocissus henryana. The full-length PhC4H cDNA is 1,747 bp long with a 1,518-bp open reading frame encoding a protein of 505 amino acids, a 40-bp 5' non-coding region and a 189-bp 3'-untranslated region. Secondary structure of the deduced PhC4H protein consists of 41.78% alpha helix, 15.64% extended strand and 42.57% random coil. The genomic DNA of PhC4H is 2,895 bp long and contains two introns; intron I is 205-bp and intron II is 1,172-bp (GenBank accession no. EU440734). DNA gel blot analysis revealed that there might be a single copy of PhC4H in Parthenocissus henryana genome. By using anchored PCR, a 963-bp promoter sequence was isolated and it contains many responsive elements conserved in the upstream region of PAL, C4H and 4CL including the P-, A-, L- and H-boxes.

Isolation and characterization of a gene encoding cinnamate 4-hydroxylase from Parthenocissus henryana

This invention has clone Stilbene synthase gene (sts) from Parthenocissi Tricuspidatae endogeny eumycete, the coding sequence similarity between Stilbene synthase gene and Parthenocissi Tricuspidatae is 95.25%,this eumycete belongs to Cladosporium sp by 18SrDNA series assessment. High performance liquid chromatogram and mass chromatographic analysis indicate that this eumycete can also composite resveratrol by culture in vitro. The analysis about non- coding part of endogeny eumycete sts gene indicates that: it is very different from regulatory element of sts gene which is in plants. Importing exogenous gene(such as VHb,ipt and iaaM and so on ) in endogeny eumycete can promote endogeny eumycete growing.

Shujun Liu

Papers

High content of resveratrol in lettuce transformed with a stilbene synthase gene of Parthenocissus henryana

Isolation and characterization of a gene encoding cinnamate 4-hydroxylase from Parthenocissus henryana

Cladosporium endogenic fungus capable of producing veralkol