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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., (© 2010 International Union of Biochemistry and Molecular Biology, Inc.)

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.

Abstract: A cell suspension culture was developed from calli of grape rootstock 41B in order to study the bioproduction of resveratrol. While 41B grape cultures produced no resveratrol, methyljasmonate (MeJA) elicitor treatment activated its production in a dose dependent manner. The concentration of 0.2mM MeJA was optimal for efficient production and high accumulation of resveratrol (150mg/L) in flask experiments. Microscopic analysis of cells monitored for viability showed that MeJA elicitor triggered expression of resveratrol fluorescence within the cells. These results led to scale-up of the culture in a 2L stirred bioreactor where a resveratrol production of 209mg/L being secreted into the liquid medium, corresponding to 90% of the total production. Liquid/liquid extraction of the culture medium and a solid/liquid extraction of the cells showed that other stilbenes were also produced. For the first time, trans-ɛ-viniferin, trans-δ-viniferin, and a trans-3-methylviniferin as well as trans-piceatannol were identified in a 2L bioreactor cell cultures of grapevine. Furthermore, a one step FPLC method was developed for the purification of resveratrol and ɛ-viniferin. [Copyright &y& Elsevier]