Cloning And Expression Of The Resveratrol Synthase Gene From Polygonum Cuspidatum

Resveratrol is a natural polyphenol compound found in various plants like peanuts, grapes, Polygonum cuspidatum, etc. It is reported that it has a variety of biological and pharmacological properties, such as anti-cancer, anti-inflammation, cardio-protective activities. It is assumed to be a healthy to take food containing high content of resveratrol like wine and peanuts. Resveratrol also plays important roles in defending stresses to plants.Resveratrol synthase (RS; EC 2.3.1.95), the key enzyme in biosynthesis of stilbene-type phytoalexins, catalyzes the formation of resveratrol from one molecule of coumaroyl-CoA and three molecules of malony-CoA which come from phenylalanine metabolism pathway. Phenylalanine metabolism pathway is found in almost any plants, whereas resveratrol is only present in rare species which contain RS. Plants lacking of RS gene may be charged with the ability to synthesize resveratrol by transferring foreign RS gene into the plants, providing them with improved nutritional value and ability in defending microorganism infection.In this paper, A RS cDNA (PCRS) was cloned from medicinal plants P. cuspidatum using RT-PCR and GeneRacer methods. A full-length encoding region of RS sequence, a sequence (PCRS11) lacking a 72 bp as compared with PCRS, and a sequence contains two introns were obtained from the genomic DNA of P.cuspidatum. PNRS gene (obtained from peanuts), PCRS and PCRS 11 from P.cuspidatum were expressed in prokaryotic cells and in plant cells. When expression was performed in prokaryotic cells, PNRS and PCRS could be successfully expressed and translated into proteins, whereas no proteins could be detected when PCRS11 was induced to express. In comparison, when expressed in plant cells, plant expression vectors pCAMBIA3301-PNRS,pCAMBIA3301-PCRS and pCAMBIA3301-PCRS11 were constructed by replacing the GUS gene in pCAMBIA3301 with PNRS, PCRS and PCRS11, respectively. The vectors were then used for Nicotiana tabacum transformation via Agrobacterium-mediated transfer methods. PCR and RT-PCR tests showed that the target genes had been successfully integrated into the tobacco genome in all the transformants.But no resveratrol could be detected by HPLC.