A comparison of stilbene and chalcone synthases including a new stilbene synthase gene from Vitis riparia cv. Gloire de Montpellier

Abstract

A stilbene synthase gene was cloned from Vitis riparia cv. Gloire de Montpellier after PCR amplification with primers designed to include the start and stop codons of stilbene synthase genes of V. vinifera. The exon was very similar to that of other stilbene synthases, particularly those from V. vinifera (99% nucleotide identity). An intron was found which interrupted the predicted codon for cysteine in the same location as in other stilbene and chalcone synthase genes. The intron showed high nucleotide identity (86%) with an intron from a stilbene synthase gene of V. vinifera. The V. riparia sequence was used in an evaluation of the relatedness of stilbene and chalcone synthases of plants. Five procedures involving distance, parsimony and maximum likelihood methods were used for constructing phylogenetic trees, and they yielded slightly to considerably different results. However, none of the trees were consistent with a previous hypothesis that stilbene and chalcone synthases cluster solely based on the genetic relatedness of the species, implying that stilbene synthase genes arose independently in plant families. In our analyses, stilbene and chalcone synthases of Vitis always clustered separately. The relatedness and origin of stilbene and chalcone synthases appears to be more complex than originally believed.