Genetic profile could help in breeding new disease-resistant or health-giving varieties
The genome of the grapevine, Vitis vinifera, has been decoded by scientists from - where else? - France and Italy.
The research reveals the genetic origins of certain aromas and health-promoting compounds in wine, and may help scientists to breed varieties which are disease-resistant or particularly rich in certain flavour compounds.
The team selected a grapevine variant derived from Pinot Noir cultivates, and deciphered the genome using standard ’shotgun’ sequencing - a technique which effectively blasts the DNA strands into fragments which are read individually, before the information is reassembled like an enormous jigsaw.
The grapevine they used was specifically bred to have high homozygosity, so that both copies of each chromosome pair carried the same version of most of the plant’s genes. Many grapevine variants have remarkably high (up to 13 per cent) numbers of genetic differences between a pair of chromosomes, which would make the established method of shotgun sequencing extremely difficult.
This is only the fourth genome sequence of a flowering plant (after Arabidopsis cress, rice, and poplar), but the information has already helped the scientists to draw up a rough ’family tree’ showing the evolution of these flowering plants.
The first analyses of the grapevine genome has found that the stilbene synthase enzymes (STSs) that are responsible for the synthesis of resveratrol, a phenol derivative that has been linked to the health benefits of moderate wine consumption, are represented by a hugely inflated number of genes. The researchers found 43 STS genes, of which at least 20 are known to be active.
Anne-Francoise Adam-Blondon from the National Institute of Agronomic Research in Versailles-Grignon, France, who was part of the research team, thinks that the research could lead to ’the development of high quality grapevine cultivars resistant to diseases, contributing to the much-needed reduction of fungicide and pesticide treatments’.
Scientists could also use the genome information to develop cultivars producing high level of health-giving compounds for fruit juice production, she told Chemistry World.
Enzymes associated with aromas are also well represented in the genome, compared with other plants. Terpene synthases (TPSs) are involved in a plant’s interaction with its environment, but in the grapevine they are also responsible for aromas.
The other three plants that have been sequenced have between 30 and 40 genes to make these synthases; the grapevine boasts 89 functional TPS genes and 27 pseudogenes. It appears that the rich variety of flavours found in wines is deeply rooted in the genomics of the grapevine.
The French-Italian Public Consortium for Grapevine Genome Characterization, Nature, 2007, DOI: 10.1038/nature06148.