Scientists in Uruguay have announced that they have uncovered the genetic make-up of the tannat grape, which is considered to be the best variety for a healthy heart.
Tannt is the signature variety of Madiran in south-west France and Uruguay. By unraveling the information in its genes and DNA, the researchers hope that their findings will help winemakers to produce even better-quality wines in the future.
"Winemaking has always been an art; today it is also a science," says Professor Francisco Carrau, of the United Nations University-BIOLAC program in Montevideo, who collaborated with an Italian team.
"If we can determine through biotechnology the factors that determine a wine's aroma and color, we can potentially apply that information to create more pleasing and valuable products."
Wine made from the tannat grape has twice the tannins of cabernet sauvignon, merlot or pinot noir, according to the researchers.
Its high concentration of tannins – anti-oxidants that combat the aging of cells – is partly attributed to the grape's many seeds.
The author of "The Red Wine Diet," Professor Roger Corder, discovered that wines produced from tannat contain high levels of procyanidins (three to four times more than cabernet sauvignon), which can reduce blood pressure, lower cholesterol and encourage healthy blood clotting.
Now that the genetic composition of the grape has been unpicked, the Uruguayan team has turned its attention to the way that environmental factors such as soil, climate and altitude affect the expression of genes in grapes. They are also studying the chemistry of wine's aromas and color.
"Such information can valuably guide decisions about where to plant new vines, which typically produce their first fruit after five years and their best fruit in about a decade. Having the ability to predict successful vineyard location holds enormous value," said Carrau.
The tannat genome sequence will also give producers a better understanding of the grape's inherited characteristics – a useful tool in future vine improvement. In addition it is expected sequencing grapes and other crops will provide a breakthrough in growers' ability to characterize and select genes involved in disease resistance – potentially reducing the need for chemical spraying.
Scientists in Australia, meanwhile, report that the cost of genome sequencing is dropping dramatically. Dr. Anthony Borneman, of the Australian Wine Research Institute (AWRI), told a recent wine industry conference that since 2005 the cost had fallen tenfold every 18 months.
"A $200,000 yeast genome that we did in 2006, we can do now for $500," he said.
Grapevine genomes were challenging because of their [data] size, but they were doable, Borneman said, adding that the AWRI was currently sequencing a number of chardonnay clones. In 2008, the institute's scientists were the first in the world to crack the genetic code of a Saccharomyces cerevisiae wine yeast.
“Today, we are unlocking the potential of yeast for winemakers, using genes to our advantage without resorting to genetic engineering,” said AWRI managing director Professor Sakkie Pretorius at the time.
Like Carrau, Borneman believes that the science of genomics has huge potential for the wine industry, through its ability to unlock "a lot of potential applications that were just too expensive to do even a year ago.
"It becomes a really cheap way to get hard data on your wine production, whether it's your ferments, your vineyard soil, or your pest and disease," he said. These include the ability to predict wine-associated phenotypes, and to look at genetic diversity in yeasts and grapevines.
Winemakers can "use the genome as a marker for how the organism is going to act in a wine environment," explained Borneman. "You can assess whether you are going to get a good wine."