Understanding grapes’ DNA could be the first step to disease resistance in vines or enhancing the flavors and aromas of wines
While we’ve had the genetic code of the human being and the fruit fly figured out for years now, grapevines and their fruit have had to wait further back in the DNA-mapping queue. But on Aug. 26, a team of Italian and French researchers reported on the website of Nature magazine that they have cracked the genetic code of the Vitis vinifera grape, meaning that winemakers may someday have greater control over the flavors and aromas in their wines.
According to Institut National de la Recherche Agronomique (INRA) researcher and spokesperson Anne-Francoise Adam-Blondon, the researchers discovered surprisingly large «families» of genes directly related to the production of tannins as well as terpenes, the compounds responsible for flavor and aroma in plants. This means that down the road, winemakers could possibly, for instance, purchase grapes and vines «made to order» in terms of flavor and aroma profile.
«The important aspect of this work is that it provides a more detailed roadmap of the grape to scores of researchers all over the world,» said UC Davis emerita and internationally known grapevine geneticist Carole Meredith. She also makes Syrah with her husband, Steve Lagier, under the Lagier Meredith label, on the slopes of Mt. Veeder in California’s Mayacamas mountains, looking down on the Napa Valley.
Meredith added that while the discovery could lead to the genetic manipulation of the vine, either molecular or conventional, «the biggest impact is in the better biological understanding of all the functions in a grapevine that are of interest to producers, consumers, writers and researchers.»
For example, in addition to the large gene families related to flavor, researchers discovered similar large families of genes related to the production of resveratrol, the compound generally credited with imparting many of the heart-healthy and anticancer qualities attributed to red wine. Knowing the grape genome may open the door to researchers to raise the resveratrol content of any given grape variety, thus potentially increasing the resulting wines’ healthy properties.
There could be agricultural benefits as well. The new information may make it possible to alter vines for greater disease resistance, perhaps inserting genes for resistance to Pierce’s disease, a virus that kills grapevines. Native American species tend to be resistant to the disease, so their resistance gene could possibly be worked into vinifera varieties, the species to which most wine and table grapes belong. According to Adam-Blondon, researchers are already working on developing resistance to powdery mildew, a disease that plagues winegrowing regions around the world.
While the possibilities are endless, the door has just been opened, however. «With the completion of the grape genome, a huge number of new approaches to improving grapes can be undertaken,» said Andrew Walker, a grape breeder at UC Davis. «The work may not go quickly, but there are now new approaches to intractable problems.»