GM Grapevines May Soon be Planted in France

Updated: 20/09/2004

A new strain of grapevines resistant to Fanleaf disease may soon be planted in a test vineyard in Alsace, France. The project hopes that modified vines might improve vineyard health, raise wine quality and reduce pesticide use, as well resurrect the French wine industry, currently suffering from competition from emerging wine leaders South Africa, Australia, New Zealand, and South America.

Fanleaf disease is transmitted by the soil nematode Xiphinema index, which feeds on the roots of grape vines, transferring the Grapevine Fanleaf Virus (GFLV) from infected plants to otherwise healthy ones. The virus stunts vine growth, discolors grape leaves, and yields poor tasting fruit. It is estimated to affect more than 25,000 acres of vineyards in France, reducing crop yields by up to 80 percent for sensitive varieties such as Cabernet Sauvignon, Chardonnay, Gewürztraminer and Pinot Noir.

French winemakers fight the virus by spraying infected plants with nematicide, a pesticide so potent that its use in agriculture has been banned in countries such as Switzerland and Germany and in some U.S. states. According to Marc Fuchs, head of the GM project, "It kills all organisms in the soil, even the micro-organisms that play a big role in the biological life that forms terroir." Terroir refers to all the characteristics of a vineyard, including climate and soil quality, which impart quality to a particular wine.

The GM vines were altered in the laboratory through a process that would result in the vines' immunization to GFLV. A gene fragment, coding for the coat protein of the virus, is introduced into cells of healthy grapevine rootstock. This results in a mild infection, which the plant's immune system can combat, and which, once overcome, will render the grapevine immune to subsequent GFLV infections.

More studies on resistant grapevines are underway, including vines with bacterial chitinase genes, which may be able to fight fungal infections and even inhibit the growth of pathogens that cause Botrytis bunch rot and powdery mildew of grapes.

Some information on work being done on GFLV can be found at http://www.actahort.org/books/603/603_42.htm.