Genetically modified grapes or other ingredients of wine need thorough airing of pros and cons before introduction and already have strikes against them, according to an international panel of speakers at the recent Wine and Grape Unified Symposium in Sacramento.

In setting the scene for the discussion, Carole Meredith, professor of viticulture at the University of California, Davis, said the question of genetically modified organisms (GMOs), wine grapes or otherwise, is global in scope.

Among the concerns surrounding it are benefits to consumers, the necessity of changes, the process of understanding of divergent views.

“If we are going to consider a role for this technology, we have to be ready for it and fully informed of what it can and cannot do,” Meredith said.

Linda Bisson, professor of enology and genetics at UC, Davis, called for viewing the “big picture” of genetic engineering.

She defined genetic engineering as an artificial process to change plant or animal genetics, directing them in a desired way. The process accelerates spontaneous and natural changes made over time.

Sources of genes can be from the same species, a related species, or an unrelated species, or they can even be from synthetically produced proteins assembled into DNA building blocks.

The “most gentle approach” is to change an existing gene to improve a trait in an organism. Classical breeding to accomplish this may take two to three years, but genetic engineering may require as little as two weeks.

In the world of physics, Bisson said, for every action there's a reaction. However, she added, in the world of biology every genetic action can cause thousands of genetic reactions.

“As long as we are aware of this and we take measures to figure out what is the impact of the genetic exchange, then I think this technology can be applied safely. It is only dangerous when people think too narrowly and don't understand the possible reactions,” she said.

Yeast genus

The numerous examples of genetic manipulations of organisms are aimed at increasing profitability. Bisson is a specialist in the yeast genus Saccharomyces, which she calls “the premier organism for genetic engineering” because its structure is easily manipulated.

Among issues involved in this science is the potential for lateral transfer of a gene from one organism to another, such as bacteria developing resistance to a drug.

The link between recombinant DNA technology and wine production is that groups of genes can be replaced in strains of winemaking yeasts to govern production of chemical components.

The technology can eliminate problems of hydrogen sulfide, stuck fermentation, and lactic acid, and help produce desired flavors and aromas. Yet cross-contamination that could produce different styles of wine still poses risks.

Applications of genetic engineering in grapes will not become widely accepted overnight, but plant breeders need to start experiments and test methods before plants are passed to growers, said panelist Reinhard Toepfer, director of the Federal Grapevine Breeding Institute in Geilweilerhof, Germany.

The point of view of grape breeders in Germany is to let consumers decide whether to continue with chemical crop protection or to turn to genetic engineering to improve varieties.

Wide-ranging research

The practical priorities of genetic engineering of grapes, he said, are achieving resistance to insects, diseases, and nematodes. Research, in a dozen countries including the U.S. and Germany, is moving on both the classical and biotech fronts to produce new varieties with desired traits such as resistance to disease caused by fungi.

One “new” variety from his institute, Regent, similar to Pinot Noir, came from classical crosses made in 1967 but was not released until 1997 after extensive testing. Plant protection costs for it were reduced by 80 to 100 percent.

Among genetic engineering projects for resistance in grapes around the world, he said 15 address viruses, eight deal with fungi, and four focus on agrobacteria. He added that classical breeding is not adapted to modifying vines for improved virus resistance.

Exploring the role of genetic engineering from the perspective of a wine exporter, Australian grower Peter Hayes said GMOs concern more than half the consumers in his country as reflected in food-safety polls.

He proposed the wine industry hear out GMO critics, understand diversity of views and prepare for compromise.

“In finding a way forward, industry should look at determining a policy of strategy for research, development, evaluation and potential production of GMOs,” he said.

That would involve open and clear dialog, information and education, ethical and professionally sound research, and formalized identification of the benefits and hazards of GMOs.

Both genetically modified and conventional production systems should be measured by the same rigorous standards.

Exporters, he said, rely on consistent rules and regulations, and none will introduce a technology to the market without significant benefit to the consumer. Hayes urged national and international cooperation on GMO product development.

Consumer demands

British food and wine writer Fiona Becket said consumers will demand to know what goes into modern wines. Meanwhile, GMOs already have a negative image in the general media and no support from the wine media in the United Kingdom.

The only possible positive area for GMOs she can see, she said, is if they were to be shown to improve health, such as causing a reduction in heart disease.

Wine, in particular, is closely linked with natural processes in the consumer psyche.

For the moment, the “Frankenstein Food” label, taken from a tabloid newspaper years ago, reflects the general perception of GMOs among British consumers, she said.

Compounding the negative perceptions are mad-cow publicity in the UK, causing the public to doubts its government, and several books attacking GMOs.

Polls in the UK, she said, indicate that 70 to 90 percent of the public opposes GMOs.

E-mail: dan_bryant@intertec.com