Field trials are currently under way, says Maurice Moloney, director and chief executive of the Rothamsted centre. “In the greenhouse it's been very successful,” he says. “If we can get it to work in the field, we'll be able to optimize it to make it a robust trait” suitable for large-scale deployment. From there, says Maloney, the team hopes to expand its efforts, searching for naturally evolved protections and deterrents in other crops, and working out how these might be enhanced or modified to fight particular pests. “For example, you could have a volatile chemical that also is a deterrent for caterpillars, stem borers and the like,” says Maloney. “Potentially, if we can get this to work, the range of applications is phenomenal.”
Many GM-organism researchers are pushing work on crops sometimes neglected by the big agricultural companies. In the plant biotechnology group at the Swiss Federal Institute of Technology in Zurich, for example, Herve Vanderschuren leads a team working on cassava (Manihot esculenta), a tropical shrub with a tuber that is a staple food in the developing world. “There is not major investment in breeding or improvement of this crop,” he says.
Vanderschuren and his team are genetically engineering cassava to be resistant to two particularly damaging viruses, by starting with a variety that is naturally resistant to cassava mosaic virus, and then inserting genes that confer resistance to cassava brown streak virus. The naturally resistant strain was already tailored to local needs and markets. That kind of local adaptation is a “very important part of the research we do here”, says Vanderschuren — and something that is rarely embraced by huge agribusinesses that want to sell products worldwide. Vanderschuren and his team have successfully made the plants, and are now collaborating with colleagues in Africa to arrange tests to confirm that the cassava can be grown in the field.
Much of the work on crops in developing nations focuses on nutritional enhancement. The most famous example of this effort is Golden Rice, a modified version of the staple food of half the world. Its distinct yellow hue comes from the addition of β-carotene, a precursor to vitamin A that is deficient in many East Asian diets. After much painstaking development and many objections from opponents of GM organisms — the original version of Golden Rice was announced in 2000 — the crop is currently undergoing field trials in the Philippines (see I. Potrykus Nature 466, 561; 2010). It could clear the final regulatory hurdles and reach farmers by 2014.
Others have followed in its wake. James Dale, director of the Centre for Tropical Crops and Biocommodities at Queensland University of Technology in Brisbane, Australia, for example, is trying to equip bananas with resistance to Panama disease, a fungal wilt that can devastate crops, as well as increased β-carotene and a suite of other nutrients including iron. “Levels of micronutrient deficiencies are really very high” in Uganda and all across Africa, he explains, and bananas are a staple of the diet. Field trials have already been conducted in Australia.
Although most next-generation GM organisms are aimed at farmers, some target the next step in the chain: industrial food processors. For example, Chris Dardick, a molecular plant biologist at the US Agricultural Research Service's Appalachian Fruit Research Station in Kearneysville, West Virginia, explains that it is difficult to get plums into processed foods, because removing their hard, woody cores leaves shards behind. But starting with genes from a mostly stoneless, conventionally bred plum, Dardick and his team are in the early stages of engineering a fruit with no stone at all. “Our biggest concern was how such a thing would be embraced by industry and consumers. Most of the feedback we've gotten has been quite positive,” he says.