October 26, 2010

Transgenic Plants – Corporate or College?

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Ten years ago, genetically modified organisms (GMOs) emerged in the public forum as one of the major controversies in the plant breeding world. Transgenic plants – containing DNA from other organisms – are at the center of the controversy.

Cornell’s campus is a powerhouse of plant research, where transgenic plants are created. The College of Agriculture and Life Sciences contains the departments of plant biology, plant breeding & genetics, and horticulture, with labs and greenhouses in Ithaca and at the New York State Agricultural Experiment Station in Geneva, NY. The Boyce Thompson Institute (BTI), an independent non-for-profit organization for plant research with a world-renowned reputation, is near the Vet School.

Scientists have been developing transgenic plants at the university since the Green Revolution of the 1960s. One famous example is the GMO papaya, developed by Prof. Dennis Gonsalves, plant pathology. Gonsalves collaborated with scientists at the University of Hawaii and the USDA for nearly two decades to introduce a resistance gene into papaya – the genes combated a virus that destroyed Hawaiian papaya crops. The project succeeded, and the collaboration also marked the first time a university-pursued and approved deregulation – extensive testing and then approval by the US Department of Agriculture (USDA) for commercial use – of a transgenic fruit in 1996.

The landscape has changed for academic research on transgenic plants. Today, very little research on Cornell’s campus develops transgenic plants for commercial use.  Prof. Jim Giovannoni, plant biology, a USDA plant molecular biologist who works at BTI, studies the ripening pathways in tomatoes and fruit.

Though he works with these edible crops, “Most of the transgenic plants we make are to address questions of basic biology. In general, they’re not designed to create a product,” said Giovannoni.

Researchers in Giovannoni’s group create mutant tomatoes using Agrobacterium tumifaciens – a pathogenic plant bacterium that can inject DNA into plant cells – to introduce a transgenic DNA sequence made up of viral (cauliflower virus), microbial (Agrobacterium and antibiotic resistance markers), and mostly tomato DNA. They do this to manipulate the expression of specific genes.

Growth of transgenic plants in greenhouses at Cornell and BTI is tightly regulated to prevent the escape of pollen or plant materials. Screens cover block the entry of potential pollinators, and all plant material grown in a greenhouse with the transgenic plants, whether transgenic themselves or not, must be “rendered biologically inactive” by pressure-cooking in an autoclave before disposal, according to the Cornell Institutional Biosafety Committee form for greenhouse use.

Growing transgenic plants in field trials is even more tightly regulated, requiring a permit from the government, a minimum distance from commercially grown crops of the same plant, and swaths of land around the field to minimize the movement of transgenic material.

Prof. Tom Brutnell, plant breeding and genetics, a scientist at BTI, studies corn genetics. In one of his collaborative projects funded by The Bill & Melinda Gates Foundation, his group studies photosynthesis genes from C4 plants with the long-term goal of eventually engineering them into C3 plants, like wheat and rice. C4 plants have very efficient photosynthetic mechanisms that allow them to thrive in hot, dry locations. Brutnell’s group uses the model, non-crop plant Arabidopsis thaliana for much of their transgenic work. Part of the reason he uses model systems is the ease compared to using transgenic crop plants.

Brutnell said, “Many of the regulations on transgenic plants hamper their use in basic research.”

Once developed for commercial use, plants must be deregulated by the USDA and the Animal and Plant Health Inspection Service (APHIS).  This  is an expensive process, requiring extensive testing and data collection.

Prof. Margaret Smith, plant genetics & breeding, Associate Director for Cornell Cooperative Extension, follows genetically engineered crops closely. As a corn breeder, Smith doesn’t develop transgenic plants.  However, as part of her extension appointment, she educates audiences on and off campus about genetic engineering in order to demystify the technology.

According to Smith, “There’s still quiet a bit of interest in genetically engineered crops.” However, due to the high costs associated with technology use and deregulation, she added, “That interest is largely concentrated in the private sector.”

Original Author: Daina Ringus