The inventors are Roger Beachy, Ph.D., president of the Donald Danforth Plant Science Center, and professor in the department of biology in Arts & Sciences at Washington University, and Robert T. Fraley, Ph.D., Monsanto chief technology officer and former Monsanto research scientist Stephen G. Rogers.
Over the past 16 years, ongoing research and development in laboratories around the world has led to virus-resistant varieties of tomato, pepper, cucumber, squash, sugar beets, papaya and plum, among other crops. Recently, scientists at the University of Hawaii and their collaborators used the technique to develop disease-resistant varieties of papaya to protect against papaya ringspot virus. Beachy and his collaborators are researching viral resistance in numerous other plants, including rice and cassava.
Monsanto has donated rights to the technology to a number of public institutions.
"The sharing of this technology has been critical in creating virus-resistant crops for developing countries around the world," Fraley said.
In addition to the successes in papaya, Monsanto is collaborating with the Danforth Center and the Kenya Agricultural Research Institute to develop a virus-resistant sweet potato.
"We are delighted that this technology, as one of the first applications of biotech, is helping to advance science throughout the globe," Fraley said.
The technique was conceived, developed and tested in the 1980s when Beachy was professor of biology at Washington University. The research began in the early '80s with attempts to make tobacco plants resistant to a virus called tobacco mosaic virus (TMV). This involved constructing target genes containing a viral-coating protein and inserting them into tobacco leaf tissue. Plants regenerated from this tissue were able to resist the virus. In 1987, they tried the technique with tomatoes and became the first team to successfully genetically engineer a food crop with a disease resistance trait.
"The creation of disease-resistant plants will bring benefits throughout the world, thanks to the pioneering work of Beachy and our many other outstanding biology faculty and their scientific colleagues at Monsanto. This discovery is another example of St. Louis's emerging role as a world leader in plant research and the exceptional history of collaboration between this university and industry," said Mark S. Wrighton, Washington University chancellor.
The group of scientists developed a gene that, when introduced to plant cells, would cause the cells to produce the virus "coat," a protein normally made by the virus to ensheath the virus's genetic information. Tomato plants that were produced from the modified cells – transgenic plants – produced the coat protein in very small amounts in comparison to the amount of coat protein that is produced during virus infection. While these plants were "challenged" by tobacco mosaic virus inoculation and its close relative, tomato mosaic virus, they were highly resistant to infection. Work conducted since the original discovery has demonstrated that the "coat protein" in the transgenic plants restricts infection and thwarts the ability of the virus to successfully infect the plant.
Aphids spread many different types of plant viruses, and it is common practice to control virus infection by using chemical insecticides to limit spread of viruses. The "coat-protein mediated resistance" technology, like other disease resistance genes, can substantially reduce farmers' reliance on chemical insecticides. Therefore, this technology has helped solve an otherwise unsolvable problem in agriculture.
With the granting of this patent, Monsanto can continue to license the patent to interested parties.
"It is gratifying to see the technology we developed nearly two decades ago reach this stage and have the impact that it has had and will have on agriculture throughout the world," said Beachy. "The technology already has reached many people and has been proven effective for many different crops. What's truly exciting is its potential to increase food production in developing countries."
Beachy, a member of the National Academy of Sciences, is internationally known for his groundbreaking research on virus-resistant plants. He is the founding president of the not-for-profit Donald Danforth Plant Science Center in St. Louis, Mo., a position he has held since January 1999. In this role, Beachy has been responsible for developing and implementing the Danforth Center's strategic direction, recruiting its staff, and formulating its research programs. The Center, established in 1998, is affiliated with many businesses and universities and focuses on interdisciplinary research in genetics, chemistry, cell biology, biochemistry, computational genomics and structural biology.
From 1991 to 1998, Beachy headed the Division of Plant Biology at The Scripps Research Institute, a leading biomedical research center in La Jolla, California. He was also Professor and Scripps Family Chair in Cell Biology and co-director of the International Laboratory for Tropical Agricultural Biotechnology (ILTAB) at Scripps.
Beachy was a member of the biology department at Washington University in St. Louis from 1978 to 1991, where he was Professor and Director of the Center for Plant Science and Biotechnology. He rejoined the department in 1999 upon his appointment to the Donald Danforth Plant Science Center.
Research under Beachy's direction has led to a number of patent applications. He has edited or contributed to 50 book articles, and his work has produced more than 200 peer-reviewed publications.
Fraley oversees Monsanto's crop and seed agribusiness technologies and research platforms with facilities in almost every world area. He has authored more than 100 publications and patent applications relating to technical advances in agricultural biotechnology. Fraley received the National Medal of Technology from President Clinton in 1999.