Plant immune system research ready for application
In the battle between diseases and plants -- constant, changing and centuries old -- scientists and farmers usually arm themselves through classical breeding, crossing varieties in the hopes of eventually reaching disease resistance. With advances in DNA sequencing and genetics, however, they may soon have a more sophisticated weapon: disease-resistant seeds.
Basic research on the genetic gears of plant immune systems has advanced so much that scientists can now begin applying that knowledge, building healthier plants to decrease dependence on pesticides, water overuse and help agriculture in developing countries, according to a paper in this week's edition of the journal Science.
"I think the backdrop is simple: We need to feed a lot of people, and we need to do it in a sustainable way," said Jeff Dangl, one of the paper's authors. He is a Howard Hughes Medical Institute investigator and biology professor at the University of North Carolina. "We need to feed them in a way that we use no more land than we use now. We need to do it more efficiently, and we need to do it in the face of ever-evolving pathogens."
The paper was also authored by Brian Staskawicz, plant and microbial biology professor at the University of California, Berkeley, and Diana Horvath, director of the Two Blades Foundation, a Chicago-area nonprofit promoting plant disease resistance research and application. NSF funds have helped fuel the research of all three.
The paper synthesizes two decades of research on plant immune systems, looking at "where technology has been applied, and what the future can be," said Staskawicz.
For more than a century, disease resistance in plants has been achieved through traditional breeding, a process that requires the "patience of Job," Dangl said. "Imagine waiting till you get to your grandchildren to see how your offspring turn out."
Disease-causing microbes multiply much, much faster. Modern agriculture--predominately single crops grown over many acres instead of the diversity hodgepodge seen in nature--also favors pathogens, microbial agents that cause disease.
Globally, about 15 percent of crop harvests are lost each year due to disease, but destruction varies greatly from crop to crop. Cassava blight, which attacks a staple food source in many developing countries, can destroy 20 to 100 percent of crops. Most loss occurs late in a crop's life, gallons and gallons and gallons of water in. "Plant diseases are a huge waste of water," Dangl said.