TORONTO, Feb. 28 (UPI) -- Scientists have identified several key proteins that play an important role in how bacteria infect plants, a finding that could help researchers develop ways to prevent infections, according to a new study released Thursday.
Researchers led by geneticist David S. Guttman, of the University of Toronto in Canada, developed a genetic screening test to single out these critical proteins in a plant-invading bacteria called Pseudomonas syringae, a common foe to soybeans, peas, cucumbers and tobacco plants.
"It is a serious pathogen on a wide range of agricultural species," Guttman told United Press International, "and (it) could cause significant crop damage."
Some bacteria use a particular channel to infect its host and that channel is called a type III secretion system. Three other bacteria that use this channel, salmonella, a common culprit of food poisoning, Yersina pestis, a bacterium that causes plague, and Chigella, which causes dysinteria.
Screening this channel, researchers identified 38 of these proteins, called type III effectors. In essence, Guttman explained, this bacterial channel is like a cannon and these proteins are the cannon balls infecting the plant.
"If you were to knock out the system, the bacteria are no longer pathogens," he said. The organisms would be unable to infect, which means this channel and these proteins, Guttman added, could be potential targets for bacteria-fighting drugs.
Researchers also found variations among these proteins, suggesting bacteria may use multiple strategies to adapt to what it is infecting. Guttman said scientists are investigating whether these strategies may evolve over time.
"I believe by understanding what the proteins are that the bacteria uses, then we can better understand how the bacteria adapts to its host," Guttman said.
The findings are published in Friday's issue of Science.
Guttman said identifying such proteins could have a biotechnology benefit as scientists can genetically engineer plants to develop stronger defense mechanisms against the bacteria.
In a separate study published in Thurday's issue of Nature, researchers at Massachusetts General Hospital in Boston are investigating the efficacy of defense mechanisms plants use to protect themselves against bacteria and fungi.
They discovered a crucial molecular pathway in plant cells used to ward off invading pathogens, suggesting the pathway could be activated in plant leaves, making it more resistant to pests.
"Now we know what we can do to boost the plant's immune system" Jen Sheen, lead researcher, told UPI.
Sheen also said identifying the type III effectors is potentially a new way to approach disarming bacteria.
"The bacteria, when they want to send toxins into plant cells...they would go through a special channel," Sheen said.
So by combing through what passes across that channel, she explained, "then maybe they would be able to prevent bacteria from doing that."
(Reported by Katrina Woznicki in Washington)
