Researchers suggest that DNA of organisms exposed to stress undergo changes in DNA methylation patterns that alter how genes are regulated.
Technically, scientists found that exposure to a pathogenic bacteria caused widespread changes in a plant’s epigenetic code.
“In different stress conditions — flooding, drought, chilling, wounding or pathogen attack — ethylene tells plants to make adjustments to these adverse changes,” said senior study author Joseph Ecker, a professor in Salk’s Plant Biology Laboratory and Howard Hughes Medical Institute-Gordon and Betty Moore Foundation investigator.
The research findings, published in Science magazine’s August issue, may hold the key to manipulating plants ethylene on/off switch, allowing them to balance between drought resistance and growth. The results might deter crop losses and aid in a plant’s ability to bear fruit.
The article points out that stress conditions can cause wilted leaves, premature aging and spoilage from over ripening
“Growers can opt to spray their plants with the ethylene inhibitor,” said Hong Qiao, a postdoctoral researcher in Ecker’s laboratory and first author of the paper. “This blocks the plant’s ethylene receptors from smelling ethylene, which has an effect on growth.
“Without the ethylene response pathway, a tomato would never ripen. Too much ethylene and the tomato over ripens. Therefore, basic knowledge of the precise mechanism by which plants control the response to ethylene gas will lead to better ways to control these processes in crop plants.”
It was long thought that methylation, a crucial part of normal organism development, was a static modification of DNA that could not be altered by environmental conditions.
More than 30 to 40 percent of annual crops are lost to pathogens each year at a cost of some $500 billion.
The U.S. is undergoing its most severe drought in 25 years, which could wipe out farmers’ incomes and raise food prices. Researchers are studying stress conditions in hopes of improving crop production.