'Suicide Response' Gives Colorado State Researchers Important Clues On Preventing Bacterial Invasion In Crops...( FORT COLLINS--Colorado State Univer...)

FORT COLLINS--Colorado State University scientists have made an important breakthrough in studies of bacteria that cause disease in crops worldwide but whose basic functions have eluded researchers for years.

The breakthrough proves that plants use an arsenal of gates and passwords to defend themselves against a group of gram-positive bacteria--known as club-shaped bacteria--the same way they defend themselves against other types of bacteria. The discovery could ultimately lead to the development of genetically-engineered crops that resist a wide range of diseases.

The study centered on bacteria that causes ring rot in potatoes, a disease that spawns millions of dollars in prevention and treatment costs on American farms each year. A single plant with symptoms of ring rot infection in a field of potatoes can cost a farmer as much as $80,000 in lost revenue. Because ring rot spreads so quickly and potato plants have zero tolerance for the disease, potatoes grown in the United States must be inspected and certified disease-free before being shipped out of state or overseas.

When this bacteria encounters its potato plant host, a series of complex interactions take place that signal the bacteria to invade and infect the plant. In their study, Colorado State researchers found that plants that are not specific hosts for these gram-positive bacteria display a much different reaction known as a suicide response. Like an internal quarantine, the plant protects itself from bacterial invasion by killing its own cells and surrounding the bacteria, thus cutting off the potential for disease. The Colorado State project documented this response in tobacco plants exposed to the potato ring rot bacteria.

While the suicide response has been documented in plants exposed to another group of well-known bacteria called gram-negative bacteria, Colorado State researchers were the first to
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Contact: Carrie Schafer
CSchafer@vines.colostate.edu
(970) 491-6432
Colorado State University
6-Jan-1998