Crop Biotech Update

Researchers Examine Plant's Ability to Identify and Block Invading Bacteria

March 5, 2010

Scientists from the Texas A&M University are conducting experiments to understand how plants defend themselves from bacterial infections. The researchers are interested in a specific bacterium that infects tomatoes but normally does not bother the common laboratory plant Arabidopsis. Understanding how infection is selective in various organisms will not just allow researchers to develop improved plant varieties but may also help understand how people and other animals could be better protected from pathogens.

"By learning what is wrong with a sick plant we can study how a plant can defend itself, what mechanisms it uses for protection," said Hisashi Koiwa, leader of the study. Koiwa and colleagues are looking at molecular components of the plant immune system: N-glycans, receptors and ligands. N-glycans are polysaccharides that are critical in protein folding, a natural process which if it becomes unstable leads to various diseases. A receptor is a protein decorated with N-glycans which awaits signals from the ligands that bind and activate receptor molecules.

Studying Arabidopsis plants with mutated N-glycans, Koiwa discovered one particular N-glycan that was critical in making sure that the receptor molecules can recognize the targeted bacteria molecule. "If that polysaccharide can recognize a pathogen, it can prevent infection thus making the plant immune to that disease," the scientist noted. Koiwa added that using this approach to develop new plant varieties that do not allow pathogens inside the cells would be better than breeding lines that are merely "resistant" to diseases.

Read http://agnews.tamu.edu/showstory.php?id=1788 for more information.