Scientists Find Proteins that can Dampen an Overactive Plant Immune System

Plants have their own version of the immune system, and pretty much like the human immune system, it is very prone to overreacting. If the system overreacts to pathogens, it can stunt plant growth and reduce seed production. Researchers at the University of Minnesota identified important suppressors that negatively regulate immune responses in the plant model Arabidopsis thaliana. Better understanding of the plant immune system, the scientists say, will allow breeders to create crops with more durable safeguards against pathogens.

The plant immune system works this way: Pathogens deploy effector proteins to mess up with the plant's immune system. These effectors trigger an immune response by activating specific plant resistance proteins. The resistance proteins, in turn, are regulated by suppressors to achieve minimal side effects to the plant while providing optimal responses to pathogens. The suppressors act as guards to prevent the plant immune system from overreacting.

In the study published by the Plant Journal, Walter Gassmann and colleagues examined plants with genetic mutations that resulted in heightened plant immunity. By examining this mutation, researchers were able to identify specific genetic components that may negatively regulate the immune system and thus contribute to an appropriate immune response.

The complete article is available at http://munews.missouri.edu/news-releases/2009/0527-Gassman-plant-defense.php Download the papers published by The Plant Journal and Plant Signaling and Behavior at http://dx.doi.org/10.1111/j.1365-313X.2008.03669.x and http://www.landesbioscience.com/journals/10/article/7682/