A protein called RaxX may help create more disease-resistant rice varieties and block microbial infections in both plants and animals.
When disease-resistant rice is invaded by disease-causing bacteria, RaxX is sensed by the rice plants and causes an immune response.
The RaxX protein is present in at least eight species of the disease-causing Xanthamonas bacteria that attack rice, a staple crop for half of the world's population.
The study shows that RaxX closely resembles a class of plant signaling factors that promote growth and modulate the immune response. They suspect that the bacteria could be mimicking these natural plant-signaling factors to inhibit the plant immune response and thereby enhance the competitiveness of the bacteria. In the long term, the researchers hope to use this information to develop new strategies to prevent infection in various crops.
"Our research team is delighted to announce the discovery of the RaxX protein, a new class of microbial signaling molecules ," said Pamela Ronald, a professor in UC Davis' Department of Plant Pathology and Genome Center, who directed the study.