EAGER: The Involvement of Blue Light in Plant Immunity

University Of Nebraska-Lincoln, Lincoln NE

Investigators

Abstract

Plants are dependent on light for their survival and can perceive different colors of light with various sensors. Phototropins are blue light sensors that trigger a variety of plant responses that poise the plant for efficient photosynthesis. At daybreak plants are particularly susceptible to microbial pathogens so it would be logical for plants to evolve the use of light sensors to cue the immune system of the potential threat of a new day. The investigators have compelling data that suggest phototropins are components of the plant immune system. These data concern a protein from a plant pathogenic bacterium which the pathogen injects into plant cells to facilitate infection. The data suggest that the injected protein blocks phototropin function and thereby inhibits immune responses and promotes infection. This project will determine the extent to which phototropins contribute to plant immunity. The investigators will determine the molecular consequence of the interaction of phototropins with the injected bacterial protein and will determine whether blue light, through its influence on phototropins, has an effect on plant immunity. The investigators will determine where phototropins localize in the plant cell after plants are treated with pathogens or inducers of plant immunity. The experiments of this project will offer broad and comprehensive training for students and postdoctoral associates. The PI is involved in educational programs that will provide high school students and undergraduates research and training experiences in plant pathology and plant immunity at the University of Nebraska. The findings of this project may lead to the development of crops with improved tolerance to biotic stress. Phototropins are blue light receptor kinases that trigger a variety of plant responses that poise the plant for efficient photosynthesis which is critical for the success of the plant. In Arabidopsis there are two phototropins, phototropin 1 (Phot1) and phototropin 2 (Phot2). These receptors control several responses that ensure that plants are poised to carry-out photosynthesis. The investigators have compelling preliminary data that suggest that phototropins also act as components of plant immunity. They will determine the extent that phototropins affect the plant immune system. The specific objectives of the project are: (1) Determine the molecular consequence of the interaction of phot1/2 with the Pseudomonas syringae effector HopK1; (2) Determine the extent that blue light affects plant immunity; (3) Investigate dynamic cellular localization of phototropins after biotic stress.