Plant and animal cells sense and respond to signals in their environment through receptors that relay biochemical information via protein-protein interactions to the nucleus, where changes in gene expression occur. One class of these receptors (the Leucine-Rich Repeat Receptor-like kinases or LRR RLKs) is present in a large family of 223 members in the model plant Arabidopsis thaliana. These receptors have a structural organization similar to that of animal receptor kinases, and several that have been studied in detail are known to be critical elements that regulate the plant's growth, morphogenesis, disease resistance, and responses to stress. However, the functions of the vast majority of this large family of signal transduction molecules remain unknown. With previous support from the NSF Arabidopsis 2010 Program, the investigators have generated a set of genetic and biochemical resources that will allow the in-depth study of the function of LRR RLKs in plant growth and stress responses. Using proteomic and mass spectrometry approaches, this project is designed to define the proteins that interact with these LRR RLKs. These proteins form an interactive network whose function ultimately determines a range of physiological responses, and this project will define the components and properties of this network. In addition to this broad study of protein network interactions, a selected group of LRR-RLKs will be characterized at a detailed biochemical level, including functional analyses that will permit an understanding of how these proteins influence plant growth.
Broader Impact of the Research: Given the known importance of the LRR RLK family to plant development, the results of this project are likely to have practical agricultural impact. In addition this project will provide extensive resources to the Arabidopsis research community including a database (http://www4.ncsu.edu/~sclouse/Clouse2010.htm) that creates a unique resource for the comparative study of LRR RLK protein networks and phosphorylation sites. The highly successful NSF-supported Plant Phosphorylation Workshop will be reinitiated and will serve as a forum for researchers from as many as 45 laboratories to interact and share research ideas and results. The project will also provide training in protein biochemistry, mass spectrometry, and Arabidopsis molecular genetics at all levels from high school student interns through postdoctoral scientists. Recruitment of these individuals will be integrated with established programs at North Carolina State University and the University of Illinois that encourage the participation of under-represented minorities in scientific research.
