Extracellular ATP Signaling in Plant Defense -- a Damaged-self Recognition System

Washington State University, Pullman WA

Investigators

Abstract

Although ATP is generally considered to be the energy currency molecule in the living cell, ATP also acts as a signal for damage recognition in multicellular organisms when it is released into the extracellular space following cellular damage. Recently, extracellular ATP was suggested to come into play in plant defense responses. Understanding molecular mechanisms that control ATP-induced defense signaling will help identify potential molecular targets to engineer disease resistance into crop plants; this development will not only improve the yield and quality of biomass but it will also reduce the need for added chemicals to control plant disease. Thus, the project is poised to bring significant economic, environmental, and social benefits by preventing pollution in the environment and reducing input costs for producers. The project includes the education and training of post-doctoral researchers and students. Moreover, the project will integrate research and education by providing summer research projects to high school students. A strong emphasis will be placed on recruitment and training of underrepresented groups, especially for the high school summer intern and undergraduate student positions. This training will offer students a potentially empowering and educational glimpse into scientific research, and prepare them for future careers in science. In conclusion, the proposed project integrates research and education to achieve beneficial results for education, agriculture and the environment. The energy currency molecule, ATP, is released into the extracellular space following cellular damage, where it acts as a danger signal for damaged-self recognition in multicellular organisms. Very recently, the first plant purinoceptor, P2 Kinase (P2K), was identified, and further suggested the involvement of extracellular ATP in the plant defense responses to wounding or damage from infectious organisms. However, how the signaling pathway connects to the plant defense response after ATP binding to the P2K receptor is unknown. The long-term goal is to develop an in-depth understanding of the molecular mechanisms mediating extracellular ATP signaling during plant defense responses. The immediate objective is to determine how P2K receptor-mediated ATP signaling regulates plant defense responses. The project?s aims are: (1) Elucidation of sensing mechanism of extracellular ATP by the P2K receptor; (2) Identification and functional analysis of molecular components that act downstream of the P2K receptor; (3) Identification and characterization of signaling networks between extracellular ATP and other stress hormone signaling pathways, so as to elucidate the role of extracellular ATP in plant defense response. This research is crucial to understanding how plants survive pathogen and herbivore attacks as well as giving the researchers a unique opportunity to compare animal and plant purinergic signaling systems, in order to define components and responses that are evolutionarily conserved.