Collaborative Research: Understanding Molecular Mechanisms of Immune Response to a Herbivore-Associated Peptide Elicitor

University Of Washington, Seattle WA

Investigators

Abstract

Plants are defended from pests and pathogens through a sophisticated immune system to recognize attackers. The molecular pathways which control immune responses to chewing herbivores such as caterpillars are poorly understood. Detection of insect attackers is mediated by receptors at the plant cell plasma membrane which bind characteristic molecular patterns of attack and send intracellular signals to active defense responses. How these receptors carry out recognition and signaling functions is of critical importance for disease and pest resistance including in crop plants. This proposal seeks to define pathways and molecular factors which control plant responses to herbivores within an attacked plant leaf. Understanding these factors will allow targeted breeding and/or engineering of resistance traits against herbivores. The project will also launch an innovative cross-campus internship to solidify undergraduate identity as a plant biologist. Two undergraduates each summer will participate in the alternative campus’ Louis Stokes Alliance for Minority Participation (LSAMP) internship at University of Washington or UC Davis in a mentored research experience, before returning to their home campus for their senior year. Participation for each student in two plant immunity labs will strengthen confidence and feeling of self-efficacy in promising BIPOC or first-gen interns. The project will leverage Inceptin Receptor (INR), a newly discovered pattern recognition receptor (PRR) which detects Inceptin, a herbivore-associated molecular pattern (HAMP) found in caterpillar oral secretions. INR is a leucine-rich repeat-containing, receptor-like protein and is specific to a subtribe of legumes, the Phaseolinae. The project will use backcrossed lines of common bean with an introgressed INR deletion to quantify the contribution of INR to overall herbivore defense. Receptor-dependent responses following live herbivore challenge will be quantified at multiple timepoints and spatial scales. Reverse genetic approaches will be used to test the contribution of putative herbivore-specific factors. A forward genetic screen for novel legume factors will also be performed. The project will test the hypothesis that INR-mediated responses to HAMPs reflect amplification of damage-associated processes as well as specific targets for strong anti-herbivore defense responses. The proposed work will span plant-pathogen and plant-herbivore interactions to contribute to a holistic view of PRRs functions in plant biotic interactions. INR is a candidate for transfer into legume and non-legume species that lack this specific PRR, including soybean. Understanding the immune contribution of a HAMP recognition module will inform the use of PRRs to confer agricultural traits. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.