Developing crops that have stable immunity to evolving pathogens in a variable climate

About This Grant

Plants and pathogens interact in complex ways, with the outcome of this interaction being determined by various factors including their genetics, resident microbiome, and, most crucially, the environment. Variability in plant growing environments, including changes in temperature, have been linked to severe local outbreaks for various pathogens. The most effective way to control plant diseases is the use of disease-resistant cultivars. While current breeding programs evaluate disease resistant cultivars for their durability against concurrent pathogen populations, the sensitivity of plant resistance genes to growing temperatures is rarely considered while assessing their durability. The goal of this project is to develop crops with stable immunity that can tackle the simultaneous challenge of evolving pathogen pressure and suboptimal plant growth temperatures. This project led by a team of scientists from the United States, the United Kingdom, and Germany has the potential to develop crop varieties that are tolerant to changing growing temperatures and outcomes from this work has the potential to ensure future food security. This project will also support continued efforts by the team to provide STEM-based research experiences for high school students, and outreach events for the public in Alabama and Virginia. Graduate students and research associates that are a part of this project will be actively involved in these outreach events aimed to raise awareness of how plant growth temperatures impact plant health and disease pressure. Predicting plant disease outcomes in the face of projected suboptimal growing conditions is challenging for multiple reasons. Host responses to multiple simultaneous stresses are simply not additive. Multivariate selection pressures brought about by temperature fluctuations alter ecological, epidemiological, physiological and evolutionary processes in the host as well as pathogen populations and alter their responses due to trade-offs among traits under selection, thereby altering host-pathogen dynamics. The proposed work will utilize field and growth chamber experiments in parallel to understand how pathogen and plant carrying different resistance genes respond to temperature alteration. This project will investigate multi-generation host-pathoadaptation and assess fitness trade-offs that constrain the evolution in both plant and pathogen. The project will make explicit links between physiological and genetic processes in host and pathogen that inform potential candidates for breeding programs to make heat resilient and disease resistant crops. The project will evaluate temperature sensitivity of resistance genes in pepper and tomato in terms of their stability, function and alteration of immune pathways. This study has direct translational relevance for durable management of resistance genes in the context of variable environmental conditions. 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.