Trilateral FPP 2023: Climate-resilient Crops with Improved Phosphorus Efficiency through Beneficial Fungal Interactions

Pennsylvania State Univ University Park, University Park PA

Investigators

Abstract

Modern crop production is sustained by the application of phosphorus fertilizers. The ultimate source of this phosphorus is non-renewable deposits of high-grade phosphate rock. The logistic costs of extracting and transporting a bulky commodity, along with unpredictable fluctuations of the global market, have seen fertilizer prices rise over recent years, with unanticipated spikes placing strain on already tight farm budgets. And yet, although great effort and resources are invested to deliver phosphorus to farmer’s fields, only a small percentage of what is applied is acquired by the plants. Much of the phosphorus is washed out to end up in water courses and, ultimately, the ocean, contributing to the well-documented environmental problem of algal blooms. In wild ecosystems, most plant species acquire phosphorus from the soil at high efficiency through association with symbiotic soil fungi. Staple crop species retain the capacity to form such fungal associations, but the system is far from optimized for agricultural conditions. This project will build on the latest molecular and genetic understanding of the mechanisms regulating cereal interactions with beneficial soil fungi. Specifically, the project will employ natural plant genetic variants to boost the level of interaction with soil fungi in corn and rice and evaluate the impact on plant performance under both standard and low phosphorus field conditions. Additional molecular studies will characterize the nature of the fungal communities in cultivated fields and assess the capacity of novel plant varieties to better work with soil fungi towards more efficient uptake and use of phosphorus fertilizers. This project develops new biotechnology critical to the future security of key crops, e.g., rice and corn. This project aims to evaluate and enhance arbuscular mycorrhizal symbiosis in rice and maize for greater nutrient efficiency. Although modern cereals retain the molecular machinery necessary for formation of mycorrhizal associations, the symbiosis, which dates back 450 million years, is not optimized to the high-input agroecosystems developed over the last century of agricultural intensification. Specifically, crops, as all plants, will reject the fungus under high-nutrient conditions. Selection and breeding in such environments have generated varieties that are not best placed to take full advantage of arbuscular mycorrhizal symbiosis. In this project, plant mutants with modulated sensing of internal phosphorus status will be evaluated for their capacity to sustain arbuscular mycorrhizal symbiosis under high phosphorus conditions. Material will be characterized in the field, with novel sequencing-based approaches used to characterize soil mycorrhizal and broader microbial communities in parallel with plant molecular, physiological and agronomic evaluation. In the context of a tri-national collaboration with partners in the U.K. and Germany, this work will contribute to fundamental understanding of crop nutrient signaling and mutualistic microbial associations in parallel with field-testing high-colonization host plants as a basis for breeding towards great nutrient efficiency through enhanced arbuscular mycorrhizal symbiosis. This award was funded as part of a lead agency opportunity between NSF, UKRI-BBSRC (UK Research and Innovation - Biotechnology and Biological Sciences Research Council; Lead) and DFG (Deutsche Forschungsgemeinschaft/German Research Foundation) where NSF funds the U.S. investigator, UKRI-BBSRC funds the U.K. partner and DFG funds the German partner. 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.