Project Number: 8072-12000-014-004-T
Project Type: Trust Fund Cooperative Agreement
Start Date: Oct 1, 2021
End Date: Jun 30, 2025
Advances in modern agricultural technology with a focus on crop yields has coincided with soil degradation and a decline in crop nutrient quality. This project seeks to better understand the relationship between agricultural practices, soil microbiology, and crop nutrient quality, especially protein, amino acids, and the nutraceutical ergothioneine (ERG) to strengthen the link between soil health and human health. Assessments of plant available nitrogen, ERG, and microbiomes in soil during critical plant growth stages will be paired with leaf tissue and grain nutrient measurements. Sampling will occur in long-term agricultural trials and on farms across the country over three years to capture spatial and temporal variations. Controlled field and greenhouse experiments will be conducted to elucidate the link between farm practices, soil- and plant-microbial processes, and grain nutrient quality. Active research on ergothioneine is finding that this amino acid has antioxidant properties and increasingly apparent human health benefits. It is only biosynthesized by fungi and fungi-like bacteria, is present in many foods, and plants obtain it through an unknown mechanism where it is transferred up the food chain to animals and humans. Thus, there should be a clear link between soil microbiomes, ergothioneine biosynthesis in the soil, its concentration in plants, and human health. Measurement of grains harvested from the Rodale Institute Farming Systems Trial has revealed a link between reduced tillage and increased ergothioneine concentrations in oat and wheat grain. Project partners hypothesize that soil microbiomes (including AMF) which are shaped by short and long-term agricultural practices such as tillage intensity and fertility inputs are responsible for the differences observed in FST grain. The specific role of AMF in ergothioneine biosynthesis and transport will be evaluated as part of this study. Objective 1: Years 1-4, Months 3-40. Concurrently measure plant available nitrogen, minerals, ERG and microbiomes in soil combined with mineral, protein, amino acids, calories, and ERG concentrations in grains produced in long-term systems trials across the US. Objective 2: Years 1-3, Months 3-36. Concurrently measure plant available nitrogen, minerals, ERG and microbiomes in soil combined with mineral, protein, amino acids, calories, and ERG concentration in ancient, heritage, and modern wheat cultivars on farms across the US. Objective 3. Years 2-4, Months 13-40. Concurrently measure plant available nitrogen, minerals, ERG and microbiomes in soil combined with mineral, protein, amino acids, calories, and ERG concentrations in wheat in a field experiment comparing tillage and no-till and varying levels of nitrogen fertility. Objective 4. Years 1-4, Months 3-40. Conduct controlled laboratory and greenhouse experiments using wheat as a model crop to elucidate the role of arbuscular mycorrhizal fungi (AMF) and specific ERG biosynthesizing microbes for ERG uptake and in planta temporal accumulation.
ARS will support the field studies in Objectives 1-3 by conducting analysis of soil fungi using species-specific qPCR assays developed in-house for quantifying AM fungi and also conducting metagenomic analysis other fungal genera using next generation sequencing of the ribosomal DNA internal transcribed spacer (ITS) region. Metagenomic analysis of the bacterial 16S ribosomal DNA will be conducted by PI Jinjun Kan (Stroud Water Research Center).