Graduate student North Dakota State University Fargo, North Dakota
Body of Abstract: Iron deficiency chlorosis (IDC) is a significant yield constraint in agriculture, particularly for soybean, a major crop in the United States. While there are some management practices to overcome IDC, none of them are cost-effective or environmentally sustainable. Therefore, our study focuses on restructuring and compositional changes of the microbiome underpinning IDC tolerance in soybean, which will be translated by developing co-inoculants with rhizobia and evaluating the ability of IDC-recruited microbes to combat IDC in soybean. We sampled four soybean genotypes having differential sensitivity or tolerance to IDC from four different field locations in North Dakota having variant degrees of Fe deficiency. Our preliminary data showed a clear restructuring of the soybean microbiome under different IDC levels at four field sites. We further repeated the trial with Fe-chelating Soygreen to reduce IDC at all locations. This will unambiguously identify microbes at high IDC sites specifically recruited by Fe-deficient soybean. This may prioritize the targeted isolation of IDC-recruited microbes and the development of microbial inoculants to test the inoculant potential for solubilizing Fe. We have adopted a high throughput culturomics pipeline to isolate matched amplicon sequence variants to those tracked in microbiome data from fields. Selected microbes are screened in vitro for Fe solubilizing capability (via siderophores or acidification) and formulated with rhizobia, individually or as consortia, and tested for IDC reduction in a greenhouse assay previously optimized to test IDC in soybeans. Taken together, this novel and transformative approach would encourage studies on the microbiome for improving crop health and productivity.