Fiskeby III and Mandarin(Ottawa) soybean RNA-seq response to iron deficiency stress

Fiskeby III has a high level of resistance to a multitude of abiotic stresses, including iron deficiency. In addition, Fiskeby III incurs only mild yield loss during stress conditions, in comparison to other soybean lines. These characteristics have made it a valuable addition to the northern soybean breeding programs in the US and Canada. Conversely, Mandarin(Ottawa) is highly susceptible to disease and suffers severe phenotypic damage and yield loss when exposed to abiotic stresses such as iron deficiency, a major challenge to soybean production in the northern Midwestern United States. Using RNA-seq, we characterize the transcriptional response to iron deficiency in both Fiskeby III and Mandarin(Ottawa) to better understand abiotic stress tolerance. Previous work by our group identified a quantitative trait loci (QTL) region on chromosome 5 associated with Fiskeby III iron efficiency (Merry et al. 2019). This indicates that Fiskeby III may utilize iron deficiency stress mechanisms not previously characterized in soybean. Coupling virus induced gene silencing with RNA-seq, we identified a single high priority candidate gene that has a significant impact on iron deficiency response pathways. Characterization of the Fiskeby III responses to iron stress and the genes underlying the chromosome 5 QTL provides novel targets for improved abiotic stress tolerance in soybean.