Investigating the role of known Arabidopsis iron genes in a stress resilient soybean line

Authors: O'Rourke, Jamie; Graham, Michelle

Submitted to: International Journal of Molecular Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/22/2024
Publication Date: 10/25/2024
Citation: O'Rourke, J.A., Graham, M.A. 2024. Investigating the role of known Arabidopsis iron genes in a stress resilient soybean line. International Journal of Molecular Sciences. 25(21). Article 11480. https://doi.org/10.3390/ijms252111480.
DOI: https://doi.org/10.3390/ijms252111480

Interpretive Summary: Genes involved in iron deficiency responses have been well characterized in model plant species, but their roles in crop species have not been well explored. While similar sequences are activated during iron stress responses in soybean, their impact has yet to be determined. Further, our reliance on information gained from model species may hinder our ability to identify novel iron stress mechanisms present within diverse crop species. Fiskeby III (PI 438471) is a soybean line from Sweden that demonstrates high levels of resiliency to numerous stresses. Earlier Fiskeby III studies have identified a suite of genes responding to iron deficiency stress in Fiskeby III that are also associated with iron deficiency responses identified from model species. Given iron deficiency tolerance in Fiskeby III has been mapped to a novel quantitative trait loci (QTL) on chromosome GmChr05, we were interested in determining how these iron genes function in Fiskeby III under normal and iron stress conditions. To investigate this, we have used virus induced gene silencing to knock down gene expression of three iron deficiency response genes (FIT, HY5 and PYE) in Fiskeby III. Analyses of whole genome expression data generated from silenced plants in iron sufficient and deficient conditions found silencing FIT and HY5 altered general stress responses but did not impact iron deficiency tolerance, confirming Fiskeby III utilizes novel mechanisms to tolerate iron deficiency stress.

Technical Abstract: Genes involved in iron deficiency responses have been well characterized in Arabidopsis thaliana, but their roles in crop species have not been well explored. Homologs of canonical iron genes identified in RNAseq studies of crop plants provide supporting evidence for a role in iron deficiency stress responses. However, reliance on model species may fail to identify novel iron stress mechanisms present within crop species, likely selected by hundreds of years of selection. Fiskeby III (PI 438471) is a soybean line from Sweden that demonstrates high levels of resiliency to numerous stresses. Earlier Fiskeby III studies have identified a suite of genes responding to iron deficiency stress in Fiskeby III that are also associated with Arabidopsis iron deficiency responses. Given iron deficiency tolerance in Fiskeby III has been mapped to a novel quantitative trait loci (QTL) on chromosome GmChr05, we were interested in determining how these iron genes function in Fiskeby III under normal and iron stress conditions. To investigate this, we have used virus induced gene silencing to knock down gene expression of three iron deficiency response genes (FIT, HY5 and PYE) in Fiskeby III. Analyses of RNAseq data generated from silenced plants in iron sufficient and deficient conditions found silencing FIT and HY5 altered general stress responses but did not impact iron deficiency tolerance, confirming Fiskeby III utilizes novel mechanisms to tolerate iron deficiency stress.