Gene expression responses to sequential nutrient deficiency stresses in soybean.

Authors: O`Rourke, Jamie; Graham, Michelle

Submitted to: International Journal of Molecular Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/22/2021
Publication Date: 1/27/2021
Citation: O'Rourke, J.A., Graham, M.A. 2021. Gene expression responses to sequential nutrient deficiency stresses in soybean. International Journal of Molecular Sciences. 22(3). Article 1252. https://doi.org/10.3390/ijms22031252.
DOI: https://doi.org/10.3390/ijms22031252

Interpretive Summary: Plants grown in the field experience many abiotic stresses throughout the growing season. The cumulative effect of these stresses is a loss of yield. To understand the genes and networks underlying stress tolerance, we measured the gene expression in soybean in response to iron deficiency stress followed by exposure to phosphate deficiency stress (sequential stresses) to more closely mimic field grown plant stress exposure. We compared these gene expression profiles to a previous study where plants were exposed to repeated iron or phosphate deficiency stress. These analyses determined that sequential stress induces a unique suite of genes not differentially expressed under repeated stress conditions. These novel genes are usually involved in highly specialized processes, but after sequential stress exposure are utilized in more basic processes. These findings improve our understanding of soybean response to complex nutrient deficiency stress exposure. These findings improve our understanding of the genes and networks underlying plant stress tolerance which can be leveraged by researchers to improve stress tolerance in soybean and other important crop species.

Technical Abstract: Throughout the growing season, crops experience a multitude of short periods of various abiotic stresses. These stress events have long-term impacts on plant performance and yield. It is imperative to improve our understanding of the genes and networks underlying plant stress tolerance to mitigate end of season yield loss. The majority of studies examining transcriptional changes induced by stress focus on single stress events. Few studies have been performed in model or crop species to examine transcriptional responses of plants exposed to repeated or sequential stress exposure, which better reflect field conditions. In this study, we examine the transcriptional profile of soybean plants exposed to iron deficiency stress followed by phosphate deficiency stress (-Fe-Pi). Comparing this response to previous studies, we identified a suite of genes unique to the novel sequential stress exposure (-Fe-Pi) and core genes conserved across repeated stress exposure (-Fe -Pi, -Fe-Fe, -Pi-Pi).