High temperature and microbiome conditions affect gene expression in soybean

Authors: VAN DER LAAN, LIZA - Iowa State University; ELANGO, DINAKARAN - Iowa State University; FERELA, ANTONELLA - Iowa State University; O`Rourke, Jamie; SINGH, ASHEESH - Iowa State University

Submitted to: bioRxiv
Publication Type: Pre-print Publication
Publication Acceptance Date: 11/4/2024
Publication Date: 11/5/2024
Citation: Van Der Laan, L., Elango, D., Ferela, A., O'Rourke, J.A., Singh, A.K. 2024. High temperature and microbiome conditions affect gene expression in soybean. bioRxiv. Article: 11.04.620947. https://doi.org/10.1101/2024.11.04.620947.
DOI: https://doi.org/10.1101/2024.11.04.620947

Interpretive Summary: In agriculture, heat stress often results in yield loss. Due to global climate change, heat stress events are increasing in frequency and duration. The soil microbiome, microorganisms living in the soil that interact with the plant roots in either a positive or negative manner, may play a role in conferring heat stress tolerance. This study examines whole genome expression data of leaves from four soybean lines differing in heat stress tolerance grown either in soil collected from Iowa fields or autoclaved soils (no microbiome), under normal or high heat conditions for 33 days. Using the gene expression data, we identified genes with conserved expression profiles under high heat common to all four genotypes. These genes may play key roles in the soybean core heat stress response. We also determined gene expression patterns were impacted in plants grown in soils with a soil microbiome, and those changes were temperature dependent with more genes changing under heat stress conditions. This research helps identify genes underlying heat stress tolerance and confirms the importance of a soil microbiome.

Technical Abstract: Heat stress is increasingly a problem in global agriculture production, both in increasing occurrences and extended durations. Understanding the molecular mechanisms of the soybean heat stress response is essential for breeding heat tolerant soybeans. Plant associated microbiomes are known to mitigate adverse effects from abiotic stress. Soybean heat stress studies have primarily focused on response to short periods of stress. How the soil microbiome impacts soybean heat stress responses on a transcriptional level is poorly understood. We hypothesize the soil microbiome may help soybean survive long-term heat stress exposure. We used RNA-seq to measure the transcriptional responses in four soybean lines exposed to two temperature regimes and grown in two soil microbiome conditions. We identified unique responses to temperature based on the soil microbiome conditions and to the different genotypes, with fewer changes across genotypes in response to different soil microbiomes. Our findings provide insights on the interaction of soil microbiomes with heat stress response in soybean and identify gene targets to further study the soybean heat stress tolerance with applications to develop improved varieties.