Exploring the Impact of Extended Heat Stress and the Soil Microbiome on Gene Expression in Soybean

The goal is to asses the transcriptional changes in soybean leaf tissue due to a factorial combination of long-term heat stress and soil microbiome. Soybeans were planted in soil with or without a microbiome, and then underwent continuous heat stress for a prolonged period of time.Heat stress is increasingly a problem in global agriculture production, both in occurrences and durations. Understanding the molecular mechanisms of 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 soybean responds on a transcriptional level to a soil microbiome is poorly understood. We hypothesize a soil microbiome may help soybean survive long-term heat stress exposure. We used RNA-seq to measure the transcriptional responses in four soybean genotypes exposed to two temperature regimes and grown in two soil microbiome conditions. We identified unique responses to temperature based on the genotype and the soil microbiome conditions. We additionally found unique transcriptional responses due to the soil microbiome, and that this varied due to genotype and temperature. Our findings provide insights on the interaction of soil microbiome with heat stress response in soybean and identify gene targets to further study the soybean heat stress tolerance with applications to develop improved varieties.