|CHEBROLU, KRANTHI - University Of Missouri|
|FRITSCHI, FELIX - University Of Missouri|
|YE, SONGQING - University Of Missouri|
|Smith, James - Rusty|
Submitted to: Metabolomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2015
Publication Date: 2/1/2016
Publication URL: http://handle.nal.usda.gov/10113/61846
Citation: Chebrolu, K., Fritschi, F., Ye, S., Krishnan, H.B., Smith, J.R., Gillman, J.D. 2016. Impact of heat stress during seed development on soybean seed metabolome. Metabolomics. 12(2):28.
Interpretive Summary: Soybean is primarily grown for the high value protein and oil present in the seed. The physiological processes that lead to seed oil and protein are impaired by increased temperature. The MidSouth region of the United States suffers from endemic late season water shortage, and a successful strategy to avoid drought, the early soybean production system, has increased on-farm return by planting and harvesting earlier. However, this also increased the occurrence of high heat during seed development, which has decreased seed quality and dramatically impaired germination for elite cultivars grown using this yield boosting method. Previous studies identified a soybean germplasm accession which resists high heat, resulting in near-perfect germination and seed quality. We utilized global chemical analysis to quantify a large number of seed compounds. A diverse set of anti-oxidant compounds are much enriched in seeds of the heat-resistant line, which translates to a greater ability to deal with oxidative damage. These results will impact breeding strategies and cultivar usage as climate change increases the occurrence and frequency of drought and high summer heat.
Technical Abstract: Seed development is a temperature-sensitive process that is much more vulnerable than vegetative tissues to abiotic stresses. Climate change is expected to increase the incidence and severity of summer heatwaves, and the impact of heat stress on seed development is expected to become more widespread during the course of the 21st century. A recent change to soybean cultivation practices in the Midsouthern region of the United States is also associated with higher temperatures during seed development, which frequently results in seed with poor germination, increased incidence of pathogen infection, and decreased economic value. Global metabolite profiles were contrasted between seed from heat-tolerant and heat-susceptible genotypes produced under control and two elevated temperature conditions. Seed of a heat-tolerant line were able to germinate with much high efficiency, and in general were less impacted by elevated temperatures as compared to a commonly grown high yielding, but heat-sensitive genotype. A total of 275 seed metabolites were analyzed by three metabolite profiling methods, and genotype-specific differences and temperature specific differences were identified. A diverse set of antioxidant metabolites were found to be enriched in seed of the heat tolerant genotype; these compounds are likely responsible, at least in part, for the physiology of heat tolerance.