Comparative protein profiling of two soybean genotypes with different stress tolerance reveals major components in drought tolerance

IntroductionDrought stress has gradually become a limiting factor for plant growth. Soybean, a crop with a higher water demand than other plants, is particularly sensitive to water deficits.MethodTo explore the effect of drought stress on soybean protein expression, we used drought-tolerant soybean genotype HeiNong44 (HN44) and sensitive soybean genotype HeiNong65 (HN65) as experimental materials, PEG-6000 as an osmotic regulator, and tandem mass tag (TMT) technology to identify the differential expression of soybean proteins.ResultsWe identified that 48 upregulated and 38 downregulated proteins in HN44 and 55 upregulated and 13 downregulated proteins in HN65.DiscussionKEGG analysis showed that these differentially expressed proteins were involved in carbohydrate metabolism, signal transduction, amino acid metabolism, lipid metabolism, and programmed cell death. Drought stress usually caused an increase in the activity of plant antioxidant enzymes, the obstruction of photosynthetic synthesis, and a significant change in the content of plant hormones. We found that HN44 responds to drought stress mainly through sugar decomposition, increased antioxidant enzyme activity and lipid metabolism. HN65 responds to drought stress mainly through ABA synthesis, increased antioxidant enzyme activity and amino acid metabolism. Our study also found that differential proteins in the starch and sucrose metabolic pathway play a key role in supplying energy and regulating osmotic potential.