Metabolomics Reveals The Drought-tolerance Mechanism In Glycine Soja

Drought stress is the main limiting factor of crop productivity.In recent years,with the change of natural environment,the area of drought is increasing,which seriously restricts the development of agriculture.Wild soybean(Glycine soja)is a fine germplasm resource,which has a high tolerance to adverse environmental conditions.However,wild soybean is one of the crops with high water demand,and water will directly affect the growth and development of wild soybean seedlings,and then affect their yield and quality.Therefore,it is important for studying the drought-tolerance mechanisms of drought-tolerant wild soybean based on metabolomics.In this study,the two wild soybean varieties(common and drought-tolerant)seedlings were treated with drought stress by polyethylene glycol-6000-simulated drought stress experiment,and the stress treatment period was 14 days.The growth parameters and metabolomics of two wild soybean varieties control and drought stress treatment groups were analyzed.Based on gas chromatography-mass spectrometry,the differences of metabolomics response of two wild soybean varieties’ seedlings leaves to drought stress were analyzed,and the mechanism of drought-tolerant wild soybean to resist drought stress was revealed.A metabolite profiling analysis suggested that the leaves of drought-tolerant wild soybean had significantly higher levels of sugar alcohols and amino acids than those of common wild soybean under simulated drought stress,compared with the control group,including mannitol,sorbitol,glycine,proline,phenylalanine,beta-alanine and methionine.The tricarboxylic acid cycle was enhanced in drought-tolerant wild soybean but inhibited in common wild soybean compared with the control group under simulated drought stress.Compared with common wild soybean,drought-tolerant wild soybean accumulated more secondary antioxidants,including ferulic acid,salicylic acid,4-hydroxy cinnamic acid and 5-methoxytryptamine.The conclusions were as follows:(1)Under drought stress,the growth of two wild soybean varieties seedlings was inhibited,especially that of common wild soybean.(2)Drought-tolerant wild soybean accumulated high levels of osmotic regulators by enhancing amino acid metabolism,glycol metabolism,organic acid metabolism,fatty acid metabolism to resist drought stress,including soluble sugar,proline,glycine,organic acids and fatty acids.(3)Drought-tolerant wild soybean produced a large amount of energy to resist drought stress by enhancing energy metabolism,such as the tricarboxylic acid cycle.(4)Drought-tolerant wild soybean improved their ability to resist drought stress by enhancing phenolic metabolism in secondary antioxidant metabolism.The study provides scientific basis for broadening the genetic basis of soybean and developing and utilizing wild soybean germplasm resources.It provides new ideas and methods for improving the drought resistance of soybean and other crops.At the same time,it also lays the theoretical foundation for the sustainable development of agriculture.