Metabolomics-based Exploration the Response Mechanisms of Saussurea involucrata Leaves Under Different Levels of Cold Stress

Abstract

Abstract Saussurea involucrata (Sik.) have high cold resistance and important medicinal value. However, the metabolomics under low temperature conditions is still not fully explained. Understanding the changes of metabolites under low temperature conditions is conducive to in-depth research and rational development and utilization. Methods: Ultra-performance liquid chromatography and tandem mass spectrometry were used to analyze the metabolites in the leaves of Sik. under four different low temperature stress conditions. Results: A total of 753 metabolites were identified, and 360 different metabolites were identified according to the Kyoto Encyclopedia of Genes and Genomes (KEGG) involved in the biosynthesis of secondary metabolites and amino acids and sugars. Sucrose and trehalose synthesis, glycolysis, tricarboxylic acid cycle, pentose phosphate pathway, glutamic acid-mediated proline biosynthesis, purine metabolism, amino acid metabolism, phenylpropane synthesis pathway metabolites all respond to low temperature stress. Under cold stress conditions, carbohydrates in Sik. leaves accumulate first than under freezing conditions, and the lower the temperature under freezing conditions, the less amino acids accumulate, while the phenolic substances increase. However, after cold domestication, purines and phenolic substances decrease under freezing conditions, and amino acids accumulate significantly. Conclusion: The metabolic network of Sik. leaves under different low temperature stress conditions was proposed, which provided a reference for further exploration of the metabolic network related to low temperature stress tolerance of Sik.