Metabolomics Of Magnolia Wufengensis And Magnolia Denudata At Low Temperature

After introducted to North China,the seedlings of Magnolia wufengensis,a rare tree species discovered in Wufeng,Hubei,are often injured by low temperature during natural wintering,but Magnolia denudata,a closely related species,has good adaptability.The purpose of this research is to explore the metabolic characteristics and difference of Magnolia wufengensis and Magnolia denudata in the process of cold stress and cold acclimation,and discover the metabolic disorders in Magnolia wufengensis under low temperature,and provides a metabolic reference for the introduction,domestication and molecular improvement of Magnolia wufengensis in the north.The stem tip tissues of Magnolia wufengensis and Magnolia denudata during cold stress and cold acclimation were detected by gas chromatography-mass spectrometry(GC-MS)and analyzed by the method of metabolomics.The main differential metabolites and metabolic pathways between samples at different stages were calculated and displayed,and the properties and functions of specific metabolites were discussed.The results showed that(1)at room temperature,Magnolia denudata had more abundant basal metabolites than Magnolia wufengensis,and there were 140 kinds of differental metabolites in the two species,39 species had higher content of Magnolia wufengensis and 101 species had higher content in Magnolia denudata.(2)Under cold stress,the metabolism of amino acids and sugar-related metabolites of Magnolia wufengensis were significant,and the metabolism of amino acids in Magnolia denudata was significant,and the trend of carbohydrate metabolism is different between the two species;After cold stress,the difference of total metabolic level between the two species decreased,and there were only 49 differental metabolic species.(3)In the process of cold acclimation,Magnolia wufengensis appeared in three distinct metabolic stages,the metabolic level fluctuated greatly,the carbohydrate metabolism was significant,and it was suspected to be subject to a certain degree of cold injury;While,the cold acclimationg process of Magnolia denudata appeared as two metabolic stages,when above 4? it is mainly based on the metabolism of sugars and amino acids,Carbohydrate metabolism slowed down at 4 C and amino acid metabolism was remarkable,and the adaptability of Magnolia denudate on cold acclimation process was better;Specific biomarkers were screened for both species at different temperatures during cold acclimation.At low temperatures,the two species showed different metabolic strategies.The regulation of amino acid and carbohydrate metabolism of Magnolia wufengensis is an improved way to improve its cold resistance.