Metabolomics Analysis Of Opisthopappus Shih Leaves And Flowers

The Opisthopappus Shih,including O.taihangensis and O.longilobus,mainly grows in the Taihang Mountains.Compared with other Asteraceae species,it can release a type of distinctive fragrance.In this study,based on LS-MS/MS untargeted metabolomics technology,we identified and analyzed the categories and quantities of metabolites originated from leaves and flowers of Opisthopappus which gowns in different environmental conditions corresponding to wild,indoor cultivation and interactive plantation cultivation,respectively.For investigating the metabolic mechanism of the Opisthopappus responding to the changing environment,the up-regulated and down-regulated metabolites were detected and the KEGG enrichment analysis were conducted between these different metabolites.For metabolites of leaves,21356 features were detected in positive ion mode and15,488 features were obtained in negative ion mode.The results of KEGG annotation analysis showed that the most features were metabolic components both in positive(3482,96.6%)and negative(2051,96.4%)ion mode,respectively.9830 and 7651 high-quality metabolites occurred in the positive and negative ion mode via quantitative analysis.In wild group(TH/CL),693 up-regulated and 714 down-regulated metabolites were detected,while in cultivated group(TH-H/CL-H)there were 771 different metabolites including 428up-regulated and 343 down-regulated metabolites.Moreover,999 and 732 metabolites between wild O.taihangensis and indoor cultivated O.taihangensis(TH/TH-H)were up-regulated and down-regulated.The differential metabolites between wild O.longilobus relative to indoor cultivation O.longilobus(CL/CL-H)contained 109 up-regulated and 138down-regulated metabolites.KEGG enrichment analysis indicated that the TH/CL group,TH-H/CL-H group,TH/TH-H group and CL/CL-H group enriched in 73,47,87 and 59 metabolic pathways,respectively.In TH/CL,there were significant differences in Arachidonic acid metabolism,Limonene and pinene degradation,Indole alkaloid biosynthesis,and Carotenoid biosynthesis pathways.In TH-H/CL-H,there were significant differences in Nicotinate and nicotinamide metabolism and Tryptophan metabolism pathways.These results indicated that the up-regulated metabolites enhanced the anti-oxidation capabilityand drought resistance of leaves,and the different metabolic pathways might be regarded as the consequence of the adaption of the two species responding to the change of habitats.Subsequently,the shared significantly different metabolic pathways in TH/CL and TH-H/CL-H,were flavonoid biosynthesis: Isoflavonoid biosynthesis,Flavonoid biosynthesis,Flavone and flavonol biosynthesis.Significantly different metabolic pathways in CL/CL-H and TH /TH-H mainly focused on terpenoid metabolic pathways including Monoterpenoid biosynthesis,Sesquiterpenoid and triterpenoid biosynthesis,and Ascorbate and aldarate metabolism pathways.Thus,flavonoids,terpenoids and ascorbic acid might be the main metabolites that affected the growth and adaptation of leaves.The differential metabolites shared by terpenoids,such as 1,8-cineole,myrcene,and(-)-?-pinene were the main substances in the development process of leaves.For metabolites in flowers,15797 features were detected in positive ion modeand10,804 features were detected in negative ion mode.Similar to the leaves,the metabolic components were the most terms in the KEGG annotation analysis.In the positive and negative ion mode,a total of 5439 features were obtained,accounting for 97.6%.By quantitative analysis,14262 and 10004 high-quality substances were obtained in the positive and negative ion mode,respectively.The differential metabolites of wild O.taihangensis relative to O.longilobus(TH/CLW)were up-regulated 4020 and down-regulated 3722;the differential metabolites of wild O.taihangensis relative to interactive plantation cultivated O.longilobus group(TH/CLT)were up-regulated 2560 and down-regulated 3135;the differential metabolites of wild O.longilobus relative to interactive plantation cultivated O.longilobus group(CLW/CLT)were up-regulated 919 and down-regulated 1189.Differential metabolite KEGG enrichment analysis showed that the TH/CLW group was enriched in 59 metabolic pathways,TH/CLT was enriched in 61 metabolic pathways,and CLW/CLT was enriched in47 metabolic pathways.In TH/CLT,there were significant differences in ABC transporters and Glycosylphosphatidylinositol(GPI)-anchor biosynthesis pathways;it showed that the differential metabolites played important roles in the growth and development of flowers,and the differential metabolic pathways might be the responses of the genus to the habitat changes.Phenylpropanoid biosynthesis and Arginine biosynthesis were the shared differential metabolic pathways in TH/CLT,TH/CLW and CLW/CLT.While for TH/CLT and TH/CLW,the same significantly different metabolic pathways included Biosynthesis of amino acids,Purine metabolism,Flavone and flavonol biosynthesis,Aminoacyl-t RNA biosynthesis,Alanine,aspartate and glutamate metabolism.These results indicated that phenylpropanes,amino acids and flavonoids might be the main metabolites that affected the growth and adaptation of flowers.Therein,the common differential metabolites of phenylpropanes,such as carvacrol,thymol,eugenol and cinnamaldehyde,were the main substances in the developing process of flower.In conclusion,O.taihangensis and O.longilobus could respond to different environmental conditions by regulating the metabolite synthesis pathway to produce up-regulated or down-regulated metabolites to enhance the adaption capabilities in the face of changing environments.