Application Of LC-MS Metabolomics Techniques To The Taxonomy Of Paeoniaceae

The family Paeoniaceae is a single genus.Tree Peonies and peonies are both plants belonging to the Paeonia in the family Paeoniaceae,which is dominated by shrubs,subshrubs and herbaceous plants.Plants of the Paeoniaceae family are widely distributed in the northern hemisphere and have great ornamental as well as medicinal value.Tree peony is the only one that originated in China,while peony is widely distributed worldwide.There are abundant native germplasm resources of tree peony and peony distributed in China.Currently,although the basic classification of Paeoniaceae is largely clear,the classification under its group,evolutionary differences in Paeoniaceae,and the precise place of origin remain uncertain and controversial.In this study,we applied LC-MS metabolomics technique to analyze the evolutionary differences of Paeoniaceae from the perspective of metabolites using 26 leaves of wild Paeoniaceae as study materials,aiming to try to make a new exploration of the taxonomic basis of Paeoniaceae.The main results are as follows:1.A species-specific mass spectrometry metabolome database of Paeoniaceae was established.The chemical composition of 26 Paeoniaceae leaf material extracts was analyzed and identified by applying non-targeted metabolomics analysis,and a total of 214 compounds were identified.For the first time,a plant-specific mass spectrometry database containing 1411 signals of Paeoniaceae was established,and 111 known compounds were identified from the targeted analysis.2.In order to accurately analyze the metabolite composition in the leaves of Paeoniaceae,this thesis establishes a qualitative and quantitative approach to broadly targeted metabolomics of Paeoniaceae.Data acquisition was performed by multiple reaction monitoring-information dependent acquisition-enhanced sub ion scanning(MRM-IDA-EPI)mode in QTRAP-MS.The exact parent ion information and retention times of 124 known compounds and 114 unknown compounds were redetermined using the MRM model,and the characteristic ion pairs(Q1-Q3)of each compound were screened and determined.The conditions for the targeted quantification of the compounds were optimized using the FIA automatic optimization method,and finally an extensive targeted metabolomic qualitative quantification method containing 238 compounds was established with good reproducibility and accuracy.3.Analysis of metabolic fractions in 26 wild leaves of Paeoniaceae revealed that 22 differential compounds evolved between the Sect.Moutan and Sect.Paeonia,and 29 differential compounds evolved between the subsect.Vaginatae and the subsect.Delavayanae.Further analysis showed that these differential compounds were closely related to environmental factors(latitude,altitude,average annual precipitation,etc.),In particular,the latitude factor had the greatest effect on the flavonoids with a positive correlation,and also had a significant effect on the content of paeoniflorin among the terpenoids with a negative correlation.4.Three classes of substances,flavonoids,terpenoids and phenolic acids,are the key metabolites responsible for the evolutionary differences between tree peony and peony.It was also found that the metabolomics data fit well with the traditional classification of phenotypic data.