Metabolites Mining and Path Enrichment Analysis of Tigernut Tuber Formation

GUO Xiaoyang; LA Guixiao; XU Xinran; YU Yange; DAI Dandan; LI Yanpeng; WANG Yanhong; GUO Hongxia; YANG Tiegang

doi:10.15933/j.cnki.1004-3268.2024.08.004

Abstract：In order to dig out the key metabolites in the process of forming tubers by the stolons of tigernut and regulate the stolons to form more tubers,the stolons and new tubers were taken as the research objects,and untargeted metabolomics analysis was carried out by high performance liquid chromatography combined with triple quadrupole mass spectrometer.And then,the differential metabolites related to the formation of tubers were screened by multivariate statistical method,and KEGG metabolic pathways associated with differential metabolites were enriched.The results showed that a total of 1 217 metabolites were detected in unexpanded stolons(PFJ1),expanded stolons(PFJ2)and new tubers(JD1).According to the conditions of VIP(Variable importance in the projection)>1,P<0.05 and FC(Fold change)>2 or FC<0.5,35 differential metabolites were screened for JD1 vs PFJ1,of which 26 were up-regulated and nine were down-regulated;JD1 vs PFJ2 identified 57 differential metabolites,of which 50 were up-regulated and seven were down-regulated;PFJ2 vs PFJ1 identified 39 differential metabolites,of which three were up-regulated and 36 down-regulated.The metabolites were identified as amino acids and their derivatives,nucleotides and their derivatives,organic oxygen compounds,flavonoids,phenylpropanes,phenols and so on.The relative content analysis of differential metabolites showed that the content of glutathione in JD1 was 14.021 times that in PFJ1 and 29.195 times that in PFJ2.The content of 3-methy-L-histidine in JD1 was 10.463 times that in PFJ1 and 129.931 times that in PFJ2.The content of kaempferol in JD1 was 0.421 times that in PFJ1 and 0.358 times that in PFJ2.KEGG pathway analysis of differentially expressed metabolites was further conducted,and they were mainly concentrated into KEGG pathways such as aminoacyl-tRNA biosynthesis,arginine and proline metabolism,alanine,aspartic acid and glutamate metabolism,phenylalanine metabolism,flavonoid and flavonol biosynthesis.In summary,amino acids and flavonoids were the main metabolites related to the formation of tubers,and the metabolic pathways were mainly concentrated in aminoacyl-tRNA biosynthesis and flavonoid and flavonol biosynthesis.