3个不同木薯品种的代谢产物解析

Analysis of Metabolites of Three Different Cassava Varieties

本研究以3种木薯品种(‘KU50’‘SC205’和‘SC9’)块根为实验材料,采用色谱-质谱联用非靶向代谢组学技术,对8月龄木薯块茎的代谢物进行差异性分析。通过鉴定共获得77个差异代谢物,主要涉及糖及其衍生物、氨基酸、有机酸等,‘KU50’和‘SC205’两个品种的优势代谢产物(相对含量>15%)均为蔗糖,且二者含量基本相当,‘SC9’的优势代谢产物为蔗糖与果糖;‘SC9’中蔗糖、柠檬酸相对含量显著低于‘KU50’和‘SC205’,但果糖、半乳糖、葡萄糖高于二者。利用主成分分析(PCA)发现,3个木薯品种块根代谢物组成结构差异性显著,获得差异显著的33种代谢物中主要涉及糖类及其衍生物、有机酸及其衍生物、生物碱、核苷酸及其衍生物、氨基酸及其衍生物等5个类别。通过GO、KEGG、通路富集分析共注释到14个差异显著性代谢途径,其中,共有16个代谢物富集于氨酰tRNA生物合成途径,9个富集于精氨酸和脯氨酸代谢途径,3个富集于氰基氨基酸代谢途径。本研究通过对3个木薯品种块根代谢物的种类、相对含量、主要代谢物和显著差异代谢物进行分析,阐明了不同木薯品种淀粉品质形成的物质基础。可为后期更好地进行木薯品种改良、品种选育及木薯食品加工提供参考。

In this study,the root tubers of three cassava varieties(‘KU50’‘SC205’and‘SC9’)were used as the experi-mental materials.The metabolites of 8-month-old cassava tubers were analyzed by chromatography-mass spectrometry with non targeted metabolomics.A total of 77 differential metabolites were obtained through identification,mainly in-volving sugar and its derivatives,amino acids,organic acids,etc..The dominant metabolites(relative content>15%)of‘KU50’and‘SC205’were sucrose,and the contents were basically the same.The dominant metabolites for‘SC9’were sucrose and fructose.The relative contents of sucrose and citric acid in‘SC9’were significantly lower than those of‘KU50’and‘SC205’,but the contents of fructose,galactose and glucose were higher than those of‘KU50’and‘SC205’.Principal component analysis(PCA)found that there were significant differences in the composition and structure of root metabolites among the three cassava varieties.Among the 33 metabolites,there were mainly five categories,in-cluding sugars and the derivatives,organic acids and the derivatives,alkaloids,nucleotides and the derivatives,amino acids and the derivatives.A total of 14 metabolic pathways with significant differences were annotated through GO,KEGG and pathway enrichment analysis,of which 16 metabolites were enriched in aminoacyl tRNA biosynthesis pathway, nine in arginine and proline metabolism pathway and three in cyano amino acid metabolism pathway. By ana-lyzing the types, relative contents, main metabolites and significantly different metabolites of root tubers of the varieties, this paper would enrich the material basis of starch quality formation of different cassava varieties and provide a refer-ence for cassava variety improvement, variety breeding and cassava food processing in the later stage.