基于广泛代谢组学的荔枝果肉营养代谢物综合解析

Widely Targeted Metabolomics Analysis of the Nutritional Profile of Litchi Pulp

采用基于超高效液相色谱-电喷雾四极杆飞行时间串联质谱法多反应监测模式的广泛靶向代谢组学对10个荔枝品种的果肉中539种代谢物进行鉴定,描述关于荔枝代谢物组成和丰度的全面信息。结果表明:荔枝果肉初生代谢物298个(55.29%),次生代谢物228个(42.30%);其中氨基酸及其衍生物(82个,15.21%)、脂质(60个,11.13%)、有机酸(59个,10.95%)、核苷酸及其衍生物(53个,9.83%)、糖类及醇类(25个,4.64%)是主要的初生代谢物,黄酮(129个,23.93%)、酚酸类(54个,10.02%)、生物碱(31个,5.75%)是主要的次生代谢物。采用主成分分析和聚类热图分析系统地比较10个荔枝品种的代谢物,发现不同品种间存在明显的分组模式,共聚类为3组且与品种之间的熟期及风味品质相对应。同时关注每类成分中相对含量大于1%的最重要的代谢物,揭示了各类代谢物对荔枝果肉营养的贡献,发现了γ-氨基丁酸、肌醇、石榴酸、葫芦巴碱几种丰度较高且具有特殊功效和营养的代谢物。鉴于荔枝的代谢产物鉴定与人们的营养与健康、果实风味及抗性有着密切的关系,本实验将为鲜食营养、栽培育种、综合利用提供理论依据和参考信息。

A total of 539 metabolites in the flesh of 10 litchi cultivars were identified by widely targeted metabonomics based on an ultra-performance liquid chromatography-quadrupole time of flight-tandem mass spectrometry(UPLC-QTOF-MS/MS)in the multiple reaction monitoring model(MRM),and the comprehensive information about the composition and abundance of metabolites in litchi was described.Totally 298 primary metabolites(55.29%)and 228 secondary metabolites(42.30%)were found.Amino acids and their derivatives(82,15.21%),lipids(60,11.13%),organic acids(59,10.95%),nucleotides and their derivatives(53,9.83%),sugars and alcohols(25,4.64%)were identified as the main primary metabolites,and flavonoids(129,23.93%),phenolic acids(54,10.02%)and alkaloids(31,5.75%)were identified as the main secondary metabolites.Principal component analysis(PCA)and cluster heat map analysis were used to compare the metabolites of the 10 litchi cultivars.It was found that these cultivars were clearly separated into three distinct clusters according to the time of maturation and the flavor quality of the cultivars.The most important metabolies with relative content of more than 1%in each class were identified,and the contribution of each class of metabolites to the nutrition of litchi pulp was revealed.In addition,γ-aminobutyric acid,inositol,garnet acid and trigonelline were found to be abundant metabolites with unqiue functional and nutritional properties.In view of the fact that the identification of litchi metabolites can be closely related to people’s nutrition and health,as well as fruit flavor and resistance,the results of this study will provide a theoretical basis and reference information for understanding the nutrition of litchi and its cultivation,breeding,and comprehensive utilization.