基于非靶向代谢组学对青花菜花球表面蜡粉代谢物的差异分析

Differential Analysis of Metabolites in Wax Powder on Surface of Broccoli Florets Based on Non-targeted Metabolomics

为了揭示青花菜花球表面蜡粉代谢物的成分差异,以青花菜蜡粉缺失突变体和野生型为试材,基于气相色谱-质谱(gas chromatography tandem time-of-flight mass spectrometry,GC-TOF-MS)联用技术的非靶向代谢组学,对青花菜蜡粉缺失突变体和野生型的花球主要代谢通路及其产物进行深入分析,并采用单变量和多元变量统计分析及数据库注释筛选差异显著的代谢物。结果表明,青花菜花蕾蜡粉中共检测出显著差异代谢物24种,包括14种氨基酸类、4种有机酸类、1种脂肪酸类、1种胺类、1种糖类和3种其他类次生代谢物;其中,下调的有18种,包括了13种氨基酸类。综合富集分析和拓扑分析获得11条重要性凸显的代谢通路,其中差异最显著的代谢通路是氨基酸的生物合成,其次是次生代谢物的生物合成;而重要性最大的是色氨酸代谢。推测青花菜蜡粉缺失可以通过调节色氨酸代谢、次生代谢物生物合成以及氨基酸生物合成等途径,调节青花菜花蕾中氨基酸类和有机酸类等次生代谢产物的物质含量,进而调控花球的生长、营养品质以及耐寒性。

In order to reveal the composition difference of the wax powder metabolites on the surface of the broccoli inflorescence,taking the wax powder deficient mutant and the wild type of broccoli as test materials,based on the non-targeted metabolomics of gas chromatography tandem time-of-flight mass spectrometry(GC-TOF-MS),the main metabolic pathways and their products of the broccoli wax powder deficient mutant and the wild type were deeply analyzed,and the significantly different metabolites were screened by using univariate and multivariate variable statistical analysis and database annotation.The results showed that a total of 24 significantly different metabolites were detected in the wax powder of broccoli buds,including 14 kinds of amino acids,4 kinds of organic acids,1 kind of fatty acid,1 kind of amine,1 kind of sugar,and 3 kinds of other secondary metabolites.Among them,there were 18 kinds of down-regulated,including 13 kinds of amino acids.Through comprehensive enrichment analysis and topological analysis,11 important metabolic pathways with prominent significance were obtained,among which the most significantly different metabolic pathway was the biosynthesis of amino acids,followed by the biosynthesis of secondary metabolites;and the most important one was tryptophan metabolism.Therefore,it is speculated that the lack of broccoli wax powder can regulate the content such as amino acids and organic acids and other secondary metabolites in the broccoli buds by regulating the pathways such as tryptophan metabolism,the biosynthesis of secondary metabolites,and the biosynthesis of amino acids,then regulate the growth of the inflorescence,the nutritional quality,and the cold resistance.