目的 基于转录组和代谢组联合挖掘佛手Citrus medica中关键黄酮类物质生物合成关键基因，为进一步探究佛手中黄酮类物质的合成调控机制提供基础。方法 采用Illumina HiSeqTM 4 000高通量测序平台对佛手不同发育时期的果实组织进行转录组测序，借助LC-MS/MS技术，对其黄酮类物质进行表征，通过KEGG数据库和关联分析，充分挖掘佛手黄酮类物质生物合成关键基因。结果 通过代谢组学和转录组学分析共获得21个差异黄酮类物质和25个差异表达基因，均存在明显差异。佛手黄酮类物质生物合成途径中，香橙素-7-O-葡萄糖苷、圣草次苷、柚皮苷、芸香柚皮苷、橙皮素-3-O-葡萄糖苷等随果实的发育逐渐降低，芹菜素-5-O-葡萄糖苷、木犀草素-4-O-葡萄糖苷等物质随果实的发育逐渐升高；在佛手黄酮类物质代谢途径中，成功鉴定到苯丙氨酸解氨酶（phenylalanine ammonialyase，PAL）、4-香豆酸辅酶a连接酶（4-comarate coenzyme a ligase，4CL）、查耳酮合成酶（chalcone synthase，CHS）、查耳酮异构酶（chalcone isomerase，CHI）、黄酮3-羟化酶（flavonol-3-dehydrogenase，F3H）、黄酮3’-羟化酶（flavonol-3’-dehydrogenase，F3’H）、黄酮合酶（flavone synthase，FNS）、花青素合成酶（anthocyanidin synthase，ANS）、糖基转移酶（UDP-glyotransferases，UGTs）等关键酶基因。关键酶基因PAL、4CL、CHS、F3H、FNS等负向调控下游代谢物，CHI、UGTs等正向调控下游代谢物，均与下游代谢物显著相关。结论 揭示了佛手在不同发育阶段黄酮类代谢物和相关基因的差异表达模式，为阐明佛手黄酮类物质生物合成调控机制奠定理论基础。

Objective The explore key genes involved in the biosynthesis of key flavonoids in Citrus medica through integrated transcriptomic and metabolomic analysis, and to provide a basis for further investigating the regulatory mechanism of flavonoid biosynthesis in fingered citron.Methods The transcriptome was sequenced by Illumina HiSeqTM 4 000 high-throughput sequencing platform for the fruit tissues at different developmental stages, and the flavonoids were characterized by LC-MS/MS technology. The key genes for biosynthesis of flavonoids were fully explored through KEGG database and association analysis.Results A total of 21 differentially expressed flavonoids and 25 differentially expressed genes were obtained by metabolomics and transcriptomic analysis, and there were significant differences in metabolites and key genes in the three periods. In the biosynthesis pathway of the flavonoids, the contents of nerogenin-7-O-glucoside, eriocitrin, naringin, meringin, hesperidin-3-O-glucoside gradually decreased with the development of fruit, while the contents of apigenin-5-O-glucoside and luteinin-4-O-glucoside gradually increased with the development of fruit. Key enzyme genes such as phenylalanine ammonialyase (PAL), 4-coumarate coenzyme A ligase (4CL), chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), flavonoid 3’-hydroxylase (F3’H), flavone synthase (FNS), anthocyanidin synthase (ANS), and UDP-glycosyltransferases (UGTs) were successfully identified in the metabolic pathway of the flavonoids. PAL, 4CL, CHS, F3H, FNS negatively regulate downstream metabolites, which CHI and UGTs positively regulate downstream metabolites, all of which are significantly correlated with downstream metabolites.Conclusion The differential expression patterns of flavonoid metabolites and related genes in different developmental stages were revealed, which laid a theoretical foundation for elucidating the regulation mechanism of flavonoid biosynthesis in Citrus medica 'Fingered'.

R286.12

重庆市技术创新与应用发展重点项目（cstc2021jscx-gksbX0015）