Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China.
Int J Mol Sci. 2018 May 15;19(5):1471. doi: 10.3390/ijms19051471.
To assess the interrelation between the change of metabolites and the change of fruit color, we performed a combined metabolome and transcriptome analysis of the flesh in two different cultivars: "HB" ("Hongbaoshixing") and "YF" ("Yongfengyihao") at two different fruit developmental stages: 70d (days after full bloom) and 100d (days after full bloom). Metabolite and transcript profiling was obtained by ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometer and high-throughput RNA sequencing, respectively. The identification and quantification results of metabolites showed that a total of 28,837 metabolites had been obtained, of which 13,715 were annotated. In comparison of HB100 vs. HB70, 41 metabolites were identified as being flavonoids, 7 of which, with significant difference, were identified as bracteatin, luteolin, dihydromyricetin, cyanidin, pelargonidin, delphinidin and (-)-epigallocatechin. Association analysis between metabolome and transcriptome revealed that there were two metabolic pathways presenting significant differences during fruit development, one of which was flavonoid biosynthesis, in which 14 structural genes were selected to conduct expression analysis, as well as 5 transcription factor genes obtained by transcriptome analysis. RT-qPCR results and cluster analysis revealed that , , , , , and showed the best possibility of being candidate genes. A regulatory network of flavonoid biosynthesis was established to illustrate differentially expressed candidate genes involved in accumulation of metabolites with significant differences, inducing red coloring during fruit development. Such a regulatory network linking genes and flavonoids revealed a system involved in the pigmentation of all-red-fleshed and all-green-fleshed , suggesting this conjunct analysis approach is not only useful in understanding the relationship between genotype and phenotype, but is also a powerful tool for providing more valuable information for breeding.
为了评估代谢物变化与果实颜色变化之间的相互关系，我们对两个不同品种（“HB”（红宝兴）和“YF”（永丰义号））在两个不同果实发育阶段（70d（盛花后）和 100d（盛花后））的果肉进行了代谢组学和转录组学联合分析。代谢物和转录物谱的获取分别通过超高效液相色谱四极杆飞行时间串联质谱仪和高通量 RNA 测序进行。代谢物的鉴定和定量结果表明，共获得了 28837 种代谢物，其中 13715 种被注释。在 HB100 与 HB70 的比较中，鉴定出 41 种代谢物为类黄酮，其中 7 种差异显著，分别为荭草苷、木樨草素、二氢杨梅素、矢车菊素、天竺葵素、飞燕草素和（-）表儿茶素。代谢组学和转录组学之间的关联分析表明，在果实发育过程中有两条代谢途径存在显著差异，其中一条是类黄酮生物合成途径，在此途径中选择了 14 个结构基因进行表达分析，并通过转录组分析获得了 5 个转录因子基因。RT-qPCR 结果和聚类分析表明， 、 、 、 、 和 最有可能成为候选基因。建立了一个类黄酮生物合成调控网络，以说明参与差异表达候选基因的代谢物的积累与果实发育过程中的颜色变化有关，从而诱导果实变红。这种将基因与类黄酮联系起来的调控网络揭示了一个与全红果肉和全绿果肉品种的色素沉着有关的系统，表明这种联合分析方法不仅有助于理解基因型与表型之间的关系，而且为育种提供更有价值的信息。
