Abstract: The differences between Bupleurum scorzonerifolium and B. chinense and their flavonoid biosynthesis pathway were studied by method of transcriptomics and metabolomics. Mass spectrometry imaging was used to investigate the in situ accumulation patterns of the major metabolites and intermediates of flavonoids. Results showed that the two species of Bupleuri Radix differed significantly, in which the flavonoid differential metabolites were regulated by differential genes and showed extreme variability, and 52 differential metabolites such as rutin, myricetin, sakuranetin and xanthohumol were screened, as well as differences in the pattern of in situ accumulation in the root cross-section, with the phloem of B. chinense being richer in flavonoid accumulation, and B. scorzonerifolium presenting a more homogeneous distribution profile. The mechanism of flavonoid biosynthesis in two species of Bupleuri Radix was revealed, and FLS, CHI and DFR genes were hypothesised to be the key genes in flavonoid biosynthesis. Meanwhile, analysis from the perspective of spatial distribution revealed that the accumulation of flavonoids in the root cross-section showed the characteristic of expanding outwards with the pith as the centre of the circle.

Key words: Bupleuri Radix, metabolomics, transcriptomics, mass spectrometry imaging, flavonoid biosynthesis

摘要： 通过转录组学和代谢组学分析不同基原柴胡样品的代谢物和基因表达差异性，探究其黄酮类化合物生物合成途径的调控机制。采用质谱成像技术分析黄酮类化合物主要的代谢产物及中间体的原位累积模式。结果表明，南北柴胡代谢物差异明显，其中黄酮类差异代谢物受差异基因调控，表现出极强的差异性，筛选出芦丁、杨梅素、樱花素、黄腐醇等52个差异代谢物，同时在根横切剖面原位累积模式也存在差异，北柴胡Bupleurum chinense的韧皮部黄酮类化合物积累较为丰富，南柴胡B. scorzonerifolium则呈现较为均匀的分布特征。不同基原柴胡的黄酮类生物合成的关键基因可能是FLS、CHI、DFR等。从空间分布来看，柴胡黄酮类化合物在根部横切面上的积累呈现以髓部为圆心向外扩展的特征。

关键词: 柴胡, 代谢组学, 转录组学, 质谱成像, 黄酮生物合成