茶树种质资源汝城白毛茶的代谢物差异研究

汝城白毛茶是湖南四大茶树地方群体资源之一，也是白毛茶变种（Camellia sinensis var. pubilimba Chang）的典型代表，已有研究表明汝城白毛茶在演化地位上与湖南其他3个地方群体资源差异较大，且在植物学特征、生化成分、制茶品质等方面特色鲜明。但目前对汝城白毛茶种质资源次生代谢物的差异研究较少。本研究采用UPLC-MS/MS分析技术，以汝城白毛茶为研究对象，湖南典型地方茶树资源安化群体（AHQT, C. sinensis var. sinensis）、城步峒茶CBDC, C. sinensis var. assamica (Masters) Kitamura]、江华苦茶JHKC, C. sinensis var. assamica (Masters) Kitamura]为对照，筛选汝城白毛茶中的显著差异代谢物，并进行K均值聚类（K-means）分析和差异代谢物富集通路分析。结果表明，与AHQT、CBDC、JHKC相比，分别在汝城白毛茶中筛选到显著差异代谢物189、180、162个，种类最多的为黄酮类（69、51、60个），其次为酚酸类（31、40、25个），...

Metabonomic Analysis of Metabolic Differences in Rucheng Baimaocha Tea Germplasm

Rucheng Baimaocha (Camellia sinensis var. pubilimba Chang) is one of the four tea plants native to Hunan Province, China. Previous studies have shown that Rucheng Baimaocha is different from other three local population resources in Hunan in evolutionary status, and has distinctive characteristics in botanical characteristics, biochemical components and tea making quality. However, there are few studies on the differences of secondary metabolites of Rucheng Baimaocha germplasm resources. Using UPLC-MS/MS analysis technology, taking Anhua population (AHQT, C. sinensis var. sinensis), Chengbu Dongcha CBDC, C. sinensis var. assamica (Masters) Kitamura], and Jianghua Kucha JHKC, C. sinensis var. assamica (Masters) Kitamura] of typical local tea resources in Hunan as controls, the significantly different metabolites in Rucheng Baimaocha were screened and clustered by K-means analysis and differential metabolite enrichment pathway analysis. Compared with the control, 189, 180 and 162 significantly different metabolites were screened in Rucheng Baimaotea, the most species were flavonoids (69, 51 and 60 respectively), followed by phenolic acids (31, 40 and 25 respectively), and the least were lignans and coumarins (5, 4 and 4 respectively). Compared with the other three populations, Rucheng Baimaotea increased the content of 15 metabolites. The content of flavonoids and phenolic acids increased the most in Rucheng Baimaocha, and the highest increase was pinocembrin, followed by 1,2,3,6-tetra-o-galloyl-d-glucose. The differential metabolites were analyzed by K-means clustering. The metabolites with the same change trend in the four groups could be divided into nine categories. Among the four populations, there were 32 metabolites with the same change trend and the highest content in Rucheng Baimaotea, mainly flavonoids and tannins. The results of KEGG pathway enrichment of differential metabolites showed that the differential metabolites of Rucheng Baimaotea were mainly enriched in flavonoid biosynthesis pathway, flavonoid and flavonol biosynthesis pathway, phenylpropane biosynthesis pathway and so on. In addition to the differential metabolites reported in some tea, some differential metabolites less concerned in tea research were detected, such as pinocembrin, ellagic acid, kaempferol, etc. The substances would provide an important reference for the excavation and breeding of characteristic tea germplasm resources of Rucheng white tea in the later stage.