Integrated metabolomic and transcriptomic analyses reveal cultivar-specific molecular responses of tea plants growing in Northern China.

backgroundTea (Camellia sinensis) is traditionally cultivated in subtropical regions. Tea cultivation in northern China, particularly in Ju’nan county, faces climatic challenges that differ from traditional southern tea-growing regions. Understanding how tea cultivars adapt to these novel environments is essential for region-specific cultivar improvement. However, the molecular and metabolic mechanisms underlying tea cultivars’ responses to the novel environmental conditions remain poorly understood.

resultsIn this study, metabolomics and transcriptomic approaches were performed on the young shoots, mature leaves, tap roots and fibrous roots of ‘Zhongcha108’ (ZC), ‘Fuding Dabaicha’ (FD), and ‘Jiukeng’ (JK) tea cultivars growing in Ju’nan region. The results revealed that the three cultivars exhibited distinct metabolic patterns, with significant differences in metabolite levels across tissues and enrichment in different metabolic pathways. The differential expression of genes in the phenylpropanoid biosynthetic pathway might led to the different lignin biosynthesis. The expression patterns of genes in the flavonoid biosynthetic pathway were consisted with the accumulation of flavonoids. FD roots exhibited enhanced fatty acid accumulation and elevated expression of key biosynthetic genes. Additionally, AP2/ERF-ERF, zf-HD, MYB44-like, and Tify transcription factors showed cultivar-specific and fine-tuned regulatory roles in modulating phenylpropanoid and flavonoid biosynthesis, as well as the fatty acid metabolism network in tea plants.

conclusionsThis study clearly reflected the unique biochemical characteristics and transcriptional regulation of each cultivar for responding to northern tea-growing environments. The findings provide an important theoretical basis and new molecular targets for enhancing regional adaptability in tea plant breeding.