The regulatory network on characteristic aroma formation during the processing of Meizhan oolong tea

Meizhan Oolong tea is renowned for its rich floral aroma. Understanding the key characteristic aromas of Meizhan Oolong tea and their formation mechanisms during post-harvest processing is help for the further utilization and quality improvement of the Meizhan cultivar. Here, we conducted an integrative analysis of the volatile metabolome and transcriptome during the processing of Meizhan Oolong tea. These results indicate that linalool, phenylacetaldehyde, jasmone, indole, and methyl nonyl ketone contribute to the characteristic aroma of the Meizhan oolong tea, with their accumulation primarily induced by the green-making process. The aroma of Meizhan Oolong tea is regulated by multiple transcription factors, among which CsMYB62 was identified as a hub gene, with its expression level increasing as processing progresses. Through DNA affinity purification sequencing and transcriptome sequencing analysis, 7754 direct target genes of CsMYB62, including those involved in various aspects of aroma formation, were identified. Notably, CsMYB62 can bind to the promoter regions of the CsHDS, CsCM, CsADT, and CsMAO genes, positively regulating the formation of linalool and phenylacetaldehyde. These findings increase our understanding of the regulatory mechanisms involved in the quality of Meizhan Oolong tea during postharvest processing.