Genomic and Metabolomic Insights into Volatile and Nonvolatile Metabolite Variation from Fresh Leaves to the Turning Stages in Wuyi Rock Tea “Rougui”

Wuyi rock tea is renowned for its distinctive ″rock
flavor,″
largely formed during the turning stage through mechanical stress
and enzymatic changes.To investigate its molecular basis, we assembled
the most contiguous tea genome to date from the representative cultivar
“Rougui” and identified structural variations distributed
across flavor-related genes and pathways. Metabolomic profiling highlighted
the fourth and fifth turning stages as critical, showing surges in
volatiles and nucleotides, rapid catechin and amino acid degradation,
and a striking 180-fold rise in theaflavins. Leveraging transcriptome
data with >97% mapping rate to the “Rougui” genome,
we identified 1248 genes forming key coexpression modules associated
with volatiles and theaflavins biosynthesis. These modules include
10 TPSs, PPO, POD, and multiple upstream structural genes that were
coordinately activated during the sequential turning stages. The results
offer genomic resources and insights into the regulation of flavor
formation in Wuyi rock tea.