Integrated metabolomic and transcriptomic analyses provide new perspectives into the discoloration of hawk tea tender leaves.

backgroundIn Southwest China, the spring-colored leaves of the Lauraceae plant Litsea coreana, often known as hawk tea, produce a traditional beverage with cultural and economic significance. Its immature leaves are generally red or green coloration, transitioning to common green as they mature. The possible quality benefits of high-anthocyanin tea cultivars with unusual leaf hues have recently drawn attention. It is important from a scientific and practical standpoint to clarify the metabolism and manufacture of pigments in hawk tea leaves that have different starting hues during the developmental stages.

resultsThis study applied both targeted metabolomics and transcriptomics to investigate the metabolite accumulation and molecular mechanisms in red and green hawk tea tender leaves across three developmental stages. Metabolomic profiling revealed that cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside, and pelargonidin-3-O-glucoside specifically accumulated in red tender leaves (2.44 to 4.59 Log

conclusionOur findings identify that red leaf color in L. coreana is driven by anthocyanin accumulation, which is achieved through a metabolic shift that directs carbon flux away from lignin and toward anthocyanin biosynthesis. This shift is likely regulated by a set of nine transcription factors. These findings provide concrete targets for breeding high-anthocyanin hawk tea varieties.