Tea lovers rejoice! Scientists have discovered a way to preserve the freshness and flavor of late-spring tea, unlocking the secret of theanine metabolism in tea plants.
Tea, cherished worldwide for its soothing taste and calming effects, gets much of its unique flavor from theanine, an amino acid. Theanine adds a delicate sweetness that balances the bitterness of other compounds like catechins and caffeine. It also promotes relaxation and better sleep.
But there’s a catch: theanine levels are high in early spring when new tea shoots emerge, but they significantly decrease in late spring. This drop leads to a decline in the quality of green tea harvested later in the season. For years, scientists couldn’t figure out why this happened.
Now, a team led by Professor Zhang Zhaoliang at Anhui Agricultural University has cracked the case. Their groundbreaking research, published in the journal The Plant Cell, reveals how theanine is metabolized in tea plants during the spring.
During the rapid growth of spring, tea plants use theanine as a nitrogen source to develop new shoots. The process begins with a transporter protein called CsTHS1, which moves theanine from the cell’s cytoplasm into the mitochondria—the cell’s powerhouse. Once inside, an enzyme named CsGGT2 breaks down theanine, reducing its levels in the plant.
Temperature plays a crucial role in this process. As the weather warms, both CsTHS1 and CsGGT2 become more active, accelerating the degradation of theanine.
This discovery opens up new possibilities for improving the flavor of late-spring tea. “We can use gene editing for precision breeding, or develop special fertilizers and shading techniques to maintain theanine levels for smarter cultivation of premium spring teas,” Professor Zhang said.
For tea enthusiasts and farmers alike, this breakthrough could mean more fresh and flavorful tea throughout the spring season.
