Chemical Changes In Young Tea Plant (Camellia sinensis L.) Tissues Following Application of Fertilizer Nitrogen

15N Study on the Fate of Foliarly Applied Urea Nitrogen in Tea Plant (Camellia sinensisL.)

“…Little is known about the N source utilized in the synthesis of theanine in the roots. The concentration of theanine in the xylem sap increased rapidly in response to ammonium sulfate application to the soil (14). A high level of 15N labeling in theanine was observed in the roots when the plants were supplied with 15N-labeled ammonium sulfate in the culture medium bathing the roots (6, Hoshina's personal communication).…”