Effects of Precursor, Temperature, and Illumination on Theanine Accumulation in Tea Callus

Abstract

The theanine (THE: γ-glutamylethylamide) accumulation level was greatly increased in tea callus when ethylamine hydrochloride (EtNH₂•HCl) was added to the medium. The optimum temperature for THE accumulation was the same temperature (25°C) as for growth of callus. Little THE was discharged into the medium. Dark culture was better than illumination for the accumulation of THE (201 mg/g dry wt.). These results suggested that THE synthetase had a positive activity, the decrease of THE content in callus was caused by the lowering of EtNH₂ biosynthesis level, and temperature and illumination strongly affected THE accumulation.