Tea tissue culture (B) Theanine and polyphenols accumulation in tea calli

Abstract

Camellia sinensis (L.) Kuntze is the crop plant used as the source for the popular beverage 'Tea'. The main active
component in tea responsible for its stimulating 'pick-me-up' effect on the brain is a unique non-protein amino acid called
Theanine. In the present study, the effect of theanine precursors - i.e., ethylamine and the ethylamine precursor alanine - on
theanine accumulation in tea callus was studied. The precursors were used both singly as well as in combination to observe a
potential synergistic effect. At a 15 day interval, callus cultured with 25 mM Ethylamine. HCl showed maximum increase in
theanine, 34.64 mg theanine/g dry weight of callus. However, at a 30 day interval, a synergy between ethylamine and alanine
was seen with maximum theanine accumulation in the callus grown on 25 mM Ethylamine. HCl + 25 mM L-alanine, 29.93
mg theanine/g dry weight of callus. At the same time, at the 30 day interval a decrease in theanine accumulation was observed
in callus grown on 25 mM Ethylamine. HCl with the theanine content falling to 23.14 mg theanine/g dry weight of callus. The
theanine content of the tea calli was also found to vary almost inversely with the polyphenol content of the tea caUi over the
duration of the 60 day culture cycle.