Effects of exogenous compounds on the synthesis of theanine after added into culture media | 培养基中添加相关外源物对茶氨酸生物合成的影响

Chinese. 摘　　要：以龙井43的嫩叶等为材料,考察在培养基中添加茶氨酸合成前体物、代谢中间物及NO供体硝普钠对愈伤组织中茶氨酸含量的影响,并研究水培苗中添加一定浓度的硫酸铵对茶氨酸含量的影响。结果表明：培养基中添加25 mmol/L的盐酸乙胺可促进茶氨酸的合成,特别是在培养的第6-12天,愈伤组织中茶氨酸的含量增加明显,培养至第12天时,茶氨酸的含量最高,为108.96μmol/g（以干质量计）,是对照的7.72倍;培养基中分别添加低浓度的谷氨酰胺、丙氨酸及谷氨酸钠可在一定程度上提高愈伤组织中的茶氨酸含量,其中添加5 mmol/L的谷氨酰胺时增加最为明显,茶氨酸含量是对照的近7倍;培养基中添加0.05或0.075 mmol/L的硝普钠时,茶氨酸的含量有所增加,但总体水平较低。水培苗营养液中添加硫酸铵至100 mg/L时,茶苗培养3 d时的茶氨酸含量是对照的2.25倍。

English. The effects of precursors,metabolic intermediate of theanine synthesis and the NO donor SNP（sodium nitroprusside）on the synthesis of theanine in tea callus were investigated by using HPLC（high performance liquid chromatography） to detect theanine contents,and an accumulation of theanine in the roots of tea plants with different cultivation time after addition of（NH4）2SO4 into cultivation liquid was also discussed.As a result,25 mmol/L ZtNH2・HCl（ethylamine hydrochloride） could increase the content of theanine in callus significantly,especially in the callus grown from the 6th day to the 12th day.The theanine concentration in callus which grown for 12 days with addition of 25 mmol/L ZtNH2・HCl reached 108.96 μmol/g in dry weight basis,7.72 times of that in the control;addition of glutamine,alanine or sodium glutamate into medium with low concentrations could also increase theanine in callus,but the increasing amount was not very obvious compared to that with addition of 25 mmol/L ZtNH2・HCl with the exception of 5 mmol/L glutamine,which could boost the theanine to 7 times of that in the control.Addition of SNP with concentration of 0.05 or 0.075 mmol/L could increase the content of theanine in callus,but the increase amount was low in general.With addition of（NH4）2SO4 to 100 mg/L into cultivation liquid,the theanine content in tea plants was 2.25 times of that in the control on the 3rd day of the cultivation.The materials obtained with different theanine contents in this study could be used as materials for discovery of the genes correlated with theanine metabolism using digital gene expression profile in the future.