水解酪蛋白和水杨酸对百里香生理代谢及精油提取率的影响

Effects of casein hydrolysate and salicylic acid on physiology metabolism and extraction ratio of essential oil of Thymus vulgaris L.

目的研究水解酪蛋白和水杨酸对离体培养的百里香不定芽增殖以及不定芽中生理代谢和精油含有量的影响。方法添加不同质量浓度的水解酪蛋白或水杨酸后,测定百里香不定芽可溶性糖、可溶性蛋白含有量、相关酶活性以及百里香精油含有量。结果水解酪蛋白和水杨酸都能不同程度促进不定芽的增殖,其中以添加300 mg/L水解酪蛋白和0.5 mg/L水杨酸的增殖效果最佳,增殖系数分别比对照显著增加51.05%、20.71%。与对照处理相比,可溶性糖含有量降低,可溶性蛋白则增加,超氧化物歧化酶(SOD)、过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)活性上升,多酚氧化酶(PPO)活性下降。从增殖的不定芽中水蒸气蒸馏出精油,百里香不定芽的精油提取率分别达到0.38%,0.41%,对照组为0.31%。结论水解酪蛋白和水杨酸不仅提高了百里香不定芽的增殖,而且还促进了百里香次生代谢产物的积累和合成。

AIM To study the effects of casein hydrolysate and salicylic acid on propagation,physiology metabolism and essential oil yield of adventitious buds of Thymus vulgaris in vitro.METHODS The contents of soluble sugar,soluble protein and enzymatic activity were measured adding casein hydrolysate and salicylic acid into the culture medium of adventitious buds of Thymus vulgaris.RESULTS The results showed that casein hydrolysate and salicylic acid could help adventitious buds proliferation,and the best concentrations were 300 mg/L of casein hydrolysate and 0.5 mg/L of salicylic acid.Proliferation coefficient significantly increased 51.05% and 21.71%,respectively.Casein hydrolysate and salicylic acid increased the contents of soluble protein and the activity of superoxide dismutase,peroxidase,phenylalnine ammonialyase but decreased the content of soluble sugar and the activity of polyphenoloxidase.Steam distillation was used to extract the essential oil.Its oil yield reached 0.38% and 0.41%,respectively,and was higher than the control group（0.31%）.CONCLUSION This study shows that addition of suitable concentration of casein hydrolysate and salicylic acid could increase proliferation of adventitious buds of Thymus vulgaris and also promote the accumulation and synthesis of secondary metabolites in thyme.