摘要
离体培养条件下 ,用脯氨酸类似物羟脯氨酸 ( HYP) 2 0 mmol/L作选择压力 ,筛选出羊草( Aneurolepidium chinense( Trin.) Kitag.)抗 HYP细胞变异系 HR2 0 - 8。其游离脯氨酸含量比供体提高 6.6倍 ,而且抗 Na Cl、PEG及低温的能力也较供体增强。对变异系脯氨酸合成途径进行分析 ,发现其中控制第一步反应的关键酶—— -谷氨酸激酶的活性异常增加 ,比供体高 2 .5倍。而且外源脯氨酸对变异系和供体的 -谷氨酸激酶的抑制表现得很相似。
A hydroxyproline(HYP) resistant cell line of Chinese aneurolepidium(Aneurolepidium chinense (Trin.) Kitag.) was isolated under selection pressure of 20 mmol/L HYP. Comparison of the free amino acid pool levels in the cell line with that of donor showed substantial accumulation of proline(6 6×).Enzyme examination indicated that glutamyl kinase controlling proline biosynthesis in HR20 8 cell line had 2 5 times as much activity as that of the donor. Exogenous L proline inhibited the enzyme activities both in the HR20 8 and the donor by the same rate of 30% at 100 mmol/L. The responses of HR20 8 cell line to NaCl,PEG and cold temperature (5℃) were also compared with those of donor and the former exhibited remarkably increased tolerance to the tested stress condition. The results showed that changes of glutamyl kinase property exhibited the phenomenon of extra accumulation of proline which might favor the increased tolerance to NaCl,PEG and cold temperature in the resistant cell line.
基金
国家自然科学基金
关键词
羊草
变异系
组织培养
脯氨酸
Chinese aneurolepidium
Variant line
Tissue culture
Proline
