中文摘要：

以青藏高原特有植物肋果沙棘试管苗为试材,研究了4℃低温胁迫（0~72h）对其叶片黄酮类化合物合成关键酶苯丙氨酸解氨酶（PAL）、肉桂酸4-羟基化酶（C4H）及4-香豆酸辅酶A连接酶（4CL）活性的影响。结果表明：短期的低温胁迫显著影响肋果沙棘试管苗叶片PAL、C4H和4CL的活性。胁迫初期,PAL和C4H活性波动较大,PAL活性在12h达到最高值,24h时活性最低,比对照降低了63.514%,之后其活性逐渐恢复;C4H活性在处理12h时降到最低,此后逐渐升高,72h时其活性是对照的447.2%;4CL活性在胁迫6h时达到最高值,比对照高出了36.285%,之后缓慢下降并最终低于对照。肋果沙棘试管苗叶片PAL、C4H和4CL以不同的方式对低温胁迫进行了响应,苯丙烷类代谢被激活,调控黄酮类等次生代谢物质的合成。

英文摘要：

Test-tube plantlets leaves of Hippophae neurocarpa was used as materials,activities of three key enzymes related to flavonoids,phenylalanine ammonialyase（PAL）,4-hydroxy cinnamic acid enzyme（C4H）and 4-Coumadin acid coenzyme A ligase（4CL）were tested under low temperature in test-tube plantlets leaves of Hippophae neurocarpa.The results showed that the three enzymes could be affected easily under low temperature.In the early stage of stress,activities of PAL and C4 Hfluctuated greatly.The activity of PAL reached the highest value at 12 hours and got the lowest value by 24 hours,which was 63.514%lower than that of control.Its activity recovered gradually afterwards.The activity of C4 Hgot the lowest value at 12 hours and began to increase after that.Its activity was 447.2%of the control by 72 hours.The activity of 4CL reached the highest after 6hours and was 36.285% higher than that of control.The activity of 4CL decreased after that and was lower than that of control at last.The activities of PAL,C4 Hand 4CL in test-tube plantlets leaves of Hippophae neurocarpachanged in different ways under low temperature.Phenylaprapanoid metabolism was activated and synthesis of secondary metabolites such as flavonoids could be regulated.