以祁连圆柏(Sabina przewalskii)和圆柏(S. chinensis)为材料, 测定2种植物花青苷、类黄酮、紫松果黄素、叶绿素和
类胡萝卜素的含量及花青苷合成过程中关键酶苯丙氨酸解氨酶(PAL)和类黄酮糖基转移酶(UFGT)的活性, 并分析了各值的季节性变化。结果表明, 祁连圆柏和圆柏叶片中PAL及UFGT的活性、花青苷、类黄酮﹑紫松果黄素以及类胡萝卜素的含量在低温季节均明显高于其它季节; 叶绿素含量在低温季节低于其它季节; 并且祁连圆柏中花青苷含量及其合成酶PAL和UFGT的活性以及类黄酮、紫松果黄素和叶绿素含量始终高于圆柏。结果说明花青苷是圆柏属植物中具有抗冻特性的重要次生代谢物,是抵御低温和辐射胁迫的一种重要保护物质; 紫松果黄素等色素对圆柏属植物抵抗低温诱导的光抑制起重要作用。
We investigated leaves of Sabina przewalskii and Sabina chinensis for seasonal variations in the contents of anthocyanins (ANT), flavonoids (FLA), rhodoxanthins (RHO), chlorophylls (CHL) and carotenoids (CAR), as well as the activity of phenylalanine ammonialyase (PAL) and UDP glucose flavonoid glycosyltransferase (UFGT), the key synthetases of anthocyanins. The content of ANT and activities of PAL and UFGT were significantly higher in low-temperature months and were associated with changes in FLA, RHO and CAR of the two species. The variations in
CHL were the opposite. The contents of ANT, FLA, RHO, CAR and CHL and activity of PAL and UFGT in S. przewalskii
were higher than those in S. chinensis. The results suggested that ANT is an important secondary metabolite that has antifreezing properties and is an important protective substance that could resist low temperature and radiation stress. RHO and other pigments play an important role in resisting cold-induced photoinhibition.