不同海拔高度祁连圆柏和青海云杉叶片色素的变化特征

利用高效液相色谱法(high performance liquid chromatography,HPLC)和酶标仪等测定了祁连山区不同海拔高度下祁连圆柏(Sabina przewalskii)和青海云杉(Picea crassifolia)叶片中色素含量、花青苷合成酶苯丙氨酸解氨酶(phenylalanine ammonialyase,PAL)和类黄酮糖基转移酶(UDP glucose-flavonoid 3-O-glucosyFtransferase,UFGT)活性.结果表明:两树种花青苷(anthocyanin,Acy)含量除了在海拔高度3100-3200 m有所升高外,总体上随海拔高度上升而降低;UFGT活性除了在3000 m左右波动外,总体随海拔高度上升而升高;祁连圆柏PAL活性随海拔高度上升而升高,青海云杉PAL活性在海拔2800-3000 m时,随海拔高度上升而升高,当海拔高度高于3000 m时,随海拔高度上升而降低两树种紫松果黄素(rhodoxanthin,Rhd)含量、叶黄素循环(xanthophyll cycle,VAZ)的脱环氧化程度(A+Z)/(V+A+Z)比值和类胡萝卜素(carotenoids,Car)含量随海拔高度上升而升高;叶绿素(chlorophyll,Chl)含量随海拔高度上升而降低.除叶绿素含量和PAL活性外,其它指标都是祁连圆柏高于青海云杉,尤其是UFGT活性祁连圆柏是青海云杉的2倍多.不同海拔梯度、不同季节植物遭受的主导胁迫因子不同,8月份祁连山两树种主要受干旱和强光胁迫,色素主要发挥抗旱和抗辐射作用.由此说明植物色素在不同生境、不同季节发挥的作用不同.

Changes of Pigments in Sabina przewalskii and Picea crassifolia Needles Along with Different Altitudes

Using high performance liquid chromatography （HPLC） and microplate spectrophotometer, we determined variations in pigments and enzymes phenylalanine ammonialyase （PAL） and UDP glucose-flavonoid 3-O-glucosyl-trans- ferase （UFGT） involved in biosynthesis pathway of anthocyanins in Sabina pr＇zewalskii and Picea crassifolia along with altitude changes. The content of pigments and enzyme activity were dependent on the altitude： the anthocyanins （Acy） increased between 3 100-3 200 m, decreased with the increase of altitude in general. The enzyme activity of UFGT was increased with the increase of altitude while it fluctuated around 3 000 m. The enzyme activity of PAL in S. przewalskii was increased with the increase of altitude and the same pattern appeared in P. crassifolia between 2 800--3 000 m. The enzyme activity of PAL in P. crassifolia was decreased with the increase of altitude above 3 000 m. Contents of rho- doxanthin （Rhd） and carotenoids （Car）, de-epoxidation index （A＋Z）/（V＋A＋Z） were higher with higher altitude. The content of chlorophyll （Chl） had an opposite pattern： decreased with increasing altitude. Except for chlorophyll and PAL, the nee- dles of S. przewalskii contained higher pigments than those of P. crassifolia. It was noted that the level of UFGT activity in S. przewalskii was twice that in P. crassifolia. Plants would encounter various environmental stresses caused by different altitude and season. Drought and strong sunlight are dominant in August for two species of Qilian Mountain. These pig- ments are mainly for anti-drought and prevent strong sunlight. Therefore, the role of pigments depends on when and where these plants inhabit.