Bender J, Manderscheid R, Jäger H J
Institut für Produktions-und Okotoxikologie der Bundesforschungsanstalt für Landwirtschaft, Braunschweig-Völkenrode (FAL), Bundesallee 50, D-3300 Braunschweig, Germany.
Environ Pollut. 1990;68(3-4):331-43. doi: 10.1016/0269-7491(90)90035-b.
Enzymatic activity (peroxidase, glutamate dehydrogenase, glutamine synthetase), foliage buffering capacity, soluble protein and nitrogen content were measured in current and previous year needles from young spruce (Picea abies) and fir (Abies alba). The trees were exposed to low levels of SO(2) and/or O(3) and simulated acidic precipitation (pH 4.0) in open-top chambers from 1983 through 1988. Needle samples were taken during March 1988 at the end of the five-year fumigation period. Exposure to SO(2) substantially increased sulphur content in both needle age classes of spruce and fir, and concomitantly reduced the foliage buffering capacity index (BCI), whereas the combined fumigation with SO(2) and O(3) had no effect on BCI. Peroxidase activity was markedly higher in year-old needles compared to current-year needles. However, trees from the SO(2) and SO(2) + O(3) treatments exhibited statistically significant stimulated peroxidase activities. Similarly, changes in the activities of the nitrogen-metabolizing enzymes indicated an altered cellular function of the trees after the long-term pollution stress. Levels of activity of both glutamate dehydrogenase and glutamine synthetase were increased by exposure to SO(2), especially in spruce. Although glutamate dehydrogenase in spruce was affected by all treatments, such changes in activity were found in fir only with the SO(2) treatment. The highest activity of glutamine synthetase, however, occurred in the older needles of trees exposed to SO(2) + O(3). Total nitrogen concentration was either unaffected by the pollutant treatments or decreased in spruce compared to the controls. No statistically significant changes due to the fumigation were found in soluble protein concentrations. Results indicated that chronic exposure to air pollutants lead to alterations in metabolic processes in conifer needles, detectable either by changes in typical stress indicating values or by increases in ammonium assimilation capacity.
对年轻云杉（欧洲云杉）和冷杉（欧洲冷杉）当年和上一年的针叶进行了酶活性（过氧化物酶、谷氨酸脱氢酶、谷氨酰胺合成酶）、叶片缓冲能力、可溶性蛋白和氮含量的测定。从1983年到1988年，这些树木在开放式顶篷箱中暴露于低水平的二氧化硫和/或臭氧以及模拟酸性降水（pH 4.0）环境中。1988年3月在五年熏蒸期结束时采集针叶样本。暴露于二氧化硫使云杉和冷杉两个针叶年龄组的硫含量大幅增加，并相应降低了叶片缓冲能力指数（BCI），而二氧化硫和臭氧联合熏蒸对BCI没有影响。与当年针叶相比，一年生针叶中的过氧化物酶活性明显更高。然而，来自二氧化硫和二氧化硫+臭氧处理组的树木表现出具有统计学意义的过氧化物酶活性增强。同样，氮代谢酶活性的变化表明，长期污染胁迫后树木的细胞功能发生了改变。暴露于二氧化硫会增加谷氨酸脱氢酶和谷氨酰胺合成酶的活性水平，尤其是在云杉中。虽然云杉中的谷氨酸脱氢酶受到所有处理的影响，但仅在二氧化硫处理的冷杉中发现了这种活性变化。然而，谷氨酰胺合成酶的最高活性出现在暴露于二氧化硫+臭氧的树木的老针叶中。总氮浓度要么不受污染物处理的影响，要么与对照相比在云杉中有所降低。熏蒸处理未发现可溶性蛋白浓度有统计学意义的变化。结果表明，长期暴露于空气污染物会导致针叶代谢过程发生改变，这可以通过典型胁迫指示值的变化或铵同化能力的增加来检测。
