Turnau K, Berger A, Loewe A, Einig W, Hampp R, Chalot M, Dizengremel P, Kottke I
Institute of Botany of the Jagiellonian University, Krakow, Poland.
Tree Physiol. 2001 Feb;21(2-3):93-9. doi: 10.1093/treephys/21.2-3.93.
We studied the influence of elevated atmospheric CO2 concentration ([CO2]) on the vacuolar storage pool of nitrogen-containing compounds and on the glycogen pool in the hyphal sheath of Amanita muscaria (L. ex Fr.) Hooker-Picea abies L. Karst. mycorrhizae grown with two concentrations of ammonium in the substrate. Mycorrhizal seedlings were grown in petri dishes on agar containing 5.3 or 53 mg N l(-1) and exposed to 350 or 700 microl CO2 l(-1) for 5 or 7 weeks, respectively. Numbers and area of nitrogen-containing bodies in the vacuoles of the mycorrhizal fungus were determined by light microscopy linked to an image analysis system. The relative concentration of nitrogen in the vacuolar bodies was measured by electron energy loss spectroscopy (EELS). Glycogen stored in the cytosol was determined at the ultrastructural level by image analysis after staining the sections (PATAg test). Shoot dry weight, net photosynthesis and relative amounts of N in vacuolar bodies were greater at the higher N and CO2 concentrations. The numbers and areas of vacuolar N-containing bodies were significantly greater at the higher N concentration only at ambient [CO2]. In the same treatment the percentage of hyphae containing glycogen declined to nearly zero. We conclude that, in the high N/low [CO2] treatment, the mycorrhizal fungus had an insufficient carbohydrate supply, partly because of increased amino acid synthesis by the non-mycorrhizal rootlets. When [CO2] was increased, the equilibrium between storage of glycogen and N-containing compounds was reestablished.
我们研究了大气中二氧化碳浓度（[CO₂]）升高对毒蝇鹅膏菌（Amanita muscaria (L. ex Fr.) Hooker）-欧洲云杉（Picea abies L. Karst.）菌根菌套中含氮化合物液泡储存池和糖原池的影响，该菌根在含有两种铵浓度的基质中生长。菌根幼苗在含有5.3或53 mg N l⁻¹的琼脂培养皿中生长，并分别暴露于350或700 μl CO₂ l⁻¹环境中5或7周。通过与图像分析系统相连的光学显微镜确定菌根真菌液泡中含氮体的数量和面积。通过电子能量损失谱（EELS）测量液泡体中氮的相对浓度。在对切片进行染色（PATAg试验）后，通过图像分析在超微结构水平上测定储存在细胞质中的糖原。在较高的氮和二氧化碳浓度下，地上部干重、净光合作用和液泡体中氮的相对含量更高。仅在环境[CO₂]下，较高氮浓度时液泡含氮体的数量和面积显著更大。在相同处理中，含有糖原的菌丝百分比降至近零。我们得出结论，在高氮/低[CO₂]处理中，菌根真菌的碳水化合物供应不足，部分原因是非菌根小根氨基酸合成增加。当[CO₂]增加时，糖原和含氮化合物储存之间的平衡得以重新建立。
