Loewe Anja, Einig Werner, Shi Lanbo, Dizengremel Pierre, Hampp Rüdiger
1 Physiologische Ökologie der Pflanzen, Botanisches Institut, Universität Tübingen, Auf der Morgenstelle 1, D-72076 Tübingen, Germany.
New Phytol. 2000 Mar;145(3):565-574. doi: 10.1046/j.1469-8137.2000.00598.x.
The effects of mycorrhiza formation in combination with elevated CO concentrations on carbon metabolism of Norway spruce (Picea abies) seedlings and aspen (Populus tremula×Populus tremuloides) plantlets were analysed. Plants were inoculated for 6 wk with the ectomycorrhizal fungi Amanita muscaria and Paxillus involutus (aspen only) in an axenic Petri-dish culture at 350 and 700 μl l CO partial pressure. After mycorrhiza formation, a stimulation of net assimilation rate was accompanied by decreased activities of sucrose synthase, an increased activation state of sucrose-phosphate synthase, decreased fructose-2,6-bisphosphate and starch, and slightly elevated glucose-6-phosphate contents in source leaves of both host species, independent of CO concentration. Exposure to elevated CO generally resulted in higher net assimilation rates, increased starch as well as decreased fructose-2,6-bisphosphate (aspen only) content in source leaves of both mycorrhizal and nonmycorrhizal plants. Our data indicate only slightly improved carbon utilization by mycorrhizal plants at elevated CO . They demonstrate however, that both factors which modulate the sink-source properties of plants increase the capacity for sucrose synthesis in source leaves mainly by allosteric enzyme regulation.
分析了菌根形成与升高的二氧化碳浓度相结合对挪威云杉（Picea abies）幼苗和山杨（Populus tremula×Populus tremuloides）组培苗碳代谢的影响。在无菌培养皿中，将外生菌根真菌毒蝇鹅膏和卷缘桩菇（仅用于山杨）接种到植物上6周，二氧化碳分压分别为350和700 μl l。菌根形成后，两种寄主植物的源叶中，净同化率的提高伴随着蔗糖合酶活性的降低、蔗糖磷酸合酶激活状态的增加、果糖-2,6-二磷酸和淀粉含量的降低以及葡萄糖-6-磷酸含量的略微升高，且与二氧化碳浓度无关。暴露于升高的二氧化碳环境中，菌根和非菌根植物的源叶通常会有更高的净同化率、增加的淀粉含量以及降低的果糖-2,6-二磷酸（仅山杨）含量。我们的数据表明，在升高的二氧化碳环境下，菌根植物的碳利用仅略有改善。然而，它们表明，这两个调节植物源库特性的因素主要通过变构酶调节增加了源叶中蔗糖合成的能力。
