Institut für Botanik und Microbiologie der Technischen Universität München, Arcisstraße 21, D-8000, München 2, Federal Republic of Germany.
Planta. 1977 Jan;135(3):307-11. doi: 10.1007/BF00384905.
Because starch is absent from Allium-guard cells, another polysaccharide was sought that, in connection with stomatal opening, could be a source of organic anions. Analysis of isolated polysaccharides revealed xylose, arabinose, glucose, galactose, and galacturonic acid (3.4:1:1.6:0.7) to be components of the water-soluble mucilage of the epidermal strips of Allium cepa. However, the experiments gave no indication that the mucilage is the malate donator during the stomatal opening. After (14)CO2 fixation the following substances were labeled: organic acids, especially malate and citrate, amino acids and the polysaccharide mentioned above; radioactive 3-phosphoglyceric acid and sugar phosphates were not found. Therefore we conclude that the Calvin cycle does not operate in the guard cells of Allium cepa.
由于洋葱保卫细胞中不存在淀粉，因此需要寻找另一种多糖，这种多糖在与气孔开放有关的情况下可以作为有机阴离子的来源。对分离的多糖进行分析表明，洋葱表皮条带的水溶性黏液的成分是木糖、阿拉伯糖、葡萄糖、半乳糖和半乳糖醛酸（3.4:1:1.6:0.7）。然而，实验并未表明黏液是气孔开放期间苹果酸的供体。（14）CO2 固定后标记了以下物质：有机酸，特别是苹果酸和柠檬酸，氨基酸和上述多糖；未发现放射性 3-磷酸甘油酸和糖磷酸。因此，我们得出结论，卡尔文循环在洋葱保卫细胞中不起作用。
