Outlaw W H, Manchester J
Plant Biology Program, Department of Biology (Box 1137), Washington University, Saint Louis, Missouri 63130.
Plant Physiol. 1979 Jul;64(1):79-82. doi: 10.1104/pp.64.1.79.
Using quantitative histochemical techniques, the carbohydrate levels of guard cells from open and closed stomatal apparatus of Vicia faba L. were compared. To minimize experimental error, all comparisons were between leaflets of the same pair. Stomata on one leaflet were caused to open by light and reduced CO(2). The other leaflet, which was in darkness, had closed stomata. In one experiment, data were also collected on palisade parenchyma, spongy parenchyma, and epidermal cells.Guard cell starch concentration was higher in the leaflets with closed stomata than in open stomata by 72 +/- 16 millimoles per kilogram dry weight (anhydroglucosyl equivalents) (N = 117, P < 0.02). Variation in guard cell starch concentration from one part of a leaflet to another was small. The data are consistent with the hypothesis that starch degradation provides the carbon skeletons for anion synthesis in guard cells during stomatal opening.Sucrose concentration was higher in guard cells when stomata were open than when they were closed in all three experiments (average difference = 45 +/- 7 millimoles per kilogram dry weight [N = 59, P < 0.01]). The variability of sucrose concentration within test leaflets prevented an unequivocal interpretation of these results. When all data are considered, it appears that soluble sugars increase in guard cells when stomata of Vicia faba open.
运用定量组织化学技术，比较了蚕豆开放和关闭气孔装置保卫细胞中的碳水化合物水平。为尽量减少实验误差，所有比较均在同一对小叶之间进行。一片小叶上的气孔通过光照和降低二氧化碳浓度使其开放。另一片处于黑暗中的小叶，其气孔是关闭的。在一项实验中，还收集了栅栏薄壁组织、海绵薄壁组织和表皮细胞的数据。关闭气孔的小叶中保卫细胞淀粉浓度比开放气孔的小叶高72±16毫摩尔/千克干重（脱水葡萄糖基当量）（N = 117，P < 0.02）。小叶不同部位保卫细胞淀粉浓度的变化很小。这些数据与淀粉降解为气孔开放期间保卫细胞中阴离子合成提供碳骨架这一假说相符。在所有三项实验中，开放气孔时保卫细胞中的蔗糖浓度高于关闭气孔时（平均差异 = 45±7毫摩尔/千克干重 [N = 59，P < 0.01]）。测试小叶内蔗糖浓度的变异性使得对这些结果的明确解释变得困难。综合所有数据来看，蚕豆气孔开放时保卫细胞中的可溶性糖似乎会增加。
