Bloom A J
Department of Biological Sciences, Stanford University, Stanford, California 94305.
Plant Physiol. 1979 Dec;64(6):919-23. doi: 10.1104/pp.64.6.919.
Both laboratory- and field-grown Mesembryanthemum crystallinum plants exhibited large scale diurnal ion fluctuations. In mesophyll tissue, potassium and sodium levels varied in conjunction with acid levels while chloride levels varied in opposition. Thus, dark CO(2) fixation in this Crassulacean acid metabolism species seems analogous to the common plant process of malate synthesis to balance cation surplus. Sodium levels in the epidermis appeared to fluctuate in opposition to those in the mesophyll. It is proposed that inorganic cations cycle between mesophyll and epidermal tissue to balance malate accumulation and to produce stomatal opening in the dark.
实验室培育和田间种植的冰叶日中花植株均表现出大规模的昼夜离子波动。在叶肉组织中,钾和钠的水平随酸水平的变化而变化,而氯的水平则相反。因此,这种景天酸代谢植物中的暗CO₂固定似乎类似于普通植物中苹果酸合成以平衡阳离子过剩的过程。表皮中的钠水平似乎与叶肉中的钠水平呈相反波动。有人提出,无机阳离子在叶肉和表皮组织之间循环,以平衡苹果酸的积累并在黑暗中促使气孔开放。