Department of Biology, Faculty of Science, Kyushu University, Higashi-ku, Fukuoka 812, Japan.
Plant Physiol. 1992 Apr;98(4):1494-7. doi: 10.1104/pp.98.4.1494.
Ion channels in tonoplast of leaf cells of a Crassulacean acid metabolism plant, Graptopetalum paraguayense, using the patch clamp technique were investigated. Results showed the existence of two types of channels involved in the malate ion transport across the tonoplast. One type corresponded to the slow-activating vacuolar-type (R Hedrich, E Neher [1987] Nature 329: 833-836), probably taking part in the malate efflux from vacuoles. Another showed the membrane potential-dependent channel current of malate flux over a wide range of cytoplasmic free Ca(2+) concentration (10(-8)-10(-5) molar), a property favoring the malate uptake. This type seems to be different from the fast-activating vacuolar-type.
使用膜片钳技术研究了景天酸代谢植物落地生根叶片细胞液泡膜上的离子通道。结果表明,存在两种参与液泡膜上苹果酸离子转运的通道。一种类型与慢激活的液泡型(R Hedrich,E Neher [1987] Nature 329: 833-836)相对应,可能参与了苹果酸从液泡中的外排。另一种则表现出对细胞质游离 Ca(2+)浓度(10(-8)-10(-5)摩尔)有广泛依赖性的膜电位依赖的苹果酸流通道电流,这一特性有利于苹果酸的摄取。这种类型似乎与快速激活的液泡型不同。