双阻离子选择性微电极测定活体不结球小白菜叶片细胞中硝酸根离子的活度  

MEASUREMENT OF NITRATE ACTIVITY IN LEAF CELLS OF CHINESE CABBAGE IN VIVO USING DOUBLE-BARRELED NITRATE SELECTIVE MICROELECTRODES

作　　者：贾莉君[1] 范晓荣[1] 尹晓明[1] 曹云[1] 沈其荣[1] 

机构地区：[1]南京农业大学资源与环境科学学院,南京210095

出　　处：《土壤学报》2005年第3期447-452,共6页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(30270790)资助

摘　　要：详细介绍了用双阻离子选择性微电极活体测定小白菜叶片活体细胞中硝酸根离子的活度的方法原理及注意事项。微电极与溶液中硝酸根离子的浓度呈对数曲线的关系,斜率为48～58mV,对硝酸根离子浓度有较低的检出限,是一种选择性高、灵敏、经济的测定植物活体细胞中离子活度的方法。小白菜生长至六叶期时,用含有5molm-3NO3-的营养液诱导48h。测定结果表明,叶片细胞中硝酸根离子活度分布在活度高低明显不同的两个区间内,在细胞质中是0.24～10molm-3,液泡中20～110molm-3,且两个区间在细胞跨膜电位上也有差异。液泡占整个细胞体积的90%,所以,植物所吸收的硝酸根离子都集中在液泡中。Intracellular measurement of nitrate activity in leaf cells of Chinese cabbage in vivo using double-barreled nitrate selective microelectrode was reported for the first time in China. These microelectrodes showed a typical log linear response to nitrate concentration from 100 mol m -3 to 0.01mol m -3 with a slope of 48～58 mV and the nitrate activity detectable was very low. The microelectrode was characterized by a high selectivity and sensitivity of ion and a good economy compared with other intracellular measurements. In addition, the in vivo method is better than the chemical analysis of the samples. The detected results showed that nitrate activity in leaf cell of Chinese cabbage induced with 5 mol m -3 nitrate for 48h fell into two different populations, i.e. 0.24 mol m -3～10 mol m -3 in cytosol and 20 mol m -3～110 mol m -3 in vacuole. Since vacuolar volume accounts for 90% of a whole cell, most of the nitrate in plants is stored in vacuoles. And, thus it is of great importance to study the remobilization of the nitrate in vacuoles both in increasing nitrogen use efficiency and in decreasing the nitrate content of vegetables.

关 键 词：双阻离子选择性微电极 叶片细胞 硝酸根离子 不结球小白菜 活度测定 活体 

分 类 号：S132[农业科学—农业基础科学]