Leaf Structure in Relation to Solute Transport and Phloem Loading

本研究的两个主要目的是确定（1） 接着是光合作用细胞中产生的糖 （叶肉细胞）到食物传导细胞（筛管 成员）的叶脉，和（2）的网站，其中糖是 主动分泌，或加载，并卸载在成熟（源）， 未成熟的（汇）叶，分别。 详细的结构研究， 与光和电子显微镜，补充实验 研究，包括14 C标记的糖在叶内的定位 通过显微放射自显影术;旨在确定 各种细胞类型的溶质（主要是糖）浓度;以及 使用荧光染料来确定物质是否从 细胞与细胞通过细胞壁的细胞质连接（共质体 运动），通过细胞壁连续体（质外体运动），或 两者的结合。 这些研究的结果将具有长期的实际意义 对作物生产力具有重要价值， 对病毒，昆虫，支原体， 和其他寄生虫，以及杀虫剂和生长的运动 栽培植物中的调节物质。 大麦，玉米， 大豆是重要的经济作物，

Two broad aims of this research are to determine (1) the pathways followed by sugars manufactured in the photosynthesizing cells (mesophyll cells) of the leaf to the food-conducting cells (sieve-tube members) of the leaf veins, and (2) the sites at which the sugars are actively secreted, or loaded, and unloaded in mature (source) and immature (sink) leaves, respectively. Detailed structural studies, with light and electron microscopes, are complemented by experimental studies, including localization of 14C-labeled sugars within the leaf by microautoradiography; plasmolysis studies designed to determine the solute (primarily sugar) concentrations of the various cell types; and the use of fluorescent dyes to determine whether substances move from cell to cell via cytoplasmic connection in their walls (symplastic movement), via the cell wall continuum (apoplastic movement), or a combination of the two. The results of these studies will be of long-term practical importance in relation to crop productivity and will be of great value to investigators interested in relations of viruses, insects, mycoplasmas, and other parasites, and in the movement of insecticides and growth regulating substances in cultivated plants. Barley, maize, and soybean, species to be studied, are economically important plants.