School of Biological Sciences, University of Sussex, Brighton, UK.
Planta. 1971 Sep;100(3):200-7. doi: 10.1007/BF00387036.
Exudate can be obtained from incisions made in the bark of the stem of actively growing Ricinus plants. (14)C-labelled assimilates from a fed leaf are rapidly detected in the exudate. This movement was both acropetal and basipetal from the fed leaf, at rates of over 100 cm h(-1). Estimated rates within intact plants were 80-84 cm h(-1).In contrast with xylem sap obtained from the same plant, the exudate obtained had an alkaline pH (8.2), a high dry matter content (10-12.5%), high sugar content (8-10%) which was predominantly sucrose; high potassium content (60-80 mM) and low calcium content (0.5-1.0 mM).It is concluded, on the basis of the present evidence, that the exudate is a true sample of the sieve tube sap undergoing translocation.
渗出物可从生长活跃的蓖麻茎的树皮切口获得。在渗出物中迅速检测到来自被喂养叶片的 (14)C 标记同化产物。这种运动从被喂养叶片向顶和向基均有发生，速度超过 100 cm h(-1)。在完整植物中的估计速度为 80-84 cm h(-1)。与从同一植物获得的木质部汁液相比，获得的渗出物具有碱性 pH（8.2）、高干物质含量（10-12.5%）、高糖含量（8-10%，主要是蔗糖）、高钾含量（60-80 mM）和低钙含量（0.5-1.0 mM）。根据目前的证据，可以得出结论，渗出物是正在进行转运的筛管汁液的真实样本。
