Webb J A
Biology Department, Carleton University, Ottawa, Ontario, Canada.
Plant Physiol. 1967 Jun;42(6):881-5. doi: 10.1104/pp.42.6.881.
A study has been made of the temperature control of translocation localized to regions of the stem, petiole and hypocotyl of Cucurbita melopepo. The basipetal and acropetal movement of translocated (14)C-labeled compounds in the phloem tissue, measured over a 45-minute period, was almost completely inhibited at 0 degrees . At 10 degrees a partial inhibition occurred while an extremely variable degree of inhibition occurred at 15 degrees . Above 15 degrees to 35 degrees temperature ceased to be a limiting factor in the movement of (14)C-labeled compounds. At 45 degrees partial inhibition was observed while at 55 degrees there was an almost complete cessation. The localized temperature treatment of the plant parts did not disturb the rate of (14)CO(2) assimilation or the export of (14)C compounds by the leaf blade. Translocated compounds unable to pass a temperature inhibited zone were diverted toward other importing regions of the plant. The similarity of the translocation response to temperature change in the various organs of the plant indicated a uniform mechanism throughout the plant controlling movement of the major proportion of the translocated compounds. The temperature characteristics of the mechanism were found to closely parallel those of protoplasmic streaming in chill-sensitive plants.
对南瓜茎、叶柄和下胚轴部位的物质运输温度调控进行了一项研究。在45分钟内测量韧皮部组织中经（14）C标记的转运化合物的向基运输和向顶运输，在0摄氏度时几乎完全受到抑制。在10摄氏度时出现部分抑制，而在15摄氏度时抑制程度变化极大。高于15摄氏度至35摄氏度时，温度不再是（14）C标记化合物运输的限制因素。在45摄氏度时观察到部分抑制，而在55摄氏度时几乎完全停止。对植物各部位进行局部温度处理并未干扰（14）CO₂同化速率或叶片输出（14）C化合物的过程。无法通过温度抑制区的转运化合物会转向植物的其他输入区域。植物各器官中物质运输对温度变化的反应相似，表明整个植物存在一种统一机制来控制大部分转运化合物的移动。发现该机制的温度特性与冷敏感植物中胞质环流的温度特性密切相似。
