Agronomy Department, Institute of Agriculture, University of Western Australia, Nedlands, Western Australia 6009.
Plant Physiol. 1970 Aug;46(2):259-62. doi: 10.1104/pp.46.2.259.
Zea mays was exposed to solutions of low water potentials by addition of ethylene glycol or mannitol. Intact seedlings were treated for 1 hr at potentials between -10 and -20 atmospheres and then returned to high water potentials. Subsequent root extension was slow after mannitol treatment, but rapid when ethylene glycol had been used as the osmoticum. Cellular activity of excised roots was also affected much less by ethylene glycol than by mannitol. Processes studied included respiration, glucose uptake, and synthesis of methanol-insoluble compounds. These differences in response to various osmotica applied both during and after treatment at low water potentials.Ethylene glycol penetrated the tissues much more rapidly than mannitol. Rapid penetration of the osmoticum would minimize turgor loss and plasmolysis. Thus, the data suggest that adverse effects were induced by water loss or structural changes, or both, during plasmolysis, rather than by low water potentials, demonstrating the crucial importance of osmotic adjustment.
玉米幼苗经乙二醇或甘露醇溶液处理后，可暴露于水势较低的溶液中。将完整的幼苗在-10 至-20 大气压的水势下处理 1 小时，然后恢复到高水势。甘露醇处理后，根的延伸缓慢，但使用乙二醇作为渗透剂时，根的延伸迅速。离体根的细胞活性也受乙二醇的影响远小于甘露醇。研究的过程包括呼吸作用、葡萄糖摄取和甲醇不溶性化合物的合成。这些对不同渗透物的反应差异，无论是在低水势处理期间还是之后都有体现。乙二醇比甘露醇更快地渗透到组织中。渗透物的快速渗透将最大限度地减少膨压损失和质壁分离。因此，数据表明，在质壁分离过程中，是由水分流失或结构变化，或两者共同引起的不良反应，而不是低水势引起的，这表明渗透调节的至关重要性。
