University of Poitiers, UFR Sciences Fondamentales et Appliquées, UMR CNRS 7267 Laboratoire EBI Ecologie et Biologie des Interactions, Equipe SEVE Sucres & Echanges Végétaux Environnement 3, rue Jacques Fort, Bât. B31, TSA 51106, 86073, Poitiers Cedex 9, France.
University of Bourgogne Franche-Comté, Laboratoire de Chrono-Environnement, UMR CNRS 6249 UsC INRA, 16 route de Gray, 25000, Besançon, France.
Plant Physiol Biochem. 2019 Sep;142:528-535. doi: 10.1016/j.plaphy.2019.08.006. Epub 2019 Aug 12.
Tryptophan at concentrations higher than 0.1 mM, triggered characteristic early physiological effects such as rapid (within 5 min) dose-dependent membrane hyperpolarization in Mimosa pudica motor cells and modification of the time course of the spontaneous proton efflux monitored in the incubation medium of pulvinar tissues. The rapid modifications of the leaf turgor-mediated movements seen on the primary pulvini of M. pudica following a shock and on Cassia fasciculata leaflets during a transition from light to darkness indicate that tryptophan disturbed the ionic migrations involved in the electrophysiological events and in the osmocontractile reaction of the motor cells. These reactions were specific to tryptophan compared to those induced by serine and 5-hydroxytryptophan. The tryptophan mode of action cannot be linked to a direct modification of the plasma membrane H-ATPase activity as monitored on purified pulvinar plasma membrane vesicles. The tryptophan metabolism-linked products tryptamine and indole also inhibited the motile reactions, activated in a continuous manner the H secretion of pulvinar tissues and showed properties of a protonophore and an ATPase activity inhibitor on plasma membrane vesicles, respectively. The specific behavior of tryptophan in the reaction studies here is discussed in light of the previously reported action of phytohormones.
色氨酸在浓度高于 0.1mM 时，会引发含羞草运动细胞的快速（5 分钟内）、剂量依赖性的膜超极化等典型的早期生理效应，以及在叶枕组织孵育介质中监测到的自发质子外流的时间进程的改变。在含羞草的初生叶枕受到电击后和在决明子叶片从光到暗的转变过程中，叶子膨压介导的运动的快速变化表明色氨酸扰乱了参与电生理事件和运动细胞渗透收缩反应的离子迁移。与丝氨酸和 5-羟色氨酸诱导的反应相比，这些反应是色氨酸特有的。色氨酸的作用模式不能与在纯化的叶枕质膜小泡上监测到的质膜 H+-ATP 酶活性的直接修饰联系起来。色氨酸代谢相关产物色胺和吲哚也抑制了运动反应，持续激活叶枕组织的 H+分泌，并分别显示出质子载体和质膜小泡上 ATP 酶活性抑制剂的特性。根据先前报道的植物激素的作用，本文讨论了色氨酸在反应研究中的特殊行为。
