Engelmann W, Antkowiak B
Physiologische Okologie der Pflanzen, Institut für Botanik, Universität Tübingen, Germany.
Chronobiol Int. 1998 Jul;15(4):293-307. doi: 10.3109/07420529808998691.
The leaves of Desmodium gyrans (L.F.) DC show circadian movements in the terminal and ultradian movements of the lateral leaflets. The movements are due to swelling and shrinking of motor cells in special organs. The anatomy of these pulvini is described for the lateral leaflets. Data from electrophysiological recordings using microelectrodes inserted into the lateral pulvini, together with treatments that affect the proton pumps and ion channels, have been used to develop a physiological model of the ultradian leaflet movement. It explains the oscillations in the motor cells as being due to a change between a pump state and depolarization. During the pump state, ions are taken up, causing water influx and swelling of the motor cells. Depolarization causes loss of ions and water efflux (the motor cells shrink). The roles of calcium and the phosphatidyl inositol signal chain are discussed on the basis of experiments using chemical agents that affect these processes. Since calcium oscillations are known to occur in organisms in both time and space, an attempt has been made to simulate the situation in Desmodium pulvini by a model of specially coupled oscillators. Effects of different other treatments of the lateral pulvini are discussed. Oscillations in the minute range seem to be more common and some might be related to turgor regulation and ion uptake comparable to the situation in Desmodium. The ultradian control of the lateral pulvini and the circadian control of the terminal pulvini are apparently based on different mechanisms.
舞草（Desmodium gyrans (L.F.) DC）的叶片表现出顶生叶片的昼夜节律运动和侧生小叶的超昼夜运动。这些运动是由于特殊器官中运动细胞的膨胀和收缩引起的。本文描述了侧生小叶中这些叶枕的解剖结构。利用插入侧生叶枕的微电极进行电生理记录的数据，以及影响质子泵和离子通道的处理方法，建立了超昼夜小叶运动的生理模型。该模型解释了运动细胞中的振荡是由于泵状态和去极化之间的变化所致。在泵状态下，离子被吸收，导致水流入和运动细胞膨胀。去极化导致离子流失和水流出（运动细胞收缩）。基于使用影响这些过程的化学试剂的实验，讨论了钙和磷脂酰肌醇信号链的作用。由于已知钙振荡在生物体中在时间和空间上都会发生，因此尝试通过特殊耦合振荡器模型来模拟舞草叶枕中的情况。讨论了侧生叶枕的不同其他处理的效果。分钟范围内的振荡似乎更为常见，其中一些可能与膨压调节和离子吸收有关，类似于舞草中的情况。侧生叶枕的超昼夜控制和顶生叶枕的昼夜控制显然基于不同的机制。
