ABSTRACT

The circadian clock regulates a wide range of physiological processes in plants. Here we showed the circadian variations of the electrical signals in Broussonetia papyrifera L. and Morus alba L. in a natural state, which were analyzed using the day–night cycle method. The circadian characteristics of different plant electrical signals were compared by constructing a coupling model for the circadian rhythm of plant electrical signals. The electrical signal sensor had two electrode plates, which were fixed on the two ends of the splint, leaves could then be clamped and measured. The clamping force between the two electrode plates was uniform, which enabled continuous and nondestructive measurements. The results showed that an electric cyclic behavior was observed (circadian cycle) with the circadian variation in the plants within 24 h. Both the resistance (R) and the impedance (Z) increased firstly in the early morning and then decreased subsequently, while the capacitance (C) showed an opposite variation. Under different weather conditions, plant electrical signals showed periodic changes when the temperature and light intensity in the environment slightly changed within the physiological tolerance of plant. This indicated that the circadian clock of plant electrical signals could be maintained endogenously. The variation curves of plant electrical signals as time increased were fitted using the sine equation. The characteristic parameters of circadian rhythm of plant electrical signals were obtained. We found that although all plant electrical signals exhibited electric cyclic behavior, but the characteristics of circadian rhythms of electrical signals were different. This study provided a scientific basic for precisely monitoring plant electrical signals, and a reference for revealing circadian rhythms of plant electrical signals and their occurrence rules.

摘要

生物钟调节植物中广泛的生理过程。在这里，我们展示了Broussonetia papyifera L. 和Morus alba中电信号的昼夜节律变化L. 处于自然状态，采用昼夜循环法进行分析。通过构建植物电信号昼夜节律耦合模型，比较了不同植物电信号的昼夜节律特征。电信号传感器有两个电极板，固定在夹板的两端，然后可以夹住叶片进行测量。两个电极板之间的夹持力是均匀的，这使得连续和无损测量成为可能。结果表明，随着植物在 24 小时内的昼夜节律变化，观察到电循环行为（昼夜循环）。电阻（R）和阻抗（Z）在清晨均呈先上升后下降的趋势，而电容（C）则呈现相反的变化。在不同的天气条件下，当环境中的温度和光照强度在植物生理耐受范围内发生轻微变化时，植物电信号呈现周期性变化。这表明植物电信号的生物钟可以内源性维持。使用正弦方程拟合植物电信号随时间增加的变化曲线。获得了植物电信号昼夜节律的特征参数。我们发现，虽然所有植物电信号都表现出电循环行为，但电信号的昼夜节律特征不同。本研究为精确监测植物电信号提供了科学基础，