Abstract The analysis of the electrophysiological activity of plants permits a real-time information of the plant status (e.g. light availability and water stress). However, even though it is clear that the role of the electrical signals in plant is crucial, especially in processes involving the propagation of rapid signals, a systematic approach for the interpretation of the electrical patterns is still missing. In this work a multi-electrodes approach has been applied to study the electrical signals in olive trees plants subjected to three different level of water stress. In particular, by using specific water irrigation regimes, a control group, a mid/mild stressed group and a high stressed group have been monitored and subsequently subjected to a long period of prolonged drought stress. Physiological parameters and electrical activity have been continuously monitored for the whole experiment to highlight any correlation between the electric signal and the water stress. Our results showed that it has been possible to differentiate the electric signals related to drought conditions of different intensity (i.e. control, mild and high). In particular we have found that the average daily relative electrical resistance change, the opposite of the electrical conductance, is directly related to the drought stress whilst the signal variance increases during the period of main water stress. Additionally, a proposed signal classification system has been successfully able to detect the absence/presence of stress and to effectively recognize daily class samples (93 % control, 76 % mild and 80 % high). The set-up could provide a useful tool for monitoring water conditions in plants and has several potential applications for sensor and automatic system in greenhouse or field able to monitor directly the plant water status.

中文翻译：

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与橄榄树水分胁迫条件相关的茎电特性

摘要 植物电生理活动的分析允许实时了解植物状态（例如光照和水分胁迫）。然而，尽管很明显电信号在植物中的作用至关重要，尤其是在涉及快速信号传播的过程中，但仍然缺少解释电模式的系统方法。在这项工作中，已应用多电极方法来研究遭受三种不同水分胁迫的橄榄树植物的电信号。特别是，通过使用特定的水灌溉制度，控制组、中/轻度压力组和高压力组已被监测并随后经受长时间的长期干旱压力。在整个实验中持续监测生理参数和电活动，以突出电信号与水分胁迫之间的任何相关性。我们的结果表明，可以区分与不同强度（即控制、轻度和高）干旱条件相关的电信号。特别是我们发现平均每日相对电阻变化，与电导相反，与干旱胁迫直接相关，而信号方差在主要水分胁迫期间增加。此外，建议的信号分类系统已成功地能够检测压力的缺失/存在并有效识别日常类样本（93% 控制、76% 轻度和 80% 高）。