Plant electrome: the electrical dimension of plant life

The sessile lifestyle of plants exposes them to many challenges that must be overcome to ensure their survival. Despite their apparent lack of movement and behaviour, plants are very active organisms that constantly respond to external cues and internal signals, making fine tunings at the metabolic, cellular and tissue levels. To accomplish this, plants largely rely on their relationship between phenotypic plasticity and cognitive abilities, which requires an information (or signalling) system. This information system is composed of many different signals, and among them are the electrical ones. Besides, in plants, there are many electrical activities that are not necessarily considered electrical signals. However, the sum of all electrical activity of a plant, considering all levels of organization, engenders the electrical dimension of their life. This dimension of life that encompasses all the living beings has recently been named “electrome”, in analogy with the other ‘omics’ from system biology approach. In the present review, we will explore this concept to describe the plant electrical activities. Furthermore, some basic aspects that are underlying the plant electrome will be presented, including the principles of biophysics that sustain the electrical activity of the cells. Moreover, some examples of electrical activities and signals that are vital to the plants will be exposed. Then, our most relevant and recent breakthroughs about plant electrome dynamics under different environmental conditions will be presented. Finally, some considerations about the possible involvement of the electrome plasticity and cognition features associated with the adaptive behaviour of plants will be discussed.