No abstract

Electrical activity plays an important role in plant life; in particular, electrical responses can participate in the reception of the action of stressors (local electrical responses and oscillations) and signal transduction into unstimulated parts of the plant (action potential, variation potential and system potential). Understanding the mechanisms of electrical responses and subsequent changes in physiological processes and the prediction of plant responses to stressors requires the elaboration of mathematical models of electrical activity in plant organisms. Our review describes approaches to the simulation of plant electrogenesis and summarizes current models of electrical activity in these organisms. It is shown that there are numerous models of the generation of electrical responses, which are based on various descriptions (from modifications of the classical Hodgkin-Huxley model to detailed models, which consider ion transporters, regulatory processes, buffers, etc.). A moderate number of works simulate the propagation of electrical signals using equivalent electrical circuits, systems of excitable elements with local electrical coupling and descriptions of chemical signal propagation. The transmission of signals from a plasma membrane to intracellular compartments (endoplasmic reticulum, vacuole) during the generation of electrical responses is much less modelled. Finally, only a few works simulate plant physiological changes that are connected with electrical responses or investigate the inverse problem: reconstruction of the type and parameters of stimuli through the analysis of electrical responses. In the conclusion of the review, we discuss future perspectives on the simulation of electrical activity in plants.

No abstract

Variation potential (VP), a propagating electrical signal unique to plants, induces a number of changes in many physiological processes. However, the mechanisms of its generation and propagation are still under discussion and require experimental and theoretical analysis, including VP simulations. The mathematical model for VP formation in plants has been worked out and is based on our previous description of electrophysiological processes in higher plant cells, including plasma membrane ion transport systems (K(+), Cl(-) and Ca(2+) channels, H(+) and Ca(2+)-ATPase, 2H(+)/Cl(-) symporter and H(+)/K(+) antiporter) and their regulation, ion concentration changes in cells and extracellular spaces and buffers in cytoplasm and apoplast. In addition, the VP model takes into account wound substance diffusion, which is described by a one-dimensional diffusion equation, and ligand-gated Ca(2+) channels, which are activated by this substance. The VP model simulates the experimental dependence of amplitude, velocity and shape of VP on the distance from the wounding site and describes the influence of metabolic inhibitors, divalent cation chelators and anion channel blockers on the generation of this electrical reaction, as shown in experiments. Thus, our model favorably simulates VP in plants and theoretically supports the role of wound substance diffusion and Ca(2+) influx in VP development.