The regulation of plant cell growth: A bio-electromechanochemical model

A dynamic model was developed describing the bio-electromechanochemical changes (Bemchem model) of a plant cell which is concomitantly elongating and changing its surface by cell wall synthesis. The model takes into account the interdependent relationships between mechanical, electrical and biochemical events at the supramolecular-cellular level of organization (cytoplasm-plasmalemma and cell wall). The model simulates, qualitatively and quantitatively, the auxin-induced membrane hyperpolarization. The transcellular MP is coupled to energetic metabolism through its active, i.e. electrogenic (H⁺ pump), component. Model results predict that the value and time-dependent behavior of the MP influences cellulose synthesis both qualitatively and quantitatively. The model also predicts that cell wall synthesis could be elicited prior to an exponential elongation of the cell. The electromechanical changes sensed by the plasma membrane appear to be earlier processes, conditioning future biochemical events, such as cellulose synthesis, associated to plant cell differentiation (secondary cell wall formation).