Abstract

The plasma membrane H+-ATPase (PM H+-ATPase) is a critical regulator of cellular homeostasis and is central to the plant cell's ability to sense and respond to environmental stresses, including low temperature. This study presents a theoretical analysis, employing a mathematical model of plant electrogenesis, to investigate the influence of fluctuations in PM H+-ATPase activity on the low-temperature-induced electrical responses in a plant cell. The objective was to elucidate the biophysical mechanisms by which dynamic changes in this primary proton pump contribute to the initiation and propagation of electrical signals, such as action potentials or variation potentials, under chilling stress. The model incorporates the electrogenic activity of the PM H+-ATPase, the passive ion fluxes across the membrane, and the temperature-dependent changes in membrane properties. Key findings indicate that even minor, localized fluctuations in H+-ATPase activity can significantly modulate the membrane potential, leading to a shift in the threshold for electrical signal generation. Specifically, a reduction in H+-ATPase activity, potentially due to cold-induced membrane rigidification, results in depolarization, which is a hallmark of the cold-induced electrical response. This theoretical framework provides crucial insights into the signal transduction pathways linking membrane biochemistry to whole-cell electrical signaling, highlighting the PM H+-ATPase as a key nexus in the plant's cold-acclimation response.