Changes in activity of H<sup>+</sup>-ATPase of plasma membrane as a link between forming electrical signals and induction of photosynthetic responses in higher plants

Abstract

Action of numerous adverse environmental factors on higher plants is spatially-heterogenous; it means that induction of a systemic adaptive response requires generation and propagation stress signals. Electrical signals (ESs) induced by local action of stressors include action potential, variation potential, and system potential and participate in forming fast physiological changes at the level of the whole plant, including photosynthetic responses. Generation of these ESs is accompanied by changes in activity of H+-ATPase which is the main system of electrogenic proton transport across the plasma membrane. Literature data show that the changes in H+-ATPase activity and related changes in intra- and extracellular pH play a key role in ESs-induced photosynthetic inactivation in non-irritated parts of plants. This inactivation is caused by both suppression of CO2 flux into mesophyll cells in leaves, which can be induced by the apoplast alkalization and, probably, cytoplasm acidification, and direct influence of acidification of stroma and lumen of chloroplasts on photosynthetic light and, probably, dark reactions. Result of the ESs-induced photosynthetic inactivation is increasing tolerance of photosynthetic machinery to action of adverse factors and probability of survive of plants.