Green plants: electrochemical interfaces

The most rapid methods of long distance communication between plant tissues and organs are bioelectrochemical signals. The action potential propagates rapidly throughout the plant along electrified interfaces. A potential pathway for transmission of this electrical signal might be the phloem sieve-tube system since it represents a continuum of plasma membranes. A phloem is an electrical conductor of bioelectrochemical impulses over long distances. At the cellular level in plants, electrical potentials exist across membranes, and thus between cellular compartments, as well as within specific compartments. Electrochemical phenomena are primary, and then deep cytophysiological reactions occur. Possible effects of the electric double layer of the Earth on the electrical activity of plants are discussed. Effects of uncouplers and acid rains on green plants are studied. Uncoupler carbonyl cyanide-p-trifluoromethoxyphenyl hydrazone (FCCP) induces ultra fast action potentials and decreases the resting potential in a soybean. The speed of the propagation of action potentials in a soybean induced by FCCP reaches up to 40 m s−1. The duration of single action potentials after treatment by FCCP was 0.0003 s. Adding FCCP to soil decreases the resting potential to zero level. The automatic measurements of the electrical potential difference can be effectively used in bioelectrochemistry, environmental plant electrophysiology, for the study of molecular mechanisms of transport processes and the influence of external stimuli on plants.