Vertical and horizontal electric fields stimulate growth and physiological responses in lettuce

An electric field, a field of electric force surrounding a charged particle, affects the growth, development, morphology, and physiological responses of plants. Previous studies have reported the effects of electric fields on plants, but further investigation is required to understand better how these fields influence plants. Thus, we aimed to explore the effects of both vertical and horizontal electric fields on the growth and physiological responses of lettuce ( Lactuca sativa ) in controlled environmental conditions. When treated 10-day-old lettuce seedlings with 5 kV/m of vertical or horizontal electrostatic fields for 28 days, the fresh weights of shoots and roots increased. The morphological changes in the leaves differed depending on the direction of the electric field. In addition, electric fields enhanced the uptake mineral content of the plants that is transported into different plant organs and tend to improve their transpiration rate and stomatal conductance. A vertical electric field accelerated sap flow through stems. The rate of the G1 phase of the cell cycle was highest following electric field treatments. Microscopy observations of stomatal size and epidermal cell size supported the notion that mineral uptake was enhanced by the increased transpiration rate and expanded leaf area. Our results indicate that electric fields have positive effects on lettuce growth and physiological responses and that the growth of lettuce is altered by electric fields from different directions. We propose that electric fields could be utilized as an environmental factor to maximize plant productivity and modulate plant responses.