Different root growth patterns in tomato seedlings grown hydroponically under an electric field

Electric fields can determine changes at morphological and physiological levels in plants. In this study, seedlings of Solanum lycopersicum L., grown hydroponically in a floating system, were exposed to a DC 12.0 V m–1 electric field (EF). Root morphology was strongly affected by the electric field applied and a significant variation in root growth rate was observed along the gradient. The tomato plants grown on the hand of the positive electrode showed a pronounced length, root hairs’ development and root branching, compared to the plants grown at the central area of the container and on the hand of the negative electrode. Root growth of the control plants not exposed to the EF resembled that of EF-exposed plants taken in the central area. Hypotheses according to which the different growth patterns observed could be related to a chemiosmotic-induced activity and/or the distribution of plasma membrane carriers are discussed. In conclusion, the root growth was affected by the positions under application of EF. The results point to a possibility of applying electric fields for controlling tomato root growth.