DOCUMENTATION. “The transmission of both, APs and VPs, occurs via the phloem over long distances and via plasmodesmata over short distances from cell to cell. Regarding physiological functions of electrical signals, numerous examples exist. They regulate rapid leaf movements in order to catch insects and for instance, affect nutrient uptake, gene expression and phloem transport.” (APs = action potentials; VPs = variation potentials).
http://www.sciencedirect.com/science/article/pii/S0098847214001634