Scientists have known for some time that plants can conduct electricity. In fact, researchers at the Massachusetts Institute of Technology found that plants can pack up to 200 millivolts of electrical power.
Plant and fruit cells internally are made up of various kinds of dissolved minerals in a liquid form constituting the cell sap. This cell sap is present inside all plants, vegetables and fruits, and is ideally suited to conduct electrons and also generate electricity (though quite feebly). The sugars in the plant produce an energy source ATP/ NADH+ which triggers electrical currents in the cells' mitochondria.