A novel class of fast electrical events recorded by electrodes implanted in tomato shoots

An unfamiliar class of electrical events with rapid rise and slow decay has been identified in tomato (Lycopersicon esculentum Mill.) plants impaled b y metal electrodes. Rise-times of these extracellularly detected events can be 200 mus or less, while fall-times can require hundreds of milliseconds. In excised tomato shoots, these events are associated with the imposition of water stress. The hypothesized origin of these events is the fracture of water columns in the xylem and the triboelectrification that occurs as the ends of the columns snap apart.