Thermal petiole wounding triggers trap closure in Dionaea muscipula

The Venus flytrap (Dionaea muscipula Ellis) is a carnivorous plant that captures invertebrates using an electrically excitable trap mechanism. Invertebrates stimulate trigger hairs, initiating action potentials (APs) that drive rapid closure. Trap lobes are electrically isolated from one another by non-excitable petioles. We examined thermal wounding to leaf petiole's ability to produce detectable electrical activity in the isolated trap and if wounding stimulation is sufficient to trigger closure. Using a within-subject design across 15 mature plants, we compared trap-recorded electrical signals following trigger hair (TH) stimulation and petiole branding with a heated soldering iron. Primary spike morphology did not differ significantly between treatment groups for either Spike/Baseline Ratio or Depolarization Fraction. Within-Brands primary-to-secondary Spike/Baseline Ratios differed significantly consistent with non-regenerative signal attenuation rather than canonical AP propagation from the petiole. Differences are consistent with thermal petiole wounding disrupting xylem continuity and generating a hydraulic pressure transient that initiates trap-derived APs through the trap's own excitation machinery. The trap's closure threshold is accessible via sufficiently large, likely non-electrical, systemic perturbation.