The dielectric effect enforced on charged ions and dipolar molecules by the oscillating electric field of microwaves may influence electric signaling in plants. In the present study, the exposure of Nicotiana benthamiana plants to continuous wave 2.45 GHz microwave radiation with 1.9 - 2.1 W m-2 power density significantly reduced the amplitude of leaf burning-induced variation potential along the plant stem. The change in amplitude of the variation potential occurred mainly because of a significant reduction of the depolarization rate. This effect was not observed during the post-microwave exposure period. The unique characteristics observed in the variation potentials were also observed under microwave exposure, suggesting unaffected information delivery to distant locations or unaffected transport of specific chemicals generated by the injury.
Keywords: Abiotic stress; electromagnetic radiation; non-thermal effect; plant signaling; wounding.