Effects of static magnetic field on the ultradian lateral leaflet movement rhythm in Desmodium gyrans

Abstract

The rhythmic leaflet movements of the plant Desmodium gyrans (L.f.) DC slow down in the presence of a static magnetic field. The leaflet positions were digitally retrieved from sequential CCD camera images of the moving leaflets. The experiments were performed under constant light (ca. 500 lux) and temperature (about 20 °C) conditions. The period of the leaflet was then around 5 min. Leaflets moving up and down in a magnetic field of approximately 50 mT flux density increased the period by about 10% due to a slower motion in the 'up' position. Since during this position a rapid change of the extracellular potentials of the pulvinus occurs, it is proposed that the effects are mediated via the electric processes in the pulvinus tissue.