Effect of Vanadate on Rhythmic Leaflet Movement in Albizzia Julibrissin

Vanadate (Na(3)VO(4)) selectively and reversibly affects the rhythmic movement of Albizzia julibrissin leaflets. Leaflets floated on 1 millimolar vanadate open at the same rate or more rapidly than controls, but closure is inhibited. After 6 to 24 hours incubation, the inhibition can be reversed by a 24-to 48-hour period on water or control buffer. Recovery is complete in light-dark cycles, and it is almost complete under free-running conditions (prolonged darkness). Leaflets floated on 10 millimolar vanadate do not open in darkness, but they open at a reduced rate in light. Concentrations of 100 micromolar or less are ineffective.