Light‐ and Clock‐Controlled Leaflet Movements in Samanea saman*: A Physiological, Biophysical and Biochemical Analysis**

Abstract
Leaflet movements in the legume Samanea saman are under joint control by light and a circadian oscillator. The movements are driven by massive fluxes of K+, Cl, and H+ through pulvinar motor cell membranes. Light and the oscillator affect leaflet movements by altering the activity of ion transport systems. Some effects of light on ion transport may be mediated by the phosphatidylinositol (PI) cycle, since brief irradiation of the pulvinus with white light accelerates PI turnover.