Effects of Salicylic and Acetylsalicylic Acids on the Scotonastic and Photonastic Leaflet Movements of Cassia fasciculata.

Salicylic and acetylsalicylic acids applied on excised leaves of Cassia fasciculata modify the dark-induced (scotonastic) and light-induced (photonastic) leaflet movements. They inhibit the scotonastic movements in a dose-dependent manner from 1 x 10(-4) to 1 x 10(-3) molar and they promote the photonastic movements at an optimum concentration of 5 x 10(-4) molar. These results suggest that these phenolic compounds do not act specifically on the K(+) uptake, which was shown to be inhibited by their action on other materials.