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.

Effect of the lithium chloride on the leaf movements of Cassia fasciculata.

LiCl inhibits the nyctinastic closure of folioles of excised leaves and enhances their opening, if there are 3 h before the light is switched off or on; the minimal concentration for significant effects on closure is 3·10(-4) M, and on opening 3·10(-3). The use of chlorides of other cations and other Li salts showed specificity of the lithium for the closure movement, the effect being reversed by KCl and NaCl. For the opening movement the Li effect is less specific. These results are compared to those obtained in other phenomena.