Rhythmic Leaflet Movement in Albizzia julibrissin: Effect of Electrolytes and Temperature Alteration 1

AUTOR(ES)

Satter, Ruth L.

RESUMO

The rhythmic movement of darkened Albizzia leaflets is accompanied by K+ flux in pulvinule motor cells whose turgor changes control opening and closing. The azide-sensitive open phase is promoted by an increase in temperature from 16 to 33C (Q10 = 3), implying active transport of K+ ions during this period. The azide-insensitive closed phase is less temperature-sensitive and has a Q10 less than 1, implying diffusion or some other physical process as the predominant pathway of K+ flux at this time. Thus rhythmic leaflet movement is probably due to oscillation in active K+ transport or membrane permeability or both. External electrolytes (0. 1 n) alter leaflet angle during the open, but not the closed, phase of the rhythm. All chlorides except NH4+ promote opening, with divalent more effective than monovalent ions. Some anions promote and others inhibit opening; activity is not correlated with charge. It is likely that electrolytes alter leaflet movement by altering K+ flux, accomplishing this by interacting with key macromolecules in motor cell membranes.

Documentos Relacionados

• Effect of Vanadate on Rhythmic Leaflet Movement in Albizzia Julibrissin1
• Phytochrome-controlled Nyctinasty in Albizzia julibrissin: IV. Auxin Effects on Leaflet Movement and K Flux 1
• Phytochrome-controlled Nyctinasty in Albizzia julibrissin: III. Interactions between an Endogenous Rhythm and Phytochrome in Control of Potassium Flux and Leaflet Movement 1
• Potassium-linked Chloride Fluxes during Rhythmic Leaf Movement of Albizzia julibrissin1
• Quantifying Rhythmic Movements of Albizzia julibrissin Pinnules 1