The Influence of Salts on Protoplasmic Streaming generated by Light in Subepidermal Cells of Vallisneria Leaves

Through exposure protoplasmic streaming appears in subepidermal cells of leaf lengths of Vallisneria pretreated with water (light reaction). The light reaction is not forthcoming when before exposure the leaf lengths have been treated for an hour with 0.001 M concentrations of KC1, KNOs, KHCOa, K2SO,„ KH2P04, CaS04 and RbCl. The inhibition of the light reaction under the influence of these salts is reversible. By Na, Li, Mg, Sr, La and Co(NH3)6-chloride, A1 sulphate and KCNS streaming is already induced in the dark in different degrees; the light reaction is not inhibited or only little. Under the influence of Co(NH3)6 and La the streaming percentage decreases with the time; a light reaction does not occur: these salts cause damage. The effects of salts are mainly cation effects. The inhibition of the light reaction by KC1 affects the initiation of the streaming, not the streaming as such. Modifications in the viscosity of the plasm, as determined from experiments with centrifugal force are probably immaterial for the initiation of protoplasmic streaming. It has been assumed that salts modify the properties of contractile proteins directly or influence the energetic system of protoplasmic streaming too.