Plasmolysis, Plasmodesmata, and the Electrical Coupling of Oat Coleoptile Cells

Abstract

Ultrastructural studies on oat coleoptile parenchyma cells (Avena sativa L. cv. Victory) reveal that severe plasmolysis either breaks plasmodesmatal connections or leaves the protoplasts still connected via strands of cytoplasm (Hechtian strands). Plasmolysis also induces the formation of callose around the plasmodesmata. The callose remains for several hours after recovery of the cells to full turgor. Immediately following recovery of turgor, intercellular electrical coupling cannot be detected. However, during the next 6 h, some degree of coupling is restored. These results indicate that, while plasmolysis does not necessarily break all plasmodesmatal connections, the treatment probably does disrupt them sufficiently to interfere, at least temporarily, with symplastic transport.