Permeability Changes in Tissues and Other Effects of Cell-separating Solutions from Soft Rots Caused by Corticium praticola and Erwinia atroseptica

Cell-free extracts from soft rots of potato tubers caused byErwinia atroseptica and Corticium praticola readily caused cellseparation and loss of electrolytes in discs of potato tubers.Both were most rapid at pH and Ca⁺⁺ ion concentration optimalfor the activity of a pectate trans-climinase in the E. atrosepticaextract and a pectate polygalacturonase in the C. praticolarot extract. Permeability changes and killing of protoplastsbut not cell separation were delayed when solutes at plasmolysingconcentrations were added to the solutions of the cell-separatingenzymes. The role of these enzymes in the permeability changesand killing of protoplasts is discussed.