Effect of infection by Phytophthora infestans and treatment with zoosporial water-insoluble component on leakage of 86Rb+ from potato tuber cells

Potato tuber disks, 15mm in diameter and 1mm thick, Which had absorbed 86RbCl, Were inoculated by incompatible and compatible races of Phytopthora infestans. At intervals, leakages of 86Rb+ from the infected disks were determined. The leakage of 86Rb+ was accelerated by infection with the incompatible race in an early stage of infection, at which hypersensitive death of the infected cells had not yet occurred. The acceleration rate was not great, but statistically significant. There was, on the contrary, no difference in leakage of 86Rb+ between control and the disks infected by the compatible race. 86Rb+-labelled disks were immersed for 10min in a suspension of water-insoluble zoosporial component (C-fr, sugar content, 30μg/ml). At intervals, leakages of 86Rb+ from the treated disks were determined. The results showed that C-frs of both the compatible and incompatible races reduced greatly the release of 86Rb+. Effects of infection opposite to that of C-fr suggested that the latter, as it is, may not be the very cause of the hypersensitive response in potato late blight, or that C-fr may not induce the proper response of hypersensitivity, when the disks were treated by the method used in the present experiments.