Physiological and Cytological Similarities between Disease Resistance and Cellular Incompatibility Responses

Excised pea pods responded similarly to both the invasion of plant pathogenic fungi and the presence of bean tissue, bean pollen, and mouse tumor cells by synthesizing pisatin and by developing a characteristic yellow-green fluorescence. Both responses were dependent on RNA and protein synthesis. Conversely, the foreign pollen and incompatible fungi were sensitive to the pea pod tissue and were subject to abnormal development.