VIEW ARTICLE

Physiology and Biochemistry

Effect of Plasmolytica on the Hypersensitive Reaction Induced by Bacteria in Tobacco: a Comparison With the Virus-Induced Hypersensitive Reaction. A. Gulyás, Research scientist, Institute of Plant Physiology, Hungarian Academy of Sciences, H-6701 Szeged, Hungary; B. Barna(2), Z. Klement(3), and G. L. Farkas(4). (2)(3)Research scientist and principal plant bacteriologist, respectively, Research Institute for Plant Protection, Budapest, Hungary; (4)Director, Institute of Plant Physiology, Hungarian Academy of Sciences, H-6701 Szeged, Hungary. Phytopathology 69:121-124. Accepted for publication 15 August 1978. Copyright 1979 The American Phytopathological Society. DOI: 10.1094/Phyto-69-121.

Since plasmolysis inhibits the hypersensitive reaction (HR) induced by viruses, a study was undertaken to investigate the effect of solutions of selected plasmolyzing agents (plasmolytica) on the HR induced by incompatible bacteria (Pseudomonas pisi, Pseudomonas phaseolicola, and Xanthomonas vesicatoria) in Xanthi tobacco leaves. Leakage of electrolytes from disks of tissue from leaves injected with bacterial suspensions was measured in the presence of different concentrations of nonpermeating (mannitol), slow-permeating (sucrose), and rapid-permeating (ethylene glycol) plasmolytica, respectively. Only the nonpermeating and slow-permeating plasmolytica inhibited the bacterial HR. Although the development of viral HR is sharply inhibited by osmotica above the iso-osmotic value, the inhibition of bacterial HR (as a function of the concentration of the plasmolytica) was gradual. The bacterial HR, therefore, does not seem to be affected by the turgor of the host cells. The onset of bacterial HR was inhibited by the plasmolytica irrespective of the time of treatment after inoculation.