VIEW ARTICLE

Physiology and Biochemistry

Inhibition by Antibacterial Compounds of the Hypersensitive Reaction Induced by Pseudomonas pisi in Tobacco. Myron Sasser, Associate professor, Department of Plant Science, University of Delaware, Newark 19711; Phytopathology 72:1513-1517. Accepted for publication 13 April 1982. Copyright 1982 The American Phytopathological Society. DOI: 10.1094/Phyto-72-1513.

Screening of 50 selected antibacterial compounds for inhibition of the hypersensitive reaction (HR) induced by Pseudomonas pisi in tobacco identified 19 experimentally useful compounds. None of the materials active against bacterial cell wall synthesis inhibited the HR, but some membrane-active compounds and some of those that inhibit bacterial RNA synthesis or protein synthesis were effective. Bacterial mutants resistant to specific compounds induced the HR in the presence of these compounds, indicating that their effects were on the bacteria rather than on the plants. Apparent selective inhibition of bacterial plasmid replication by acridine compounds reduced the ability of P. pisi to induce the HR in tobacco. Inhibition of the bacteria-induced HR by chloramphenicol was reversible while that caused by streptomycin above 64 μg/ml was essentially irreversible. The use of twofold serial dilutions of bacterial suspensions increased the sensitivity of the HR evaluation.