RELATIONSHIPS BETWEEN ELECTROLYTE LEAKAGE FROM PYRUS-COMMUNIS AND VIRULENCE OF ERWINIA-AMYLOVORA

One of the first events associated with the interaction between a necrogenic bacterial pathogen and cells of plant tissues is the leakage of electrolytes and nutrients through the plant cell membranes. A technique, used previously to measure electrolyte leakage from bean leaves infiltrated with Pseudomonas syringae pv. syringae, was adapted and used to study the pattern and extent of leakage from pear tissues treated with wild-type strains and transposon mutants of Erwinia amylovora of different levels of virulence. Results showed that electrolyte leakage from pear treated with E. amylovora can be easily and reliably assessed. Furthermore, there is a correlation (with extracellular polysaccharide producing strains) between the level of virulence of the strains and the amount of leaked electrolytes. © 1991 Academic Press Limited.