Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 14, 1997
Publication Date: N/A
Technical Abstract: Identification of the components involved in the signaling between plants and potential pathogens is of fundamental importance to our understanding of disease development and induced resistance. Several isolates of Fusarium oxysporum produce a 24 kD protein in liquid culture that elicits physiological responses in detached leaves of both host and non- host species. The elicitor may have a significant role in fungal pathogenicity and/or induced plant resistance. Therefore, we are investigating elicitor signal transduction in a model plant system. Tobacco leaves, protoplasts, and cell cultures were treated with the F. oxysporum elicitor and various physiological responses were monitored. Detached leaves responded with concentration dependent necrosis after infiltration with the elicitor or uptake of the elicitor by the vascular tissue. Leaves also responded to the elicitor with the production of ethylene, and the peak in the rate of ethylene production occurred at about 3 h after treatment. Elicitor-induced ethylene production was enhanced by pretreating the leaves in 100 ppm of ethylene prior to elicitation. Tobacco protoplasts responded to nM concentrations of the elicitor with a rapid loss in viability. Elicited changes in transcript levels of defense related genes in tobacco leaves are also being measured, as well as ion flux in cell cultures. This research will hopefully enhance our understanding of plant/pathogen signaling and serve as the basis for future studies with the elicitor gene.