title: Ethylene-dependent salicylic acid regulates an expanded cell death response to a plant pathogen.
abstract: The molecular events associated with susceptible plant responses to disease-causing organisms are not well understood. We have previously shown that ethylene-insensitive tomato plants infected with Xanthomonas campestris pv. vesicatoria have greatly reduced disease symptoms relative to wild-type cultivars. Here we show that salicylic acid (SA) is also an important component of the susceptible disease response. SA accumulates in infected wild-type tissues and is correlated with necrosis but does not accumulate in ethylene-insensitive plants. Exogenous feeding of SA to ethylene-deficient plants restores necrosis, indicating that reduced disease symptoms are associated with failure to accumulate SA. These results indicate a mechanism for co-ordination of phytohormone signals that together constitute a susceptible response to pathogens.
authors.affiliation: Department of Horticultural Sciences, University of Florida, Gainesville, FL 32611, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: O'Donnell
authors.forename: J B
authors.initials: JB
authors.lastname: Jones
authors.forename: F R
authors.initials: FR
authors.lastname: Antoine
authors.forename: J
authors.initials: J
authors.lastname: Ciardi
authors.forename: H J
authors.initials: HJ
authors.lastname: Klee
mesh_terms: D016923:Cell Death; D005030:Ethylenes / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000166:cytology* / Q000382:microbiology; D020156:Salicylic Acid / Q000378:metabolism*; D015398:Signal Transduction; D016959:Xanthomonas campestris / Q000502:physiology*
chemical_list: D005030:Ethylenes; C036216:ethylene; D020156:Salicylic Acid