Ethylene-dependent salicylic acid regulates an expanded cell death response to a plant pathogen

Plant J. 2001 Feb;25(3):315-23. doi: 10.1046/j.1365-313x.2001.00968.x.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Death*
  • Ethylenes / metabolism*
  • Lycopersicon esculentum / cytology*
  • Lycopersicon esculentum / microbiology
  • Salicylic Acid / metabolism*
  • Signal Transduction
  • Xanthomonas campestris / physiology*


  • Ethylenes
  • ethylene
  • Salicylic Acid