Differential activation of defense-related genes in susceptible and resistant pepper cultivars infected with Phytophthora capsici

J Plant Physiol. 2008 Jul 7;165(10):1120-4. doi: 10.1016/j.jplph.2007.11.008. Epub 2008 Feb 19.

Abstract

This study investigated the expression pattern of genes encoding for a basic PR-1 protein, a basic beta-1,3-glucanase, a peroxidase, and a sesquiterpene cyclase involved in defense responses in three pepper cultivars with different levels of resistance to Phytophthora capsici. All genes were up-regulated in infected stems of the pepper cultivars, with expression being detected 8h post-inoculation. mRNA levels of these genes increased markedly by 24h post-inoculation, and maximal induction levels were observed for the PR-1 and sesquiterpene cyclase genes. PR-1, peroxidase, and sesquiterpene genes were always expressed at higher levels in resistant cultivars than in the susceptible cultivar, although up-regulation was observed in both, suggesting that the differences between these pepper genotypes in susceptibility and resistance are a matter of the timing and magnitude of the defense response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Capsicum / metabolism*
  • Capsicum / microbiology*
  • Gene Expression Regulation, Plant / physiology*
  • Genetic Predisposition to Disease
  • Phytophthora / physiology*
  • Plant Diseases / genetics*
  • Plant Diseases / microbiology
  • Plant Proteins / genetics
  • Plant Proteins / metabolism

Substances

  • Plant Proteins