Methyl salicylate production in tomato affects biotic interactions

Plant J. 2010 Apr 1;62(1):124-34. doi: 10.1111/j.1365-313X.2010.04132.x. Epub 2010 Jan 6.

Abstract

The role of methyl salicylate (MeSA) production was studied in indirect and direct defence responses of tomato (Solanum lycopersicum) to the spider mite Tetranychus urticae and the root-invading fungus Fusarium oxysporum f. sp. lycopersici, respectively. To this end, we silenced the tomato gene encoding salicylic acid methyl transferase (SAMT). Silencing of SAMT led to a major reduction in SAMT expression and MeSA emission upon herbivory by spider mites, without affecting the induced emission of other volatiles (terpenoids). The predatory mite Phytoseiulus persimilis, which preys on T. urticae, could not discriminate between infested and non-infested SAMT-silenced lines, as it could for wild-type tomato plants. Moreover, when given the choice between infested SAMT-silenced and infested wild-type plants, they preferred the latter. These findings are supportive of a major role for MeSA in this indirect defence response of tomato. SAMT-silenced tomato plants were less susceptible to a virulent strain of F. oxysporum f. sp. lycopersici, indicating that the direct defense responses in the roots are also affected in these plants. Our studies show that the conversion of SA to MeSA can affect both direct and indirect plant defence responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Fusarium / physiology*
  • Gene Expression Regulation, Plant
  • Gene Silencing
  • Host-Pathogen Interactions
  • Methyltransferases / genetics
  • Methyltransferases / metabolism*
  • Mite Infestations / genetics
  • Oils, Volatile / metabolism
  • Plant Diseases / genetics
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plant Roots / genetics
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / metabolism
  • Predatory Behavior
  • RNA, Plant / genetics
  • Salicylates / metabolism*
  • Solanum lycopersicum / genetics
  • Solanum lycopersicum / metabolism*
  • Terpenes / metabolism
  • Tetranychidae / physiology*

Substances

  • Oils, Volatile
  • Plant Proteins
  • RNA, Plant
  • Salicylates
  • Terpenes
  • Methyltransferases
  • salicylic acid carboxyl methyltransferase
  • methyl salicylate