Suppression of plant defence in rhizobia-legume symbiosis

Trends Plant Sci. 2002 Oct;7(10):440-4. doi: 10.1016/s1360-1385(02)02336-1.

Abstract

The symbiosis between rhizobia and legumes is characterized by the formation of dinitrogen-fixing root nodules. Although rhizobia colonize roots in a way that is reminiscent of pathogenic microorganisms, no host plant defence reactions are triggered during successful symbioses. Nevertheless, the plants obviously control the invading bacteria; failure in effective nodule formation or infections with rhizobia defective in surface polysaccharides often result in pathogenic responses. This article focuses on whether and how defence responses in effective symbiosis might be suppressed. Recent results suggest a central role for rhizobial polysaccharides acting as antagonists in the negative regulation of defence induction.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Carbohydrate Sequence
  • Fabaceae / genetics
  • Fabaceae / growth & development*
  • Fabaceae / microbiology
  • Immunity, Innate / genetics
  • Molecular Sequence Data
  • Molecular Structure
  • Oligosaccharides / chemistry
  • Oligosaccharides / metabolism
  • Plant Diseases / genetics
  • Plant Diseases / microbiology
  • Plant Roots / genetics
  • Plant Roots / growth & development
  • Plant Roots / microbiology
  • Polysaccharides, Bacterial / chemistry
  • Polysaccharides, Bacterial / metabolism
  • Rhizobiaceae / genetics
  • Rhizobiaceae / growth & development*
  • Rhizobiaceae / metabolism
  • Symbiosis / genetics
  • Symbiosis / physiology*

Substances

  • Oligosaccharides
  • Polysaccharides, Bacterial