Suppression of plant defence in rhizobia–legume symbiosis

• Published in: Trends in plant science 2002-10, Vol.7 (10), p.440-444
• Main Author: Mithöfer, Axel
• Format: Article
• Language: English
• Subjects: Agonist; Agronomy. Soil science and plant productions; antagonist; Biological and medical sciences; Carbohydrate Sequence; Economic plant physiology; Fabaceae - genetics; Fabaceae - growth & development; Fabaceae - microbiology; Fundamental and applied biological sciences. Psychology; Immunity, Innate - genetics; legumes; Molecular Sequence Data; Molecular Structure; Oligosaccharides - chemistry; Oligosaccharides - metabolism; Parasitism and symbiosis; plant defence suppression; Plant Diseases - genetics; Plant Diseases - microbiology; Plant physiology and development; Plant Roots - genetics; Plant Roots - growth & development; Plant Roots - microbiology; Polysaccharides, Bacterial - chemistry; Polysaccharides, Bacterial - metabolism; receptor; Rhizobiaceae - genetics; Rhizobiaceae - growth & development; Rhizobiaceae - metabolism; Rhizobium; Symbiosis; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...); Symbiosis - genetics; Symbiosis - physiology
• ISSN: 1360-1385; 1878-4372
• DOI: 10.1016/S1360-1385(02)02336-1

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. Plant defence suppression in legume-rhizobia interactions is necessary to establish an effective dinitrogen-fixing symbiosis. Recent results suggest a central role for rhizobial polysaccharides acting as antagonists in a negative regulation of defence induction.