Bacterial cyclic â(1-2) glucan acts in systemic supression of plant defense response.

LUCIANO RIGANO, CAROLINE PAYETTE, GENEVIÈVE BROUILLARD, MARIA ROSA MARANO, LAURA ABRAMOWICZ, PABLO TORRES, MAXIMINA YUN, ATILIO PEDRO CASTAGNARO, MOHAMED ELOIRDI, MATHIEU LANGLOIS, JOHN MAXWELL DOW, KAMAL BOUARAB AND ADRIAN VOJNOV.

Edmonton, Canada

Simposio; Plant Canada; 2005

Plant Canada

Plants are able to defend themselves against attack by a variety of potential pathogens through the deployment of both constitutive and induced defenses.  To cause disease, a successful pathogen must counter or evade pre-formed defenses and suppress or fail to elicit induced defences. We show here a systemic suppression of plant immune responses by the extracellular cyclic b-(1,2)-glucan of the phytopathogen Xanthomonas campestris pv. campestris that is associated with the transport of the molecule throughout the plant. This is, to our knowledge, the first report showing that a phytopathogen suppressor is systemically transported. Systemic suppression is a novel counter-defensive strategy that may facilitate pathogen spread in plants, and may have important implications for the understanding of plant-pathogen co-evolution and for the development of phytoprotection measures.