title: Root exudate of Solanum tuberosum is enriched in galactose-containing molecules and impacts the growth of Pectobacterium atrosepticum.
abstract: Background and aims Potato (Solanum tuberosum) is an important food crop and is grown worldwide. It is, however, significantly sensitive to a number of soil-borne pathogens that affect roots and tubers, causing considerable economic losses. So far, most research on potato has been dedicated to tubers and hence little attention has been paid to root structure and function. Methods In the present study we characterized root border cells using histochemical staining, immunofluorescence labelling of cell wall polysaccharides epitopes and observation using laser confocal microscopy. The monosaccharide composition of the secreted exudates was determined by gas chromatography of trimethylsilyl methylglycoside derivatives. The effects of root exudates and secreted arabinogalactan proteins on bacterial growth were investigated using in vitro bioassays. Key Results Root exudate from S. tuberosum was highly enriched in galactose-containing molecules including arabinogalactan proteins as major components. Treatment of the root with an elicitor derived from Pectobacterium atrosepticum, a soil-borne pathogen of potato, altered the composition of the exudates and arabinogalactan proteins. We found that the growth of the bacterium in vitro was differentially affected by exudates from elicited and non-elicited roots (i.e. inhibition versus stimulation). Conclusions Taken together, these findings indicate that galactose-containing polymers of potato root exudates play a central role in root-microbe interactions.
authors.affiliation: Laboratoire Glycobiologie et Matrice Extracellulaire Végétale (EA 4358), Grand Réseau de Recherche VASI 'Végétal-Agronomie-Sol et Innovations' et Plate-Forme d'Imagerie Cellulaire (PRIMACEN) de Haute-Normandie, Normandie Université, Université de Rouen, 76821 Mont Saint Aignan Cedex, France.
authors.forename: Abdoul Salam
authors.initials: AS
authors.lastname: Koroney
authors.affiliation: Laboratoire Glycobiologie et Matrice Extracellulaire Végétale (EA 4358), Grand Réseau de Recherche VASI 'Végétal-Agronomie-Sol et Innovations' et Plate-Forme d'Imagerie Cellulaire (PRIMACEN) de Haute-Normandie, Normandie Université, Université de Rouen, 76821 Mont Saint Aignan Cedex, France.
authors.forename: Carole
authors.initials: C
authors.lastname: Plasson
authors.affiliation: Laboratoire de Microbiologie Signaux Microenvironnement EA 4312, Normandie Université, Université de Rouen, 76821 Mont Saint Aignan Cedex, France.
authors.forename: Barbara
authors.initials: B
authors.lastname: Pawlak
authors.affiliation: Faculté des Sciences, Université A.M. de Niamey, B.P. 12022 Niamey, Niger.
authors.forename: Ramatou
authors.initials: R
authors.lastname: Sidikou
authors.affiliation: Laboratoire Glycobiologie et Matrice Extracellulaire Végétale (EA 4358), Grand Réseau de Recherche VASI 'Végétal-Agronomie-Sol et Innovations' et Plate-Forme d'Imagerie Cellulaire (PRIMACEN) de Haute-Normandie, Normandie Université, Université de Rouen, 76821 Mont Saint Aignan Cedex, France.
authors.forename: Azeddine
authors.initials: A
authors.lastname: Driouich
authors.affiliation: Laboratoire Glycobiologie et Matrice Extracellulaire Végétale (EA 4358), Grand Réseau de Recherche VASI 'Végétal-Agronomie-Sol et Innovations' et Plate-Forme d'Imagerie Cellulaire (PRIMACEN) de Haute-Normandie, Normandie Université, Université de Rouen, 76821 Mont Saint Aignan Cedex, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Menu-Bouaouiche
authors.affiliation: Laboratoire Glycobiologie et Matrice Extracellulaire Végétale (EA 4358), Grand Réseau de Recherche VASI 'Végétal-Agronomie-Sol et Innovations' et Plate-Forme d'Imagerie Cellulaire (PRIMACEN) de Haute-Normandie, Normandie Université, Université de Rouen, 76821 Mont Saint Aignan Cedex, France.
authors.forename: Maïté
authors.initials: M
authors.lastname: Vicré-Gibouin
keywords: Arabinogalactan proteins; Pectobacterium atrosepticum; Solanum tuberosum; border cells; exudates; galactose-containing polymers; mucilage; root; root exudates