title: Association between border cell responses and localized root infection by pathogenic Aphanomyces euteiches.
abstract: OBJECTIVE
  The oomycete Aphanomyces euteiches causes up to 80 % crop loss in pea (Pisum sativum). Aphanomyces euteiches invades the root system leading to a complete arrest of root growth and ultimately to plant death. To date, disease control measures are limited to crop rotation and no resistant pea lines are available. The present study aims to get a deeper understanding of the early oomycete-plant interaction at the tissue and cellular levels.
  
  
  METHODS
  Here, the process of root infection by A. euteiches on pea is investigated using flow cytometry and microscopic techniques. Dynamic changes in secondary metabolism are analysed with high-performance liquid chromatography with diode-array detection.
  
  
  RESULTS
  Root infection is initiated in the elongation zone but not in the root cap and border cells. Border-cell production is significantly enhanced in response to root inoculation with changes in their size and morphology. The stimulatory effect of A. euteiches on border-cell production is dependent on the number of oospores inoculated. Interestingly, border cells respond to pathogen challenge by increasing the synthesis of the phytoalexin pisatin.
  
  
  CONCLUSIONS
  Distinctive responses to A. euteiches inoculation occur at the root tissue level. The findings suggest that root border cells in pea are involved in local defence of the root tip against A. euteiches. Root border cells constitute a convenient quantitative model to measure the molecular and cellular basis of plant-microbe interactions.
authors.affiliation: Laboratoire de Glycobiologie et Matrice Extracellulaire Végétale, EA4358, IFRMP 23, Plate-forme de Recherche en Imagerie Cellulaire de Haute Normandie, Université de Rouen, 76821 Mont Saint Aignan, France.
authors.forename: Marc Antoine
authors.initials: MA
authors.lastname: Cannesan
authors.forename: Christophe
authors.initials: C
authors.lastname: Gangneux
authors.forename: Arnaud
authors.initials: A
authors.lastname: Lanoue
authors.forename: David
authors.initials: D
authors.lastname: Giron
authors.forename: Karine
authors.initials: K
authors.lastname: Laval
authors.forename: Martha
authors.initials: M
authors.lastname: Hawes
authors.forename: Azeddine
authors.initials: A
authors.lastname: Driouich
authors.forename: Maïté
authors.initials: M
authors.lastname: Vicré-Gibouin
mesh_terms: D044744:Aphanomyces / Q000502:physiology*; D005434:Flow Cytometry; D054884:Host-Pathogen Interactions; D018532:Pisum sativum / Q000276:immunology / Q000378:metabolism / Q000382:microbiology*; D010636:Phenols / Q000378:metabolism; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology*; D018518:Plant Root Cap / Q000276:immunology / Q000378:metabolism / Q000382:microbiology*
chemical_list: D010636:Phenols