Publications des scientifiques de l'IRD

Kpémoua K., Boher Bernard, Nicole Michel, Calatayud Paul-André, Geiger Jean-Paul. (1996). Cytochemistry of defense responses in cassava infected by Xanthomonas campestris pv. manihotis. Canadian Journal of Microbiology, 42, p. 1131-1143. ISSN 0008-4166.

Titre du document
Cytochemistry of defense responses in cassava infected by Xanthomonas campestris pv. manihotis
Année de publication
1996
Type de document
Article
Auteurs
Kpémoua K., Boher Bernard, Nicole Michel, Calatayud Paul-André, Geiger Jean-Paul
Source
Canadian Journal of Microbiology, 1996, 42, p. 1131-1143 ISSN 0008-4166
Stems of susceptible and resistant cassava plants have been cytologically investigated for their defense reactions to an aggressive strain of Xanthomonas campestris pv. manihotis. Histochemistry, in conjunction with gold cytochemistry, revealed that in susceptible and resistant plants, phloem and xylem parenchyma cells displayed a wide range of responses that limited the bacterial growth within the infected plants. Lignification and suberization associated with callose deposition were effective mechanisms that reinforced host barriers in the phloem. In the infected xylem, vessels were plugged by a material of pectic and (or) lignin-like origin. Flavonoids have been seen to be incorporated in secondary cell wall coatings. These reactions occurred at a higher intensity in the resistant plants. The number of phoem and xylem cells producing autofluorescent compounds was higher in infected resistant plants than in susceptible plants. Reactions have been observed in the resistant variety only, such as secretion of phenol-like molecules by tyloses and hyperplasic activity of phloem cells that compartmentalized bacterial lysis pockets, which are potent secondary inoculum sources.Key words: lignin, suberin, callose, phenol, tylose, flavonoid, pectin
Plan de classement
Mécanismes biochimiques de la résistance [076MALPLA07]
Descripteurs
MALADIE DES PLANTES ; BACTERIE ; RELATION HOTE PARASITE ; RESISTANCE DE L'HOTE ; BIOCHIMIE ; COMPOSE PHENOLIQUE ; MICROSCOPIE ELECTRONIQUE
Localisation
Fonds IRD [F B010008188]
Identifiant IRD
fdi:010008188
Contact