title: Iron and reactive oxygen responses in Pinus sylvestris root cortical cells infected with different species of Heterobasidion annosum sensu lato.
abstract: Defence mechanisms in trees are not well understood. We assessed whether distribution of iron ions and their co-localisation with reactive oxygen species in Pinus sylvestris root cells reflect differential preferences of the pathogens Heterobasidion annosum sensu stricto, H. parviporum and H. abietinum to the host. Strains of H. annosum s.s. characterised by a greater preference for P. sylvestris induced accumulation of superoxide (O(2)(-)) in host cells 6 h after inoculation, whereas two peaks in accumulation of O(2)(-) (after 4 and 48 h) were observed after infection with strains of the pathogens H. parviporum and H. abietinum, which have a lower preference for P. sylvestris. Moreover, strains of H. annosum s.s. caused increased production of hydrogen peroxide (H(2)O(2)) in P. sylvestris cells, in contrast with strains of the other two species (H. parviporum and H. abietinum). Following inoculation with H. annosum s.s. strains, H(2)O(2) was correlated negatively with O(2)(-) and correlated positively with ferrous iron (Fe(2+)). Co-localisation of Fe(3+) with H(2)O(2) may suggest that they are involved in inducing hypersensitive responses and eventually cell death in roots inoculated with H. annosum s.s. strains, in contrast with H. parviporum, in which other mechanisms operate when the host is parasitised.
authors.affiliation: Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland. mucha_joanna@wp.pl
authors.forename: Joanna
authors.initials: J
authors.lastname: Mucha
authors.forename: Marzenna
authors.initials: M
authors.lastname: Guzicka
authors.forename: Piotr
authors.initials: P
authors.lastname: Lakomy
authors.forename: Marcin
authors.initials: M
authors.lastname: Zadworny
mesh_terms: D001487:Basidiomycota / Q000502:physiology*; D016923:Cell Death; D005290:Ferric Compounds / Q000378:metabolism; D005296:Ferrous Compounds / Q000378:metabolism; D058507:Host Specificity; D054884:Host-Pathogen Interactions / Q000502:physiology; D006861:Hydrogen Peroxide / Q000378:metabolism; D007501:Iron / Q000378:metabolism*; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D041605:Pinus sylvestris / Q000166:cytology / Q000378:metabolism* / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology*; D018517:Plant Roots / Q000166:cytology / Q000378:metabolism / Q000382:microbiology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D016897:Respiratory Burst; D036226:Seedlings / Q000166:cytology / Q000378:metabolism / Q000382:microbiology; D013045:Species Specificity; D013194:Staining and Labeling; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors; D014197:Trees
chemical_list: D005290:Ferric Compounds; D005296:Ferrous Compounds; D017382:Reactive Oxygen Species; D013481:Superoxides; D006861:Hydrogen Peroxide; D007501:Iron; D010100:Oxygen