title: Reflexions on some aspects of the interactions among ROS, RNS, and Ca(2+) in response to a mycorrhizal or a pathogenic fungus.
abstract: In vivo redox activities in the apoplast of axenically cultured intact seedling roots (superoxide anion generation, and superoxide dismutase and peroxidase activities) in contact with the compatible arbuscular mycorrhizal fungus (AMF) were clearly attenuated in comparison with those in contact with the pathogenic fungus (PF) or treated with MeJA, even at the early stages of treatment. Contact of roots with the AMF did not enhance the biosynthesis of phenolic compounds (total phenolics, flavonoids, and phenylpropanoid glycosides), while contact with the PF significantly enhanced the biosynthesis of all phenolic fractions. Reactive oxygen and nitrogen species both seemed to be involved in these responses from the first moments of contact, but the fluorescence imaging of roots showed that ROS were mainly accumulated in the apoplast while NO was mainly stored in the cytosol. In conclusion, intact olive seedling roots clearly differentiated between AMF and PF.
authors.affiliation: a FBCMP Research Group; Extremadura University ; Badajoz , Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Espinosa
authors.affiliation: a FBCMP Research Group; Extremadura University ; Badajoz , Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Garrido
authors.affiliation: a FBCMP Research Group; Extremadura University ; Badajoz , Spain.
authors.forename: María Carmen
authors.initials: MC
authors.lastname: Álvarez-Tinaut
mesh_terms: D002118:Calcium / Q000378:metabolism*; D008954:Models, Biological; D038821:Mycorrhizae / Q000502:physiology*; D031658:Olea / Q000378:metabolism* / Q000382:microbiology*; D026361:Reactive Nitrogen Species / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; D002118:Calcium
keywords: defense reactions; mycorrhiza; nitric oxide; olive seedlings roots; pathogenic fungi; reactive oxygen species; redox activities; rhizophagus irregularis; verticillium dahliae