title: Spatial organization of the three-component lichen Peltigera aphthosa in functional terms.
abstract: The cephalolichen Peltigera aphthosa (L.) Willd. is characterized by lateral heterogeneity, which manifests itself in the presence of three thallus zones, referred to as the apical, basal and medial zone. These zones differ in terms of interaction between lichen bionts and their physiological activity. The apical thallus zone is more efficient in establishing a contact with cyanobacteria, because of a higher lectin content and a larger overall thallus surface area due to the presence of numerous mycobiont hyphae. Cephalodia are formed in this zone. The interaction between the mycobiont and cyanobiont is more intense in the medial zone. However, the establishment of the contact with cyanobacteria in this zone less probable. The spatial distribution of lectins in the thallus was determined. To reveal the differences in photosynthetic activity in three thallus zones, transient analysis of chlorophyll a fluorescence and the assessment of non-photochemical quenching of excited chlorophyll states were performed. Assimilation of absorbed light energy was more effective in the medial zone. The basal zone was characterized by decreased photosynthetic activity, lichen dissociation and thallus death.
authors.affiliation: Department of Bioengineering, Faculty of Biology, Moscow State University, Moscow, Russia.|National Research Nuclear University MEPhi, Centre for Humanities Research and Technology, Moscow, Russia.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Chekanov
authors.affiliation: Department of Bioengineering, Faculty of Biology, Moscow State University, Moscow, Russia.
authors.forename: Alexandr
authors.initials: A
authors.lastname: Feoktistov
authors.affiliation: Department of Bioengineering, Faculty of Biology, Moscow State University, Moscow, Russia.
authors.forename: Elena
authors.initials: E
authors.lastname: Lobakova
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D000458:Cyanobacteria / Q000502:physiology; D008011:Lichens / Q000166:cytology / Q000378:metabolism / Q000382:microbiology*; D010788:Photosynthesis / Q000502:physiology; D013559:Symbiosis / Q000502:physiology
chemical_list: D002734:Chlorophyll; D000077194:Chlorophyll A