title: Substrates of Peltigera Lichens as a Potential Source of Cyanobionts.
abstract: Photobiont availability is one of the main factors determining the success of the lichenization process. Although multiple sources of photobionts have been proposed, there is no substantial evidence confirming that the substrates on which lichens grow are one of them. In this work, we obtained cyanobacterial 16S ribosomal RNA gene sequences from the substrates underlying 186 terricolous Peltigera cyanolichens from localities in Southern Chile and maritime Antarctica and compared them with the sequences of the cyanobionts of these lichens, in order to determine if cyanobacteria potentially available for lichenization were present in the substrates. A phylogenetic analysis of the sequences showed that Nostoc phylotypes dominated the cyanobacterial communities of the substrates in all sites. Among them, an overlap was observed between the phylotypes of the lichen cyanobionts and those of the cyanobacteria present in their substrates, suggesting that they could be a possible source of lichen photobionts. Also, in most cases, higher Nostoc diversity was observed in the lichens than in the substrates from each site. A better understanding of cyanobacterial diversity in lichen substrates and their relatives in the lichens would bring insights into mycobiont selection and the distribution patterns of lichens, providing a background for hypothesis testing and theory development for future studies of the lichenization process.
authors.affiliation: Laboratory of Microbial Ecology, Department of Ecological Sciences, Faculty of Sciences, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago, Chile.
authors.forename: Catalina
authors.initials: C
authors.lastname: Zúñiga
authors.affiliation: Laboratory of Microbial Ecology, Department of Ecological Sciences, Faculty of Sciences, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago, Chile.
authors.forename: Diego
authors.initials: D
authors.lastname: Leiva
authors.affiliation: Laboratory of Microbial Ecology, Department of Ecological Sciences, Faculty of Sciences, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago, Chile.
authors.forename: Margarita
authors.initials: M
authors.lastname: Carú
authors.affiliation: Laboratory of Microbial Ecology, Department of Ecological Sciences, Faculty of Sciences, Universidad de Chile, Las Palmeras 3425, Ñuñoa, Santiago, Chile. jorlando@u.uchile.cl.
authors.forename: Julieta
authors.initials: J
authors.lastname: Orlando
mesh_terms: D000458:Cyanobacteria / Q000235:genetics*; D008011:Lichens / Q000382:microbiology / Q000502:physiology*; D046937:Nostoc / Q000235:genetics; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017423:Sequence Analysis, RNA; D012988:Soil Microbiology; D013559:Symbiosis
chemical_list: D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S
keywords: Cyanobacteria; Nostoc; Peltigera; Photobiont availability; Terricolous lichens