Diversity and Specificity in Cyanobacterial Symbioses
نویسنده
چکیده
Cyanobacteria constitute one of the largest subgroups of Gram-negative photosynthetic prokaryotes and are of great evolutionary antiquity, dating back to the Precambrian (2.8–3.5 billion years ago). They are found worldwide in highly diverse ecosystems, from aquatic (limnic and marine) habitats to terrestrial systems and from polar to tropical regions of the globe. In terrestrial systems, nitrogen-fixing Nostoc is by far the most common genus and includes cyanobacteria capable of forming symbioses with a broad range of plants and other organisms. Hosts include fungi (Geosiphon species and lichenised fungi), bryophytes (liverworts and hornworts), aquatic ferns (genus Azolla), gymnosperms (cycads) and angiosperms (genus Gunnera) (Bergman et al. 1996).
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