Nowadays endosymbiotic associations usually are excluded from lichen-definitions (Hawksworth and Honegger 1994). The species name ' Geosiphon pyrifome' was sometimes used for the fungus as well as for the symbiosis, because the latter often was regarded as 'phycomycetous lichen'. Presently, field sites around the small village Bieber in the Spessart Mountains (Germany) are the only known stable natural habitats world-wide (Mollenhauer 1992, Schüßler and Wolf 2005, Krüger and Krüger 2017). Probably, the symbiosis is geographically widespread in Central Europe but, due to its small size, rarely reported. There have been only six reports of this symbiosis being found in nature, at locations ranging from eastern Germany to Austria (Fig. 1), harboring endosymbiotic, filamentous cyanobacteria of the genus Nostoc. The coenocytic fungus forms unicellular, multinucleated cells ('bladders') of up to 2 mm in size (Fig. Wettstein (von Wettstein 1915) forms the only known fungal endocyanosis (endocytobiotic association with a cyanobacterium). The Geosiphon pyriformis - Nostoc symbiosis Also, a genome sequencing project that is driven by a Canadian laboratory is in progress (Krüger and Krüger 2017), but results were not published yet. Note that some data from some recent publications are not yet discussed here. The majority of plants, strictly speaking, do not have roots they have mycorrhizas.' Here, just a mention of the impact of the AM for the entire terrestrial ecosystem as stated by the BEG-Committee (25th May 1993) and many researchers in the field: 'The study of plants without their mycorrhizas is the study of artefacts. Implications of using this symbiosis for AM research are indicated elsewhere. Wettstein is the only known fungus forming endosymbiosis with cyanobacteria ( Nostoc punctiforme). However, the Geosiphon symbiosis also is highly interesting in itself, because Geosiphon pyriformis (Kütz.) v. We used and proposed the Geosiphon symbiosis as a model for the arbuscular mycorrhiza (AM) symbiosis. I am convinced that in future research on this organism will be revived - but it will have to start from scratch, including isolating the organisms from the natural habitat. I mention this so clearly, because this research could have pushed AM research significantly. Reviewers of grant proposals were too much sticking to mainstream approaches (and partly were just incompetent). Unfortunately, research in our lab had to be stopped, despite the enormous scientific potential of this symbiosis, also to unravel fundamental aspects of the arbuscular mycorrhizal (AM) symbiosis. Our group worked on the Geosiphon-Nostoc symbiosis for many years, starting from a relatively basic knowledge. A unique symbiosis between a glomeromycotan fungus and cyanobacteria.

Lineage 1 bot programmiren