Volatilomes of Cyclocybe aegerita during different stages of monokaryotic and dikaryotic fruiting

Abstract

Volatile organic compounds (VOC) are characteristic for different fungal species. However, little is known about VOC changes during development and their biological role. Therefore, we established a laboratory cultivation system in modified crystallizing dishes for analyzing VOC during fruiting body development of the dikaryotic strain Cyclocybe aegerita AAE-3 as well as four monokaryotic offspring siblings exhibiting different fruiting phenotypes. From these, VOC were extracted directly from the headspace (HS) and analyzed by means of gas chromatography-mass spectrometry (GC-MS). For all tested strains, alcohols and ketones, including oct-1-en-3-ol, 2-methylbutan-1-ol and cyclopentanone, were the dominant substances in the HS of early developmental stages. In the dikaryon, the composition of the VOC altered with ongoing fruiting body development and, even more drastically, during sporulation. At the latter stage, sesquiterpenes, especially Δ6-protoilludene, α-cubebene and δ-cadinene, were the dominant substances. After sporulation, the amount of sesquiterpenes decreased, while additional VOC, mainly octan-3-one, appeared. In the HS of the monokaryons, less VOC were present of which all were detectable in the HS of the dikaryon C. aegerita AAE-3. The results of the present study show that the volatilome of C. aegerita changes considerably depending on the developmental stage of the fruiting body.

Multilocus phylogeny- and fruiting feature-assisted delimitation of European Cyclocybe aegerita from a new Asian species complex and related species

“…Implications of the biogeographic diversity for C. aegerita as a model organism C. aegerita is used as model system to study or exploit diverse capabilities of mushroom-forming basidiomycetous fungi including fruiting (Herzog et al 2016), the production of biotechnologically relevant enzymes (Hofrichter et al 2020) or the biosynthesis of various metabolites including volatiles (Zhao et al 2003;Ngai et al 2005;Kögl et al 2007;Kleofas et al 2014;Hennicke et al 2019;Surup et al 2019;Tayyrov et al 2019;Orban et al 2020). Therefore, the here reported split-up of "C. aegerita s.l."…”

“…Also, this may reveal new variants of ribotoxins, terpenoids, peroxygenases, peroxidases or other carbohydrate active enzymes differing from those of C. aegerita AAE-3 (Gupta et al 2018;Surup et al 2019;Tayyrov et al 2019). Such data will be of general interest to a broad scientific community dealing with natural products chemistry including volatiles (Kleofas et al 2014;Citores et al 2019;Surup et al 2019;Tayyrov et al 2019;Orban et al 2020), enzyme biochemistry and biotechnology (Hofrichter et al 2015;Wang et al 2017;Karrer and Rühl 2019;Hofrichter et al 2020), or developmental biology (Herzog et al 2016).…”

The Pacific Tree-Parasitic Fungus Cyclocybe parasitica Exhibits Monokaryotic Fruiting, Showing Phenotypes Known from Bracket Fungi and from Cyclocybe aegerita

“…Moreover, since a certain strain will not always achieve fruiting in every fruiting flush on every single plate, it seems likely that, e.g., the stromatic proliferations by C. parasitica ICMP 11668-4, might form even earlier in future fruiting trials. Ultimately, Orban et al [ 28 ] showed that some C. aegerita ‘mycelium-type’ monokaryons may prove themselves as (partially) fruiting-competent in setups other than the one by Herzog et al [ 18 ]. Accordingly, this might also apply to C. parasitica ICMP 11668-derived monokaryons that did not form any monokaryotic fruiting structures here (see Figure S2d–l ).…”

“…In comparison to the elongated initials formed by some C. aegerita AAE-3-derived monokaryons [ 18 , 28 ], elongated structures that are formed by C. parasitica ICMP 11668-9 seem to constitute something different. Although these structures look very similar to each other on the macroscopic level, both displaying a brown base and a white tip, microscopy reveals some noteworthy anatomical differences.…”

“…Within the genus Cyclocybe Velen., monokaryotic fruiting s.str. has so far only been recorded for C. aegerita [ 17 , 18 , 21 , 28 ]. Its occurrence in C. parasitica , the parasitic Pacific cousin of the former species [ 7 ], shows that this feature is not restricted to a single species of the genus.…”