Abstract

The ectomycorrhizospheric habitat contains a diverse pool of organisms, including the host plant, mycorrhizal fungi, and other rhizosphere microorganisms. Different signaling molecules may influence the ectomycorrhizal symbiosis.

Here, we show that the mutual symbiosis between the basidiomycete Tricholoma vaccinum and Norway spruce (Picea abies) shapes the surrounding mycorrhizosphere. In a forest biotope, this was characterized by a high diversity in basidiomycetes and a rich bacterial community. This consisted of mainly bacteria plant growth promoting abilities dominated by Rhizobiales, with Nitrobacter winogradski being most abundant (3.9 %). Other taxa mainly were pseudomonads and bacilli. The bacterial isolates showed symbiosis-relevant traits with 74 % producing the phytohormone indole-3-acetic acid, 23 % producing siderophores, and 23 % mobilizing phosphate.

The mycorrhizal fungus T. vaccinum was able to excrete plant hormones into the medium upon axenic cultivation. These include auxins, salicylic and abscisic acid, and jasmonates. The spruce roots exudated auxins and salicylic acid. With these compounds present in soil of a natural ectomycorrhizospheric habitat, a communication network with a response of T. vaccinum to the environmentally available salicylic and abscisic acids, which led to altered hyphal branching relevant for mycorrhization. In addition, the fungus protected the mycorrhizal tree against the spruce pathogens Botrytis cinerea and Heterobasidion annosum. Thus, the finely tuned phytohormone interactions in the mycorrhizosphere represent a specifically rich system to study microbial communication.

Abstract

Demand for non-meat protein sources has grown extensively in Finland as well as in rest of Europe. In Finland wood processing industries produces vast amounts of residues, which could be suitable for production of edible mushrooms thus increasing the local protein production as well as harboring circular economy. Our aim in this study was to test cultivation of Polyporus squamosus on substrates from wood processing industries, and evaluate the feasibility of cultivation. Populus tremula and Betula pendula sawdust and chips were used as substrates. Two strains of P. squamosus originating from Finland were used in this study. The substrate bags of 1 kg dry weight were filled as follows: 1) 40% of wood sawdust and 60% of wood chips in the case of P. tremula species 2) B. pendula substrate bags were filled with 100% wood chips 3) Used coffee and rye bran were tested as nutritional additives, 20% of the total substrate bag weight for both nutrients and wood chips from the two species. A total of ten replicates per each substrate formula were inoculated with 150 ml of two strains of P. squamosus barley spawn. When the substrate bags were completely colonized, they were kept at 26^°C with a relative humidity of 80% to support fruiting body formation. The biological efficiency was calculated considering the kilograms of fresh fruit body per kilogram of dry substrate. First flush was first observed one month after inoculation, suggesting that crops can be obtained within 2 months. The substrate formula that was found to be the most suitable for fruit body formation was the one containing 20% of rye addition in both B. pendula and P. tremula wood residues. Differences between mycelium growth rates were observed between the fungal strains, emphasizing the importance for strain selection most suitable for commercial cultivation in future. Our results suggest that B. pendula and P. tremula wood residues serve as equally suitable substrates which can be utilized for the cultivation of P. squamosus.

Abstract

Comparative studies targeting the drivers of endophytic fungal biodiversity are rare and identified multiple effectors, such as plant chemistry, climate and seasonal attributes. Our project aimed to study the pattern of the leaf-associated mycobiomes of European beech (Fagus sylvatica) at different altitudes to reveal diversity, composition and seasonal dynamics of fungal endophytes by a combination of metabarcoding, cultivation and subsequent ecological analyses. An experimental field site consisting of 100 (2-years old beech) trees was established called ‘beech phytometer system’ at two altitudes (517 and 975 m a.s.l.) in a German mountain forest. Ten trees from each site were chosen and 10 leaves per tree were sampled. The following workflow included leaf biochemistry measurement and fungal DNA metabarcoding with 97% OTU threshold and biodiversity analysis for two continuous years: five trees from beech phytometer and five trees from surrounding beech trees. Metabarcoding resulted in a total of 15,703,599 demultiplexed and quality filtered ITS1 reads from 165 samples. Clustering at 97% similarity resulted in 1199 OTUs. In addition, 438 isolates from an autumn sampling event were cultivated via the dilution-to-extinction method; endophytes were identified via barcoding based on ribosomal ITS (internal transcribed spacer) markers and Sanger sequencing. A significant correlation of community composition with elevation was observed. The mycobiome was little affected by the physiological state of the leaves; only a partial shift of taxonomic composition was observed from vital towards senescent leaves. Mycobiome diversity and composition correlated significantly with the origin of the trees, pointing to local habitat condition as the main driver. Under natural conditions, the mycobiome was more diverse at the lower elevation. Additionally, leaf chlorophyll and flavonoid contents showed negative correlations with fungal richness in natural stands. Metabarcoding and cultivation approach resulted in non-overlapping community compositions and pronounced differences in taxonomic classification and trophic stages. However, both methods revealed similar correlations of the fungal communities with local environmental conditions. Our results indicate undeniable advantages of metabarcoding over cultivation in terms of representation of the major functional guilds, rare taxa and diversity signals of leaf-inhabiting fungi. We observed a strong seasonal turnover in phyllosphere fungi in both habitats over the two years of investigation, suggesting that the plant- fungal system not only responds to cyclic climatic conditions but depends as well on various parameters, e.g., geographic position, substrates age and surrounding vegetation. In general, the altitudinal difference is the most important explaining factor for community differences, which shapes many dependent abiotic and biotic habitat factors. Regarding cost and time per sequence, metabarcoding is superior to cultivation approaches and offers surprisingly profound insights by yielding much more data, allowing to test at once multiple hypotheses in fungal ecology.

Abstract

Species of fungi are not immune to the threats that put animal and plant species at risk, i.e., habitat loss, loss of symbiotic hosts, pollution, over exploitation, and climate change. Yet, fungal conservation is only now receiving significant attention. So, it is not surprising that fungi have rarely been included in broader conservation discussions, policy decisions, or land management plans. A critical way to help politicians and citizens be more aware of the importance of fungi and the need to conserve them is to have fungal species included in the IUCN (International Union for Conservation of Nature) Global Red List. The Red List is a compilation of rigorous assessments of the extinction risk of individual species made using strict universal criteria and categories (www.iucnredlist.org). Until recently, some thought that it was not possible to rigorously assess the conservation status of fungal species using IUCN criteria because of the unique biology of fungi and insufficient information on their taxonomy, distribution and ecology. However, much progress has been made to address these challenges.

The voluntary Global Fungal Red List Initiative aims to facilitate and coordinate efforts by the global mycological community to get species of threatened fungi assessed and included in the global IUCN Red List. The goal of the initiative is to raise awareness of fungal conservation among mycologists, the conservation community, policy makers and the general public. By the end of 2018, more than 100 fungi will be in. A broader engagement by the mycological community is needed to keep this initiative moving forward with the goal of having a sufficient number of species assessed to provide an indication of the conservation status of fungi in relation to other groups of organisms. The initiative needs additional contributors with knowledge of distributions, ecologies and population trends of individual species as well as help with checking facts and suggesting species to assess. Gaps in our knowledge of fungal diversity, distributions, phenology, and responses to threats will continue to pose significant challenges to fungal conservation initiatives for the foreseeable future. However, we have sufficient knowledge on an increasing number of species to enable fungi and mycologists to play a larger role in regional, national, and global fungal conservation activities. Contribute by contacting the Global Fungal Red List Initiative or directly through their web-page.

Abstract

The genus Cryptostylis is unique among Australian sexually deceptive orchids in that all five species are pollinated by the same wasp species - Lissopimpla excelsa. Cryptostylis erecta, C. leptochila, C. hunteriana and C. subulata occur sympatrically in eastern Australia, while C. ovata is restricted to Western Australia. Despite their sympatry and pollinator sharing, eastern Australian Cryptostylis do not hybridise. We investigated the mycorrhizal diversity associated with Australian Cryptostylis to determine whether an inter-species difference in mycorrhizal association could be contributing to the failed establishment of hybrids. We examined a minimum of 25 plants from across five populations of each species, except for the rare C. hunteriana where we analysed only two populations. Results of both fungal isolations and direct sequencing of the ITS locus from peloton rich orchid tissue show that all the Cryptostylis species are associated with closely related Tulasnella fungi. We discovered four previously unidentified Tulasnella operational taxonomic units (OTUs). Specifically, Tulasnella OTU A is shared by four Cryptostylis species, C. erecta, C. subulata, C. leptochila, and C. ovata. Tulasnella OTU B is only associated with C. ovata, while Tulasnella OTU C has associations both with C. erecta and C. subulata. Tulasnella OTU D is was only found in association with the vulnerable species, C. hunteriana. In addition to these four new OTUs, Cryptostylis were found to associate with T. prima and T. sphagneti, both of which are known to also associate with multiple species of sexually-deceptive Chiloglottis orchids. Tulasnella sphagneti was found to only associate with C. subulata, whereas T. prima also associates with C. leptochila and C. ovata. The association with C. ovata extends the known distribution of T. prima from eastern Australia to Western Australia. The Tulasnella symbionts of Cryptostylis all belong to a closely related group of species that are found with other sexually deceptive orchids in Australia such as Drakaea, Caleana and Arthrochilus. Due to the shared association with OTU A, mycorrhizal specificity is unlikely to explain the absence of hybrids in Australian Cryptostylis.

Abstract

Over the past decade, culture-independent approaches employing next-generation DNA sequencing have revolutionized our capacity to investigate the composition and dynamics of microbial communities (microbiomes). Major advances have been made on understanding human, animal, and plant microbiomes, however, less attention has been given to the microbial communities of fungi. Bacteria perform various functions in fungi and their reproductive structures (fruiting bodies), spanning from pathogenicity (e.g., mycoparasites) to growth promotion (e.g., mycorrhizal helper bacteria). However, how mushroom-associated bacteria assemble and function within fungi belonging to different ecological guilds and growing habits has yet to be addressed. To this end, we used Illumina high-throughput 16S rRNA amplicon sequencing to characterize bacterial communities in thirty-two fungal genera across Ascomycota and Basidiomycota. Through bioinformatic analyses of the ~6.4M raw sequences generated we recovered 1384 Operational Taxonomic Units (OTUs) across 160 samples. Proteobacteria (71.8%), Bacteroidetes (23.3%) Firmicutes (1.9%), and Actinobacteria (0.7%) were the most abundant phyla overall. Bacterial communities structured according to different fungal functional guilds (mycorrhizal, endophytic, saprophytic) as well as growing habitus (hypogeous, epigeous, wood-growing). The highest bacterial richness was recorded in Tuber, Chantarellus, Hydnum, and Morchella; the lowest in Ganoderma, Hericium, Paxillus, and Lyophyllum. The genus Bradyrhizobium was abundant in Tuber, but also present in Scleroderma, Elaphomyces, and Lycoperdon, all grouped by a similar sequestrate fruiting structure. Pseudomonas was highly abundant in Coprinus, Leatiporus, and Suillus, while Burkholderia were dominated inside Clavariadelphus, Grifola, and Hydnum. Bacteria belonging to Polaromonas, Pedobacter, and Janthinobacterium were all abundant in Helvella, Gyromitra, and Morchella which all share a similar fruiting morphology and belong to Pezizales. Our data demonstrate that fruiting bodies microbiomes relate to the functional guild of their fungal host, which raises the question of whether these bacteria provide symbiotic functions or depend upon specific ecological requirements. A wider sampling of fungi belonging to the same trophic guild, in different geographic areas, will improve the separation of community variations attributable to ecological habitat filtering from metabolic-based symbiotic interactions.

Abstract

Genus Lycoperdon was first established by Persoon in 1796 by describing L. perlatum as a type species. It is characterized by sub globose to pyriform basidomata with conspicuous sterile base and dehiscence by an apical pore. It is represented by 54 species worldwide. Recent molecular phylogenetic studies have widened the concept of the genus and new limits of Lycoperdon have been established by proposing many subgenera within the genus, i.e. Apioperdon, Bovistella, Lycoperdon, Morganella, Utraria and Vascellum. In Pakistan, twenty one (21) Lycoperdon spp. have been reported so far. During this investigation, eight (8) Lycoperdon species have been identified and described using morphological and molecular methods based on ITS-nrDNA region. Among these, three (3) belong to subgenus Vascellum, two (2) each to subgenera Bovistella and Lycoperdon and one (1) to subgenus Apioperdon. Out of these, three (3) species have been found previously undescribed viz., L. lahorense, L. olivoflavum, L. parvisporum, and reported here as new species. L. utriforme is a new record for Pakistan and three (3) species have been reported from new localities of the country. One taxon, previously published as Bovistella japonica on morphological basis has been shifted to subgenus Bovistella of genus Lycoperdon based on molecular analysis in this study.

Abstract

North American bats have experienced catastrophic population declines from white-nose syndrome (WNS), an emergent disease caused by the fungus Pseudogymnoascus destructans (Pd). Although Pd has a broad host range on hibernating bats in eastern North America, population-level impacts of WNS vary by host species. For example, little brown (Myotis lucifugus), northern long-eared (M. septentrionalis), and tricolored (Perimyotis subflavus) bats have experienced precipitous declines due to WNS, whereas species such as big brown (Eptesicus fuscus), gray (M. grisescens), and Virginia big-eared (Corynorhinus townsendii virginianus) bats appear to exhibit some degree of resistance to the disease and have not suffered such devastating losses. Mechanisms of WNS-resistance have not been fully elucidated, but are likely multifactorial. Microbial skin communities can influence host resistance to infectious diseases by inhibiting or competing with pathogens. We compared fungal assemblages on hibernating bat species with low or no WNS-related mortality (n=262) to WNS-susceptible bat species (n=163) using culture-dependent methods. The diversity and abundance of skin fungi differed between many of the bat species. Known WNS-resistant bat species had a mean of 2.5 ± 1.8 fungal genera per bat (mean Shannon index 0.48 ± 0.55), which was significantly higher than WNS-susceptible bats (1.1 ± 1.0 with a Shannon index of 0.12 ± 0.30; χ²=103.54, p < 2.2e-16). Of particular note was an abundance of certain yeast species (namely Debaryomyces spp.) on the skin of resistant bat species; these yeasts were absent or rare on the skin of bat species susceptible to WNS. Analyses to investigate potential relationships between fungal assemblages and resistance to WNS are underway.

Abstract

Benzene, toluene, ethylbenzene, and the isomers of xylene (BTEX) are volatile anthropogenic pollutants derived from petroleum products that cause harmful effects in humans and other organisms. Fungi were isolated from a 35-ha hypersaline coastal lagoon, Punta Cuchara Natural Reserve, Ponce, Puerto Rico, which is an important nursery for marine species and serves as an avian refuge. Coastal lagoons frequently are contaminated with BTEX. A total of 25 culture-dependent fungal species from the lagoon included the following: Aspergillus sp., Penicillium sp., Cladosporium sp., Trichoderma sp. Fusarium sp., Curvularia sp., Chaetomium sp., Blastoschizomyces capitatus, Candida albicans, C. glabrata, C. rugosa, C. parapsilosis, C. tropicalis, C. zeylanoides, Cryptococcus neoformans, C. albidus, and C. uniguttulatus, Geotrichum sp., Kluyveromyces sp., Prototheca zopfii, Rhodotorula minuta, R. mucilaginosa, Saccharomyces cerevisiae, Trichosporon cutaneum, and Yarrowia lipolytica. A static culture system, each consisting of a serum bottle capped with Teflon Mininert™ valves was used in each of three successive trials to determine degradation of BTEX by each fungi species. An aqueous mineral medium stock solution was prepared with NaNO3 (3.0 g/L), KCl (0.5 g/L), MgSO4 (0.5 g/L), FeSO4 (0.01 g/L), and K2HPO4 (1.0 g/L). Each fungal species was inoculated at a concentration of 1 x 104 yeast cells/mL into the static culture system with a mixture of 118.75 mL of the mineral stock solution and 6.25 mL of BTEX. The BTEX was the only source of energy and carbon. The inoculation was incubated for 150 hr at 25oC. HPLC-DAD method was used to determine the biodegradation of the BTEX in each system by each fungus. The majority of the fungi species degraded the BTEX completely, although traces of BTEX were detected for some species. Thus, funguses species appear to serve as biodegradation organisms in hypersaline lagoons, many of which could be contaminated from petroleum spills.

Abstract

Ammonia fungi are a fungal group that forms a fungal community sequentially at the restricted sites of animal materials (e.g., decomposing carcasses and animal waste) or artificial disturbance of nitrogen compounds. Researches about ammonia fungi are fragmentary at global scale, especially sparse in tropical areas as Southeast Asia. In Vietnam, ammonia fungal study was firstly conducted by urea application in Pinus kesiya forest, DaLat, Lam Dong Province from 2010 with a new record of Hebeloma vinosophyllum at Southeast Asia. In 2012, 2 urea treated plots in forest of Pinus dalatensis and Quercus spp. at BiDoup - Nui Ba National Park, Lam Dong Province were observed in 7 months. Amblyosporium botrytis, Ascobolus denudatus, Lyophyllum tylicolor, and Coprinopsis sp. appeared in early phase, followed by Hebeloma lactariolens, Hebeloma sp., Laccaria sp. in late phase of ammonia fungi. For investigating the composition of ammonia microfungi, litter from Pinus and Quercus forests at BiDoup - Nui Ba National Park was applied urea in ex-situ model. The aqueous urea solution was added to litter for setting up the concentration of 40mgN/g dry litter, 20mgN/g dry litter. Based on morphological characteristics and ITS analyses, 14 isolates were identified to genus as Talaromyces, Fusarium and Pseudallescheria. These preliminary results contributed to ammonia fungi data in Vietnam, especially ammonia microfungi data. In further experiments, physiological characteristics of isolated microfungi will be studied.

Abstract

Mushrooms are the fleshy spore-bearing fruiting bodies of fungi. Wild mushrooms are source of many different nutraceuticals such as unsatured fatty acids, phenolic compounds, tocopherols, ascorbic acid, carotenoids and alkaloids and nutrients such as proteins, fats, ash, fiber, moisture and carbohydrates. Nepal possesses diverse phytogeographical zones related to altitude and other factors, and rich in wild mushrooms. The information and knowledge about nutritional and nutraceutical values of wild mushrooms is limited and poor. Therefore, the present study is undertaken to document the use of wild edible mushrooms and analyze their nutritive values. Herein, it was reported and compared the nutritional value and neutraceutical values of the wild mushroom species; Laetiporus sulphureus, Polypore sp., Trametes elegans , Trichaptum biforme, Lenzites betulina, Stereum complicatum, Trametes versicolor, Trichaptum subchartaceum, and Ganoderma Lucidium. The nutritional and nutraceutical properties analyzed according Association of Official Analytical Chemists (AOAC) and spectrophotometrically respectively. These mushrooms (samples) were rich in proteins (6.8- 60.23%) and fibers were range from 0.174 - 36.38% and contained fat range from 3.642- 14.6%. The carbohydrate contents ranged from 7.058 to 59% (on the basis of dry weight). Similarly; ash content and moisture content ranges from 10- 19% and10-16% respectively. The protein content was highest in Ganoderma Lucidium. (G. lucidium) and lowest in Trametes elegans (T. elegans). The fat content was highest in L. sulphureu and lowest in G. lucidium. . The analysis revealed that the total phenolic contents ranged from 3.95 to 10.05 mg ml^-1. Similarly, the total flavonoid contents ranged from 2.149 to 11.36 mg ml^-1. The result indicated the high levels of antioxidants activity thus making mushrooms suitable to be used as functional foods or nutraceutical sources. Therefore, this study provides new information regarding chemical properties of wild mushrooms, which is very important for the biodiversity characterization.

Abstract

Fungi and plants often form intimate relationships that have influenced the ecology and evolution of both groups in a significant way. The phyllosphere (i.e. the aboveground parts of plants) is one of the interfaces of plant-fungus interaction that has gained recent attention, as it has been hypothesized that the fungi inhabiting it can have beneficial effects on their host. Additionally, high-throughput amplicon based diversity assessments have shown that this habitat harbors an enormous species diversity of non-symptomatic fungi. In this study, we applied NGS amplicon sequencing to understand the influence of geography and host genotype on the structure of fungal communities in replicates of three different clonal Eucalyptus lineages in two geographic locations of South Africa. Additionally, we studied the formation of fungal communities in seedlings from these Eucalyptus clones, grown in an incubator and subsequently in a nursery. Our analyses on the plantation trees show that the structure of fungal communities is influenced by the different geographic locations. The fungal communities of seedlings were unique to their environment and showed a high turnover when moved between locations.