RNA-seq transcriptome and pathway analysis of the medicinal mushroom Lignosus tigris (Polyporaceae) offer insights into its bioactive compounds with anticancer and antioxidant potential.

ETHNOPHARMACOLOGICAL RELEVANCE: Medicinal mushrooms belonging to the Lignosus spp., colloquially known as Tiger Milk mushrooms (TMMs), are used as traditional medicine by communities across various regions of China and Southeast Asia to enhance immunity and to treat various diseases. At present, three Lignosus species have been identified in Malaysia: L. rhinocerus, L. tigris, and L. cameronensis. Similarities in their macroscopic morphologies and the nearly indistinguishable appearance of their sclerotia often lead to interchangeability between them. Hence, substantiation of their traditional applications via identification of their individual bioactive properties is imperative in ensuring that they are safe for consumption. L. tigris was first identified in 2013. Thus far, studies on L. tigris cultivar sclerotia (Ligno TG-K) have shown that it possesses significant antioxidant activities and has greater antiproliferative action against selected cancer cells in vitro compared to its sister species, L. rhinocerus TM02®. Our previous genomics study also revealed significant genetic dissimilarities between them. Further omics investigations on Ligno TG-K hold immense potential in facilitating the identification of its bioactive compounds and their associated bioactivities. AIM OF STUDY: The overall aim of this study was to investigate the gene expression profile of Ligno TG-K via de novo RNA-seq and pathway analysis. We also aimed to identify highly expressed genes encoding compounds that contribute to its cytotoxic and antioxidant properties, as well as perform a comparative transcriptomics analysis between Ligno TG-K and its sister species, L. rhinocerus TM02®. MATERIALS AND METHODS: Total RNA from fresh 3-month-old cultivated L. tigris sclerotia (Ligno TG-K) was extracted and analyzed via de novo RNA sequencing. Expressed genes were analyzed using InterPro and NCBI-Nr databases for domain identification and homology search. Functional categorization based on gene functions and pathways was performed using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Clusters of Orthologous Genes (COG) databases. Selected genes were subsequently subjected to phylogenetic analysis. RESULTS: Our transcriptomics analysis of Ligno TG-K revealed that 68.06% of its genes are expressed in the sclerotium; 80.38% of these were coding transcripts. Our analysis identified highly expressed transcripts encoding proteins with prospective medicinal properties. These included serine proteases (FPKM = 7356.68), deoxyribonucleases (FPKM = 3777.98), lectins (FPKM = 3690.87), and fungal immunomodulatory proteins (FPKM = 2337.84), all of which have known associations with anticancer activities. Transcripts linked to proteins with antioxidant activities, such as superoxide dismutase (FPKM = 1161.69) and catalase (FPKM = 1905.83), were also highly expressed. Results of our sequence alignments revealed that these genes and their orthologs can be found in other mushrooms. They exhibit significant sequence similarities, suggesting possible parallels in their anticancer and antioxidant bioactivities. CONCLUSION: This study is the first to provide a reference transcriptome profile of genes expressed in the sclerotia of L. tigris. The current study also presents distinct COG profiles of highly expressed genes in Ligno TG-K and L. rhinocerus TM02®, highlighting that any distinctions uncovered may be attributed to their interspecies variations and inherent characteristics that are unique to each species. Our findings suggest that Ligno TG-K contains bioactive compounds with prospective medicinal properties that warrant further investigations. CLASSIFICATION: Systems biology and omics.

Advances in Mechanism and Application of Molecular Breeding of Medicinal Mushrooms: A Review.

With the development of molecular biology and genomics technology, mushroom breeding methods have changed from single traditional breeding to molecular breeding. Compared with traditional breeding methods, molecular breeding has the advantages of short time and high efficiency. It breaks through the restrictive factors of conventional breeding and improves the accuracy of breeding. Molecular breeding technology is gradually applied to mushroom breeding. This paper summarizes the concept of molecular breeding and the application progress of various molecular breeding technologies in mushroom breeding, in order to provide reference for future research on mushroom breeding.

Integrated omic profiling of the medicinal mushroom Inonotus obliquus under submerged conditions.

BACKGROUND: The Inonotus obliquus mushroom, a wondrous fungus boasting edible and medicinal qualities, has been widely used as a folk medicine and shown to have many potential pharmacological secondary metabolites. The purpose of this study was to supply a global landscape of genome-based integrated omic analysis of the fungus under lab-growth conditions. RESULTS: This study presented a genome with high accuracy and completeness using the Pacbio Sequel II third-generation sequencing method. The de novo assembled fungal genome was 36.13 Mb, and contained 8352 predicted protein-coding genes, of which 365 carbohydrate-active enzyme (CAZyme)-coding genes and 19 biosynthetic gene clusters (BCGs) for secondary metabolites were identified. Comparative transcriptomic and proteomic analysis revealed a global view of differential metabolic change between seed and fermentation culture, and demonstrated positive correlations between transcription and expression levels of 157 differentially expressed genes involved in the metabolism of amino acids, fatty acids, secondary metabolites, antioxidant and immune responses. Facilitated by the widely targeted metabolomic approach, a total of 307 secondary substances were identified and quantified, with a significant increase in the production of antioxidant polyphenols. CONCLUSION: This study provided the comprehensive analysis of the fungus Inonotus obliquus, and supplied fundamental information for further screening of promising target metabolites and exploring the link between the genome and metabolites.

Physiological changes and gene responses during Ganoderma lucidum growth with selenium supplementation.

Ganoderma lucidum basidiomycota is highly appreciated for its health and nutrition value. In the present study, Ganoderma lucidum was cultivated as selenium transformation carrier, and the physiological changes and gene responses by selenium supplementation were revealed through high-throughput RNA-Seq technology. As a result, selenium supplementation increased the stipe length and the cap size, but decreased the cap thickness of G. lucidum. Mineral salt supplementation could greatly promote the formation of triterpene acids and selenium in G. lucidum. The highest yield was gained in the treatment with selenium content of 200 µg/g. Subsequently, the tissues of G. lucidum at budding and mature stages in this treatment group were sampled for transcriptome analysis and compared to those of a control group without selenium supplementation. A total of 16,113 expressed genes were obtained from the transcriptome of G. lucidum, and GO-annotated unigenes were mainly involved in molecular functions and KEGG-annotated ones were highly expressed in ribosomal pathway. Furthermore, genes involved in carbon metabolism pathway were most promoted by selenium at budding stage of G. lucidum, while gene expression was the highest in the pathway of amino acid biosynthesis at mature stage of G. lucidum. Specially, selenium-related genes in G. lucidum, such as GL23172-G, GL29881-G and GL28298-G, played a regulatory role in oxidoreductase, antioxidant activity and tryptophan synthesis. The results provide a theoretical basis for further study of selenium-enriched mushrooms and aid to development of Se-enriched foodstuff and health products made from fungi.

Pulsed Light Mutagenesis of the Willow Bracket Mushroom, Phellinus igniarius (Agaricomycetes), for Enhanced Production of Flavonoids, Laccase, and Fermentation Biomass.

Phellinus igniarius is a medicinal fungus possessing potent therapeutic activity due to the polysaccharides, polyphenols, flavonoids, and other secondary metabolites they contain. Laccases are crucial enzymes involved in lignin degradation in Ph. igniarius and offer great potential to accomplish several bioprocesses. To generate Ph. igniarius strains with high biomass, flavonoid, and laccase activity, we used pulsed light (PL) technology for mutagenesis of Ph. igniarius protoplasts and screened for mutants with high biomass, flavonoid, and laccase activity. At the irradiation power of 100 J, treated distance 8.5 cm, irradiation frequency was 0.5 s/time, three times treatments, after five generations of selection, three mutants were obtained with higher biomass production. Compared with control, the mycelium biomass and the flavonoid production of the screened mutant strain QB72 were increased 20.87% and 53.51%, respectively. The total amount of the accumulated extracellular laccase of the QB72 in the first 6 and 8 days increased 23.38% and 22.37% respectively, and over the total 16 days it increased 9.62%. In addition, RAPD analysis results indicated that the genetic materials of the mutant QB72 were altered. PL mutagenesis method has great potential for developing strains, especially Phellinus.

Chromosome-Level Genome Sequences, Comparative Genomic Analyses, and Secondary-Metabolite Biosynthesis Evaluation of the Medicinal Edible Mushroom Laetiporus sulphureus.

Laetiporus sulphureus mushroom is a complementary and alternative medicine that has anticancer, antioxidation, and analgesic effects and immunomodulatory activity; it is used as a treatment for cough and rheumatism and is a functional food that can improve physical fitness. Even though L. sulphureus has garnered considerable biotechnological and pharmacological interest due to its excellent cellulose-degrading ability and diverse biological activities, its biosynthetic potential regarding polysaccharides and secondary metabolites has not been thoroughly examined. In this study, we sequenced and assembled the whole genome of a wild L. sulphureus isolate, NWAFU-1, from the Qinling Mountains in China. Comparative genomes analysis revealed genomic differences between subspecies, and phylogenomic analysis revealed evolutionary divergence as well as genome expansion and contraction of individual Polyporaceae family species. Bioinformatics investigation identified candidate genes associated with mating type, polysaccharide synthesis, carbohydrate-active enzymes, and secondary-metabolite biosynthesis, which included multiple terpenoids, nonribosomal peptides, and polyketides. The locations of biosynthetic core genes were mapped and displayed on chromosomes and contigs. Totals of 143 proteins from 126 coding genes were identified and divided into 14 cytochrome P450 families. Furthermore, the biosynthetic network of tetracyclic triterpenoid active components was postulated by genome mining of related genes combined with the molecular network of metabolites. The genome analysis of L. sulphureus in this study improves the understanding of the biosynthesis of active compounds, which will lay a theoretical foundation for subsequent research on active-compound biosynthesis and promote the application of Laetiporus in the field of drug research and functional-food creation. IMPORTANCE L. sulphureus is a parasitic basidiomycete fungus that causes brown rot. The fruiting bodies of L. sulphureus are used as ancient medicines in China and Europe to cure cancer, analgesia, cough, and rheumatism and are considered a functional food that regulates the body and improves health. L. sulphureus was inferred to be a tetrapolar system based on a high-quality genome, which will aid molecular breeding and artificial farming. Screening polysaccharide synthesis candidate genes and comparing carbohydrate-associated genes in brown-rot basidiomycetes help understand their growth. Identifying core genes for secondary-metabolite biosynthesis, gene cluster family analysis, and comparative cluster analysis will guide heterologous-biosynthesis investigations of these genes and help elucidate the biosynthetic pathways for L. sulphureus bioactive natural components. The biosynthesis network of tetracyclic triterpenes was mapped using metabolite profiling and genome scanning. This work explores the biosynthetic capacity of L. sulphureus-derived natural products and lays the foundation for biosynthetic studies of them.

Biochemical and transcriptomic analyses of the symbiotic interaction between Cremastra appendiculata and the mycorrhizal fungus Coprinellus disseminatus.

BACKGROUND: Cremastra appendiculata is a rare terrestrial orchid with a high market value as an ornamental and medicinal plant. However, the species depends entirely on fungi for seed germination under natural conditions. In a previous study, we have successfully isolated and identified the mycorrhizal fungus Coprinellus disseminatus which was able to induce the germination of C. appendiculata seeds. We then speculated that C. disseminatus may do so by breaking the testa imposed dormancy of the seeds. In this study, biochemical and transcriptomic analyses were used to characterize the germination of C. appendiculata seeds, collected at different stages of germination, as affected by C. disseminatus. RESULTS: The lignocellulose in the seeds coat of C. appendiculata was degraded by the mycorrhizal fungus resulting in facilitated absorption of water. The rate of decline in lignin content was 67 and 73% at 6 and 12 days after sowing, respectively. The water content increased from 13 to 90% during symbiosis. A total of 15,382 genes showing significantly different levels of expression (log2 FPKM≥2.0, Qvalue≤0.05) were successfully identified among all libraries, where the highest number of DEGs was shared between 6 days versus 0 day after symbiotic germination. Gene annotation results suggested that 15 key genes related water-status, such as DHN gene family and Xero 1 were down-regulated. The genes zeaxanthin epoxidase ZEP, 9-cis-epoxycarotenoid dioxygenase NCED3 and ß-carotene hydroxylase involved in the biosynthesis of abscisic acid (ABA) were significantly down-regulated in 6 days as compared to 0 day after symbiotic germination. CONCLUSIONS: This work demonstrates that mycorrhizal fungus C. disseminatus can stimulate C. appendiculata seeds germination through a mechanism of breaking the testa imposed dormancy and inducing water absorption of the embryo.

De Novo Transcriptome Analysis of the Willow Bracket Medicinal Mushroom Phellinus igniarius (Agaricomycetes) by RNA Sequencing.

Phellinus igniarius has been widely used as traditional herbal medicine in China, Korea, Japan, and other Asian countries for centuries. To gain a molecular understanding of this fungus, Illumina high-throughput technology was used to sequence and analyze the transcriptome of Ph. igniarius, and 11,847 unigenes were obtained. Additionally, based on similarity search with known proteins, unigenes were annotated with gene descriptions, gene ontology (GO), and clusters of orthologous groups (COG). Based on the GO annotation, a total of 6983 unigenes could be assigned to one or more terms, which were categorized into 39 functional groups under three main divisions (biological process, cellular component and molecular function). A total of 2315 Ph. igniarius unigenes were associated with 124 unique Kyoto Encyclopedia of Genes and Genomes pathways. A total of 832 simple sequence repeats were identified in these unigenes. In addition, nine candidate genes involved in laccases were discovered, 17 candidate genes involved in the biosynthesis of triterpenoid were identified and were worthy for further investigation. This is the first study to conduct transcriptome analyses on Ph. igniarius, which lays a basis for further functional genomics studies of Ph. igniarius.

Do the Main Components of the Sclerotia of Umbrella Polypore Mushroom, Polyporus umbellatus (Agaricomycetes), Correlate with Armillaria Associates?

Polyporus umbellatus is a traditional Chinese medicinal mushroom. The growth of P. umbellatus sclerotia requires the rhizomorphs of Armillaria spp. to supply nutrition. Whether the main components (MC) of sclerotia of P. umbellatus are related to the phylogeny of Armillaria associates or other environmental factors is largely unknown. In this study, we collected 17 sclerotia and soil samples from northeast to southwest China. In total, 17 Armillaria associates were isolated, and sclerotial MC contents and soil characteristics (total N, P, K, and organic matter) were determined. The analysis revealed that the MC content of P. umbellatus did not resemble a Brownian motion process in phylogeny of Armillaria associates, but were significantly influenced by the total N content of the soil. These results provide clear evidence that sclerotia of P. umbellatus associating with phylogenetic related Armillaria associates possess differing MC content. The mechanisms of nutrient exchange in P. umbellatus-Armillaria associations now require further elucidation.

Nutritional and Biochemical Characterization of Panus lecomtei Mushroom (Agaricomycetes) from India and Its Cultivation.

Panus lecomtei is emerging as an edible mushroom found worldwide and particularly in the Northern Hemisphere. The mushroom contains a substantial amount of useful nutritional and medicinal compounds. In the present study, we have examined a specimen of P. lecomtei submitted to the ICAR-Directorate of Mushroom Research gene bank. The specimen was examined for taxonomical characters using classical and molecular tools. Attempts were made for cultivation of this mushroom under controlled conditions using sawdust-based substrate. The specimen was characterized by its purplish fruiting body having coarse, rigid, dense hairs on the cap, pubescent stipe, and abundant metuloids. Molecular identification through conserved ITS region was done and the sequence was deposited in NCBI GenBank under accession number MN332200. Nutritional profiling and biochemical analysis showed that the mushroom contained high carbohydrate but low fat contents. The mushroom showed the presence of phenolics, ß-carotene, and lycopene. The analysis also showed substantial antioxidant properties in the mushroom. The findings presented herein point out that P. lecomtei can be used as a potential edible mushroom for diversification of mushroom production in India.

Genome sequencing and functional characterization of a Dictyopanus pusillus fungal enzymatic extract offers a promising alternative for lignocellulose pretreatment of oil palm residues.

The pretreatment of biomass remains a critical requirement for bio-renewable fuel production from lignocellulose. Although current processes primarily involve chemical and physical approaches, the biological breakdown of lignin using enzymes and microorganisms is quickly becoming an interesting eco-friendly alternative to classical processes. As a result, bioprospection of wild fungi from naturally occurring lignin-rich sources remains a suitable method to uncover and isolate new species exhibiting ligninolytic activity. In this study, wild species of white rot fungi were collected from Colombian forests based on their natural wood decay ability and high capacity to secrete oxidoreductases with high affinity for phenolic polymers such as lignin. Based on high activity obtained from solid-state fermentation using a lignocellulose source from oil palm as matrix, we describe the isolation and whole-genome sequencing of Dictyopanus pusillus, a wild basidiomycete fungus exhibiting ABTS oxidation as an indication of laccase activity. Functional characterization of a crude enzymatic extract identified laccase activity as the main enzymatic contributor to fungal extracts, an observation supported by the identification of 13 putative genes encoding for homologous laccases in the genome. To the best of our knowledge, this represents the first report of an enzymatic extract exhibiting laccase activity in the Dictyopanus genera, offering means to exploit this species and its enzymes for the delignification process of lignocellulosic by-products from oil palm.

Medicinal Properties of Clitocybe brunneocaperata (Agaricomycetes) from India.

The present research documented the first evidence of Clitocybe brunneocaperata from Tripura, Northeast India. The main purposes of this study were identification of the mushroom and qualitative toxicity screening along with antibacterial and antioxidant activities of its methanolic extracts. The species has been recognized on the basis of the morphometric and molecular studies. Toxicity test revealed its inedibility nature. Methanolic extracts of C. brunneocaperata showed potent antibacterial, free radical scavenging effect (65.42%), chelating effects on ferrous ion (65.93%), total phenolic content (0.028 mg GAE/g), and flavonoid content (0.013 mg CE/g). The lowest EC50 values of the free radical scavenging effect (5.94 mg/ml) and chelating effects on ferrous ion (0.072 mg/ml) were observed at 16 and 1.5 mg/ml concentrations, respectively, which implied stronger capability of free radical scavenging. Therefore, further research is also required to isolate and characterize the principal components of C. brunneocaperata.

Rare Fungal Keratitis Caused by Coprinellus Radians.

A case of fungal keratitis due to Coprinellus radians is reported. To our knowledge, fungal keratitis caused by this species was rare. Fungal hyphae were detected in corneal scrapings, and isolates were identified by morphology and by sequencing the internal transcribed spacer region of ribosomal DNA. The patient was treated with systemic and local antifungal therapy for 5 days, and lamellar keratoplasty was performed after no obvious improvement in symptoms. The in vitro antifungal susceptibilities of the case strain were tested for six antifungal agents. The results showed that 5-fluorouracil was resistant, fluconazole was moderately sensitive, and the other drugs assayed (amphotericin B, posaconazole, itraconazole and voriconazole) were highly effective against this fungus.

Enhanced Cordycepin Production in Caterpillar Medicinal Mushroom, Cordyceps militaris (Ascomycetes), Mutated by a Multifunctional Plasma Mutagenesis System.

A multifunctional plasma mutation system (MPMS) method was used to create high cordycepin-yielding mutations from wild Cordyceps militaris, which yielded many viable mutants, many of which produced more cordycepin compared to the wild strain. One particular mutant strain (GYS60) produced 7.883 mg/mL, which is much higher than those reported to date and is more than 20 times higher than that of the wild strain, whereas the cordycepin production of another viable mutant (GYS80) was almost zero. The extraction and purification of cordycepin, using the fermentation broth of C. militaris GYS60, was also investigated. Cordycepin was extracted by using AB-8 macroporous resin and purified by using reversed-phase column chromatography. When the sample was adsorbed onto the macroporous resin, 20% ethanol was used as the desorption solvent yielding various fractions. The fractions containing cordycepin were loaded onto a reversed-phase chromatography column packed with octadecyl bonded silica as the stationary phase and ethanol (95%)/acetic acid solution (5%) at pH 6.0 as the mobile phase. The combination of this two-step extraction-purification process yielded cordycepin at 95% purity with a total recovery rate of 90%.

Professor Shu-Ting Chang on His 90th Birthday.

This issue is dedicated to the 90th birthday of Professor Shu-Ting Chang, a prominent scientist in the field of mushroom biology, including cultivation and nutritional values of mushrooms, medicinal mushroom science, and environmental impact of mushrooms. Professor Shu-Ting Chang is also one of the initiators and has been an editor of our journal from its inception (in 1999) until now.

Quantification of Mushroom-Derived Soluble ß-1,6-Glucan Using the Function-Modified Recombinant ß-1,6-Glucanase.

Mushroom is one of the major sources of ß-glucan used in medical applications and traditional therapies. Thus, structure analysis and quantification of ß-glucan content is crucial to evaluate medicinal mushrooms. Most studies concerning mushroom-derived ß-glucan have been focused on ß-1,3-glucans. However, recent investigations suggest that ß-1,6 glucans have important roles for immunomodulating activity. Therefore, to elucidate the fine structure of various mushroom-derived ß-glucans, we recently developed a novel ß-1,6 glucan detection system using the function-modified recombinant ß-1,6-glucanase. In this study, we performed an ELISA-like assay using modified ß-1,6-glucanase and soluble dectin-1-Fc as the probes for ß-1,6-glucan and ß-1,3-glucan, respectively. Reactivity of ELISA to crude hot water extracts of edible mushrooms (Grifola frondosa, Agaricus bisporus, Pleurotus tuoliensis, P. eryngii, P. ostreatus, Hypsizygus marmoreus, and Lentinus edodes) was compared and L. edodes showed the strongest reactivity among them. An additional 19 different products of fresh L. edodes (shiitake mushroom) commercially available in Japan were also analyzed. This revealed limited differences in amounts of ß-1,6-glucan and ß-1,3-glucan in each shiitake mushroom. Furthermore, structural analysis of some purified ß-glucans derived from medicinal mushrooms was performed, and their action for inducing tumor necrosis factor-α production from the murine bone marrow-derived dendritic cells was investigated. We found relation between reactivity to modified ß-1,6-glucanase and its cytokine inducing activity. This assay could be useful for evaluating the strains of edible or medicinal mushrooms, which may be used as alternative medicines.

Immunoregenerative effects of the bionically cultured Sanghuang mushrooms (Inonotus sanghuagn) on the immunodeficient mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Description of the pharmacological activities of Sanghuang mushrooms (Inonotus Sanghuang) can be traced back to Tang dynasty of China 1300 years ago. This mushroom has been widely accepted in China, Japan, Korea and certain regions of Europe as a nutraceutical medicine for enhancing immunity or an alternative medicine for prevention or inhibition of tumorigenesis. However, this mushroom is rarely available from the mulberry trees in the wild because of the rigorous conditions needed for formation of the Sanghuang mushrooms. AIM OF THE STUDY: This study aims to establish a practical protocol for culture, particularly for a bunch of production of Sanghuang mushrooms possibly to commercialize the cultured Sanghuang based on deep comparison of quality and pharmacological activities between the cultured and the wild Sanghuang. MATERIALS AND METHODS: A phylogenetic tree containing five strains of the wild Sanghuang was constructed using rDNA markers. Different temperatures and medium compositions were surveyed to develop a practical protocol for culture of the Sanghuang mushrooms. 5-fluorouracil was used to induce the immunodeficient mice. Chemotherapeutic components and pharmacological activities were deeply analyzed between a cultured strain (SG) and three strains of the wild Sanghuang. RESULTS: Maintenance of a temperature of 22-28 °C and a high relative humidity of 90-95%, and use of a high ratio (80%) of mulberry tree sticks in the medium were critical to successful culture of Sanghuang. The cultured mushrooms were yellow with a uniform shape, while the wild Sanghuang was dark brown with a smaller and irregular shape. The cultured mushrooms contained significantly higher levels of polysaccharides, amino acids, and water-soluble nutraceuticals, whereas flavones in the wild Sanghuang were significantly higher (P < 0.05). Use of a dose of 8 mg/kg or 16 mg/kg to immunoregenerate the immunodeficient mice was comparable between the cultured and wild Sanghang based on analysis of hematological parameters and histological examination of the thymus and spleen in the treated mice. CONCLUSIONS: This study highlights the potential of the immunoregenerative functions of the cultured Sanghuang for cancer chemotherapy and suggests that the cultured Sanghuang can be an alternative to wild Sanghuang used for nutraceutical medicine.

Transcriptional profiling of Auricularia cornea in selenium accumulation.

Auricularia cornea is a widely cultivated edible fungus with substantial nutritive value. This study aimed to enrich the multifunctional bionutrient element selenium in A. cornea to improve its quality and explore the accumulation of selenium in the fungus using high-throughput RNA-Seq technology. In general, the treatment group with a 100 µg/g supply of selenium outperformed the other treatment groups in terms of high yield, rich crude polysaccharides and a high total selenium concentration. Additional evidences demonstrated the budding and mature phases were two typical growth stages of A. cornea and were important for the accumulation of selenium. Therefore, the budding and mature phase tissues of A. cornea in the treatment group with a 100 µg/g supply of selenium were used for transcriptome analysis and compared to those of a control group that lacked additional selenium. A total of 2.56 × 105 unigenes from A. cornea transcriptome were assembled and annotated to five frequently used databases including NR, GO, KEGG, eggNOG and SwissProt. GO and KEGG pathway analysis revealed that genes involved in metabolic process and translation were up-expressed at the budding stage in response to selenium supplementation, including amino acid metabolism, lipid metabolism, ribosome. In addition, the differential gene expression patterns of A. cornea suggested that the up-expressed genes were more likely to be detected at the budding stage than at the mature stage. These results provide insights into the transcriptional response of A. cornea to selenium accumulation.

Analysis of Intraspecies Genetic Variability among Collections of Medicinal Red Belt Conk Mushroom, Fomitopsis pinicola (Agaricomycetes).

Intraspecies genetic variability of the medicinal dikaryotic polypore mushroom Fomitopsis pinicola was analyzed by using variable internal transcribed space (ITS) region of the ribosomal DNA gene cluster and the somatic compatibility test. The results revealed very low ITS sequence polymorphism among strains of F. pinicola from geographically distant origins (Russia, Finland, and France). Because of its conserved structure, the ITS region of the ribosomal DNA cluster can be proposed as a reliable molecular code for identifying and taxonomically verifying F. pinicola sensu stricto species. Four types of somatic incompatibility interactions were found in the Moscow population; 29 dikaryotic isolates revealed 27 somatically incompatible groups with an overall diversity index (HVC) of 0.782. Moderate antagonistic (somatically incompatible) interactions were predominant, with a frequency (p) of 0.56; strong antagonism with the heavily pigmented interaction zone was estimated as p = 0.35. These findings regarding the genetic diversity of natural F. pinicola isolates will assist further research and development of novel strains useful in food, medicine, and industrial applications.

Phytogeographical and sociolinguistical patterns of the diversity, distribution, and uses of wild mushrooms in Côte d'Ivoire, West Africa.

BACKGROUND: Many fungal species in tropical Africa are useful, with high added value, and play essential roles in the structure and dynamic of ecosystems. However, the diversity, distribution, and uses by local populations of these non-timber forest products (NTFPs) and their respective habitats are still very poorly understood in sub-Saharan Africa in general and more specifically in Côte d'Ivoire. This study aims at (i) inventorying the wild useful mushrooms of Côte d'Ivoire within its major protected areas and their respective surrounding sociolinguistical groups, according to climatic and phytogeographical gradients, and (ii) recording ethnomycological knowledge and considerations of these local people. METHODS: Field and ethnomycological surveys were conducted in the main and highest protected areas of Côte d'Ivoire (Comoé, Marahoué, and Taï national parks) and a set of their respective surrounding villages, along climatic and phytogeographical gradients. Standardized methods (permanent plots and opportunistic searches) were used for field surveys. In addition, a total 748 respondents belonging to 13 ethnic groups were interviewed at a rate of 300 interviewees during the preliminary investigations and 448 persons during the proper ethnomycological surveys. RESULTS: Sixty-eight useful wild fungal species, belonging to 17 families and 23 genera, were listed and collected. Four categories of usage were reported by the rural people (food, medicinal, belief and recreational), with a dominance of food and medicinal uses. Fifty-six species were reported to be used as food and 16 species as medicinal fungi. These uses varied not only from one sociolinguistical group to another but also from a visited village to another. The high number (41) of the reported useful species was found in the Sudano-Guinean savanna zone while 28 species were collected in the forest zone and 22 species in the forest-savanna mosaic zone. These mushrooms were either saprotrophic or symbiotic (ectomycorrhizal or termitophilic). Auricularia sp3, Psathyrella tuberculata, and Termitomyces spp. were found as the most commonly used mushrooms. CONCLUSIONS: These national scale field and ethnomycological surveys give one of the more complete but non-exhaustive list of useful mushrooms of Côte d'Ivoire. Mushrooms are relatively well known and used by the Ivorian people within the main phytogeographical zone of the country. These people also have an interest in all the functional groups with an important phytogeographical zone-fungal-specific used species. However, protected areas of the visited zones seem to represent the last sanctuaries of these organisms due to high rate of loss of natural habitats.