Phylogeny and taxonomy of Echinodontium and related genera

Rapid detection of Heterobasidion annosum using a loop-mediated isothermal amplification assay

Heterobasidion annosum is one of the most aggressive pathogens of Pinus forests in Europe, causing considerable economic losses. To detect H. annosum for disease diagnosis and control, we developed a loop-mediated isothermal amplification (LAMP) reaction with a primer set designed from the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) DNA sequences of H. annosum. In our study, this LAMP assay was found to be capable of efficiently amplifying the target gene within 60 min at 63°C. In specificity tests, H. annosum was positively detected, and other species were negative. The detection limit of this assay was found to be 100 pg·μL^-1, and the assay was also successfully tested for use with basidiospore suspensions and wood samples. This study provides a rapid method for diagnosing root and butt rot caused by H. annosum, which will be of use in port surveillance of logs imported from Europe.

Isolation and characterization of an anti-proliferative polysaccharide from the North American fungus Echinodontium tinctorium

A novel polysaccharide EtGIPL1a was purified from fruiting bodies of Echinodontium tinctorium, a fungus unique to western North America. EtGIPL1a has an estimated weight average molecular weight of 275 kDa and is composed of glucose (54.3%), galactose (19.6%), mannose (11.1%), fucose (10.3%), glucuronic acid (4%), and rhamnose (0.6%). It has multiple glycosidic linkages, with 3-Glcp (28.9%), 6-Glcp (18.3%), 3,6-Glcp (13%), 4-GlcpA (9.2%), 6-Galp (3.9%), 2,6-Galp (2.6%), 3-Fucp (2.5%), 6-Manp (2.4%) being the most prominent, and unsubstituted glucose (15.3%), mannose (1.3%) and fucose (0.9%) as major terminal sugars. EtGIPL1a has a backbone containing mostly 3-substituted β-glucopyranose with 4-substituted glucopyranosyluronic acid. EtGIPL1a showed anti-proliferative activity against multiple cancer cell lines, with IC₅₀ ranging from 50.6 to 1446 nM. Flow cytometry analyses confirmed that apoptosis induction is one mechanism for its anti-proliferative activity. EtGIPL1a should be further investigated for its potential anti-cancer activity in animal models, and for its possible utility in differentiation cancer therapy.

Genome Sequencing and Analysis of the Fungal Symbiont of Sirex noctilio, Amylostereum areolatum: Revealing the Biology of Fungus-Insect Mutualism

Sirex noctilio (F.), together with Amylostereum areolatum, a wood-decaying symbiotic fungus, causes severe damage to Pinus species worldwide. In China, it causes extensive death of Mongolian pine (Pinus sylvestris var. mongolica). There is an obligate dependency mutualism between the woodwasp and its fungus. Studies have suggested that the fungal growth rate affected the size of the wasps: larger adults emerged from sites with a higher fungus growth rate. This genome is the first reported genome sequence of a woodwasp symbiotic fungus. Genome sequence analysis of this fungus would prove the possibility of A. areolatum volatiles affecting the host selection of S. noctilio on a molecular basis. We further clarified that A. areolatum was a strict obligate symbiotic fungus and that it would provide S. noctilio with a suitable environment and with nutrients for the larval growth. These results would lay a foundation for our understanding of the mechanism of this entomogenous symbiosis.

Amylostereum areolatum is the symbiotic fungus of the Eurasian woodwasp, Sirex noctilio, a globally invasive species. The mutualistic symbiont is associated with the woodwasp, assisting the damage process and providing nutrition for its insect partners. Colonization and growth of A. areolatum have essential impacts on the development and spread of S. noctilio, though the mechanism of interaction between the two has been poorly described. In this study, the first genome of this symbiotic fungus was sequenced, assembled, and annotated. The assembled A. areolatum genome was 57.5 Mb (54.51% GC content) with 15,611 protein-coding genes. We identified 580 carbohydrate-active enzymes (CAZymes), 661 genes associated with pathogen-host interactions, and 318 genes encoding transport proteins in total. The genome annotation revealed 10 terpene/phytoene synthases responsible for terpenoid biosynthesis, which could be classified into three clades. Terpene synthase gene clusters in clade II were conserved well across Russulales. In this cluster, genes encoding mevalonate kinase (MK), EGR12 (COG1557), and nonplant terpene cyclases (cd00687) were the known biosynthesis and regulatory genes. Genome sequence analysis of this fungus would prove the possibility of A. areolatum volatiles affecting the host selection of S. noctilio on a molecular basis. We further clarified that A. areolatum was a strict obligate symbiotic fungus. The wasps might protect the fungus before it was introduced into a suitable host substrate by oviposition, while the fungus would provide S. noctilio with a suitable environment and nutrients for the larval growth. These results would lay a foundation for our understanding of the mechanism of this entomogenous symbiosis.

IMPORTANCESirex noctilio (F.), together with Amylostereum areolatum, a wood-decaying symbiotic fungus, causes severe damage to Pinus species worldwide. In China, it causes extensive death of Mongolian pine (Pinus sylvestris var. mongolica). There is an obligate dependency mutualism between the woodwasp and its fungus. Studies have suggested that the fungal growth rate affected the size of the wasps: larger adults emerged from sites with a higher fungus growth rate. This genome is the first reported genome sequence of a woodwasp symbiotic fungus. Genome sequence analysis of this fungus would prove the possibility of A. areolatum volatiles affecting the host selection of S. noctilio on a molecular basis. We further clarified that A. areolatum was a strict obligate symbiotic fungus and that it would provide S. noctilio with a suitable environment and with nutrients for the larval growth. These results would lay a foundation for our understanding of the mechanism of this entomogenous symbiosis.

Anti-Inflammatory Activity of the Wild Mushroom, Echinodontium tinctorium, in RAW264.7 Macrophage Cells and Mouse Microcirculation

The aim of this study was to investigate the anti-inflammatory activity of a previously un-studied wild mushroom, Echinodontium tinctorium, collected from the forests of north-central British Columbia. The lipopolysaccharide (LPS)-induced RAW264.7 macrophage model was used to study the in vitro anti-inflammatory activity. The crude alkaline extract demonstrated potent anti-inflammatory activity, and was further purified using a "bio-activity-guided-purification" approach. The size-exclusion and ion-exchange chromatography yielded a water-soluble anti-inflammatory polysaccharide (AIPetinc). AIPetinc has an average molecular weight of 5 kDa, and is a heteroglucan composed of mainly glucose (88.6%) with a small amount of galactose (4.0%), mannose (4.4%), fucose (0.7%), and xylose (2.3%). In in vivo settings, AIPetinc restored the histamine-induced inflammatory event in mouse gluteus maximus muscle, thus confirming its anti-inflammatory activity in an animal model. This study constitutes the first report on the bioactivity of Echinodontium tinctorium, and highlights the potential medicinal benefits of fungi from the wild forests of northern British Columbia. Furthermore, it also reiterates the need to explore natural resources for alternative treatment to modern world diseases.

Four new corticioid species in Trechisporales (Basidiomycota) from East Asia and notes on phylogeny of the order

Four new species in Trechisporales from East Asia, Dextrinocystiscalamicola, Subulicystidiumacerosum, S.tropicum and Tubuliciumbambusicola, are described and illustrated, based on morphological and molecular evidence. The phylogeny of Trechisporales was inferred from a combined dataset of ITS-nrLSU sequences. In the phylogenetic tree, Sistotremastrum formed a family-level clade of its own, sister to the Hydnodontaceae clade formed by all other genera. Dextrinocystis, is for the first time, confirmed as a member of Hydnodontaceae. A key to all the accepted genera in Trechisporales is given.

Taxonomy and phylogeny of Dichostereum (Russulales), with descriptions of three new species from southern China

Nine species of Dichostereum were subjected to phylogenetic analyses, based on a combined dataset of ITS1-5.8S-ITS2-nrLSU-tef1 sequences. The morphology of specimens collected from China and Australia were studied. Three species, D.austrosinense, D.boidinii and D.eburneum, collected from southern China, are described and illustrated as new to science, based on the morphological and molecular evidence. Dichostereumaustrosinense is characterised by the relatively large gloeocystidia (80-130 × 8-15 µm) and basidiospores (7.3-8 µm in diam.) with large warts and crests. Dichostereumboidinii is distinguished by its thick basidiomata and relatively small basidiospores (5.5-6.5 µm in diam.) with large warts and crests. Dichostereumeburneum is unique in having pale basidiomata growing on bark of living Castanopsis, abundant crystals in the context and basidiospores with dense and large ornamentations. A key to the 5 species of Dichostereum in China is given.