Bioluminescence patterns among North American Armillaria species

Armillaria altimontana in North America: Biology and Ecology

Armillaria altimontana is a fungus (Basidiomycota, Agaricomycetes, Agaricales, and Physalacriaceae) that is generally considered as a weak/opportunistic pathogen or saprophyte on many tree hosts. It widely occurs across the northwestern USA to southern British Columbia, Canada, but relatively little is known about its ecological role in the diverse forest ecosystems where it occurs. This review summarizes the biology and ecology of A. altimontana, including its identification, life cycle, distribution, host associations, and bioclimatic models under climate change.

The Luminous Fungi of Japan

Luminous fungi have long attracted public attention in Japan, from old folklore and fiction to current tourism, children's toys, games, and picture books. At present, 25 species of luminous fungi have been discovered in Japan, which correspond to approximately one-fourth of the globally recognized species. This species richness is arguably due to the abundant presence of mycophiles looking to find new mushroom species and a tradition of night-time activities, such as firefly watching, in Japan. Bioluminescence, a field of bioscience focused on luminous organisms, has long been studied by many Japanese researchers, including the biochemistry and chemistry of luminous fungi. A Japanese Nobel Prize winner, Osamu Shimomura (1928-2018), primarily focused on the bioluminescence system of luminous fungi in the latter part of his life, and total elucidation of the mechanism was finally accomplished by an international research team with representatives from Russia, Brazil, and Japan in 2018. In this review, we focused on multiple aspects related to luminous fungi of Japan, including myth, taxonomy, and modern sciences.

Roy, M. Firoz Ahmed. New distribution record of Roridomyces cf. phyllostachydis (Agaricales: Mycenaceae), a bioluminescent fungus from Namdapha National Park, Arunachal Pradesh, India

Nocturnal surveys conducted in Namdapha National Park of Arunachal Pradesh (India) in April 2022 led to an opportunistic encounter with bioluminescent fungi. Based on morphological characteristics and photographic comparisons from published literature, we have identified the species to be Roridomyces cf. phyllostachydis, a glowing mushroom that has previously been described from two different districts of Meghalaya (East Khasi Hills and West Jayantia Hills). The glowing stipe surface without the glowing pileus distinguishes this species from other bioluminescent fungal species found in India. Our observation of Roridomyces cf. phyllostachydis marks a new distribution record from the state of Arunachal Pradesh.

Resources of Iranian agarics (Basidiomycota) with an outlook on their antioxidant potential

Agaric fungi are an important group of macromycetes with diverse ecological and functional properties, yet are poorly studied in many parts of the world. Here, we comprehensively analyzed 558 agaric species in Iran to reveal their resources of edible and poisonous species as well as their ecological guilds and luminescence potential. We also made a thorough survey of the antioxidant activity of the species. Phylogenetic relationships were reconstructed based on nuclear ribosomal LSU and ITS sequences. Our results reveal that agarics of Iran comprise about 189 edible, 128 poisonous, 254 soil saprotrophic, 172 ectomycorrhizal, 146 wood-inhabiting, 18 leaf/litter-inhabiting, 9 parasitic, and 19 luminescent species. Twenty percent of the Iranian agaric species possess antioxidant activity, phylogenetically distributed in four orders and 21 agaric families. About 5% of the antioxidant species can be considered strong antioxidants, many of which are also edible and could be utilized to develop functional foods. This is the first study combining phylogeny and antioxidant potential of agaric mushrooms in a large scale, and the obtained results would guide the selection of agaric taxa to be examined in the future for taxonomic revisions, biotechnological applications, and applied phylogeny studies.

Mycena genomes resolve the evolution of fungal bioluminescence

Mushroom-forming fungi in the order Agaricales represent an independent origin of bioluminescence in the tree of life; yet the diversity, evolutionary history, and timing of the origin of fungal luciferases remain elusive. We sequenced the genomes and transcriptomes of five bonnet mushroom species (Mycena spp.), a diverse lineage comprising the majority of bioluminescent fungi. Two species with haploid genome assemblies ∼150 Mb are among the largest in Agaricales, and we found that a variety of repeats between Mycena species were differentially mediated by DNA methylation. We show that bioluminescence evolved in the last common ancestor of mycenoid and the marasmioid clade of Agaricales and was maintained through at least 160 million years of evolution. Analyses of synteny across genomes of bioluminescent species resolved how the luciferase cluster was derived by duplication and translocation, frequently rearranged and lost in most Mycena species, but conserved in the Armillaria lineage. Luciferase cluster members were coexpressed across developmental stages, with the highest expression in fruiting body caps and stipes, suggesting fruiting-related adaptive functions. Our results contribute to understanding a de novo origin of bioluminescence and the corresponding gene cluster in a diverse group of enigmatic fungal species.

New species and records of bioluminescent Mycena from Mexico

Seven species of bioluminescent fungi are recorded from the cloud forests in Mexico. Six represent new species belonging to the genus Mycena, whereas Mycena globulispora is a new distribution record for the country. Descriptions, illustrations, photographs, and an identification key to bioluminescent fungi species from Mexico are provided. Sequences of nuc rDNA internal transcribed spacer (ITS1-5.8S-ITS2 = ITS) region were generated for barcoding purposes and comparisons with similar species.

Allelopathy of Wild Mushrooms—An Important Factor for Assessing Forest Ecosystems in Japan

Research Highlights: Some organisms such as plants and fungi release certain secondary metabolites, generally called allelochemicals, which can influence the organisms around them. Some of the secondary metabolites released by mushrooms may have certain effects on the growth and development of neighboring plants. Background Objectives: The purpose of the present study was to investigate the allelopathic potential of mushrooms in a forest ecosystem. To this end, 289 Japanese mushroom species were collected from the wild and tested using a modified sandwich method, which is a quick and effective bioassay technique. Materials and Methods: The collected specimens were prepared for bioassay as dried samples, and 10 mg/well (10 cm2) was added to a 6-well multidish according to the mycelia biomass, which was estimated at 700−900 kg ha−1 year−1 (7–9 mg 10 cm−2) in coniferous forests. Results: Of the screened mushroom species, 74% inhibited more than 50% of the radicle elongation in lettuce (Lactuca sativa var. Great Lakes 366) seedlings, while the average of all species was 41.1%. This result suggests that wild mushrooms have a significant regulatory effect on lettuce growth. According to our standard deviation variance analysis, 54 out of 289 species showed significant allelopathic activity. Among these species, Xeromphalina tenuipes, Cortinarius violaceus, and Clavaria miyabeana exhibited the strongest growth inhibitory activity, with radicle elongation of 5.1%, 4.3%, and 7.6% of the control, respectively. In contrast, Ischnoderma resinosum stimulated the length of radicle and hypocotyl growth by 30.6% and 42.0%, respectively. These results suggest that these species may play important roles in ecosystems. In addition, the wide range of allelopathic activities observed in mushrooms indicates that various amounts of diverse secondary metabolites from these species are involved in mushroom allelopathy. Conclusions: Our study reveals the importance of evaluating mushroom allelopathy to understand the wider ecological structures within complex ecosystems.

Bioluminescence expression during the transition from mycelium to mushroom in three North American Armillaria and Desarmillaria species

Unlike most bioluminescent fungi, mycelia of Armillaria and Desarmillaria are constitutively bioluminescent while mature mushrooms are not. The absence of the luciferin, 3-hydroxyhispidin, and its precursor hispidin in mature mushrooms have been proposed to explain the lack of bioluminescence from Armillaria mushrooms. Using three North American species, A. gallica, A. mellea and D. tabescens (syn., Armillaria tabescens), we documented a decline in luminescence of ten fold during the transition from mycelia to, immature mushrooms (i.e., pins) for the two Armillaria species. As pins matured, luminescence declined by an additional two or three orders of magnitude. Lower initial luminescence of D. tabescens mycelia declined to negligible levels during mushroom development. Further, light production was localized in the gills and lower stipe of A. mellea mushrooms. The decline in luminescence during mushroom formation was reversed by addition of hispidin to stipe or gills which significantly enhanced luminescence by one and three orders of magnitude, respectively. We conclude that the modulation of Armillaria and Desarmillaria luminescence is achieved by luciferin availability early in mushroom development. However, since the temporal regulation of bioluminescence differs between Armillaria species and other genera, we conclude that bioluminescence in Armillaria is under unique selective pressures.

The good, the bad and the tasty: The many roles of mushrooms

Fungi are often inconspicuous in nature and this means it is all too easy to overlook their importance. Often referred to as the "Forgotten Kingdom", fungi are key components of life on this planet. The phylum Basidiomycota, considered to contain the most complex and evolutionarily advanced members of this Kingdom, includes some of the most iconic fungal species such as the gilled mushrooms, puffballs and bracket fungi. Basidiomycetes inhabit a wide range of ecological niches, carrying out vital ecosystem roles, particularly in carbon cycling and as symbiotic partners with a range of other organisms. Specifically in the context of human use, the basidiomycetes are a highly valuable food source and are increasingly medicinally important. In this review, seven main categories, or 'roles', for basidiomycetes have been suggested by the authors: as model species, edible species, toxic species, medicinal basidiomycetes, symbionts, decomposers and pathogens, and two species have been chosen as representatives of each category. Although this is in no way an exhaustive discussion of the importance of basidiomycetes, this review aims to give a broad overview of the importance of these organisms, exploring the various ways they can be exploited to the benefit of human society.