Genomic Analysis of Sarcomyxa edulis Reveals the Basis of Its Medicinal Properties and Evolutionary Relationships

Evolution and related pathogenic genes of Pseudodiploöspora longispora on Morchella based on genomic characterization and comparative genomic analysis

True morels (Morchella) are globally renowned medicinal and edible mushrooms. White mold disease caused by fungi is the main disease of Morchella, which has the characteristics of wide incidence and strong destructiveness. The disparities observed in the isolation rates of different pathogens indicate their varying degrees of host adaptability and competitive survival abilities. In order to elucidate its potential mechanism, this study, the pathogen of white mold disease from Dafang county, Guizhou Province was isolated and purified, identified as Pseudodiploöspora longispora by morphological, molecular biological and pathogenicity tests. Furthermore, high-quality genome of P. longisporus (40.846 Mb) was assembled N50 of 3.09 Mb, predicts 7381 protein-coding genes. Phylogenetic analysis of single-copy homologous genes showed that P. longispora and Zelopaecilomyces penicillatus have the closest evolutionary relationship, diverging into two branches approximately 50 (44.3-61.4) MYA. Additionally, compared with the other two pathogens causing Morchella disease, Z. penicillatus and Cladobotryum protrusum, it was found that they had similar proportions of carbohydrate enzyme types and encoded abundant cell wall degrading enzymes, such as chitinase and glucanase, indicating their important role in disease development. Moreover, the secondary metabolite gene clusters of P. longispora and Z. penicillatus show a high degree of similarity to leucinostatin A and leucinostatin B (peptaibols). Furthermore, a gene cluster with synthetic toxic substance Ochratoxin A was also identified in P. longispora and C. protrusum, indicating that they may pose a potential threat to food safety. This study provides valuable insights into the genome of P. longispora, contributing to pathogenicity research.

Family matters inside the order Agaricales: systematic reorganization and classification of incertae sedis clitocyboid, pleurotoid and tricholomatoid taxa based on an updated 6-gene phylogeny

The phylogenetic position of several clitocyboid/pleurotoid/tricholomatoid genera previously considered incertae sedis is here resolved using an updated 6-gene dataset of Agaricales including newly sequenced lineages and more complete data from those already analyzed before. Results allowed to infer new phylogenetic relationships, and propose taxonomic novelties to accommodate them, including up to ten new families and a new suborder. Giacomia (for which a new species from China is here described) forms a monophyletic clade with Melanoleuca (Melanoleucaceae) nested inside suborder Pluteineae, together with the families Pluteaceae, Amanitaceae (including Leucocortinarius), Limnoperdaceae and Volvariellaceae. The recently described family Asproinocybaceae is shown to be a later synonym of Lyophyllaceae (which includes also Omphaliaster and Trichocybe) within suborder Tricholomatineae. The families Biannulariaceae, Callistosporiaceae, Clitocybaceae, Fayodiaceae, Macrocystidiaceae (which includes Pseudoclitopilus), Entolomataceae, Pseudoclitocybaceae (which includes Aspropaxillus), Omphalinaceae (Infundibulicybe and Omphalina) and the new families Paralepistaceae and Pseudoomphalinaceae belong also to Tricholomatineae. The delimitation of the suborder Pleurotineae (= Schizophyllineae) is discussed and revised, accepting five distinct families within it, viz. Pleurotaceae, Cyphellopsidaceae, Fistulinaceae, Resupinataceae and Schizophyllaceae. The recently proposed suborder Phyllotopsidineae (= Sarcomyxineae) is found to encompass the families Aphroditeolaceae, Pterulaceae, Phyllotopsidaceae, Radulomycetaceae, Sarcomyxaceae (which includes Tectella), and Stephanosporaceae, all of them unrelated to Pleurotaceae (suborder Pleurotineae) or Typhulaceae (suborder Typhulineae). The new family Xeromphalinaceae, encompassing the genera Xeromphalina and Heimiomyces, is proposed within Marasmiineae. The suborder Hygrophorineae is here reorganized into the families Hygrophoraceae, Cantharellulaceae, Cuphophyllaceae, Hygrocybaceae and Lichenomphaliaceae, to homogenize the taxonomic rank of the main clades inside all suborders of Agaricales. Finally, the genus Hygrophorocybe is shown to represent a distinct clade inside Cuphophyllaceae, and the new combination H. carolinensis is proposed. Taxonomic novelties: New suborder: Typhulineae Vizzini, Consiglio & P. Alvarado. New families: Aphroditeolaceae Vizzini, Consiglio & P. Alvarado, Melanoleucaceae Locq. ex Vizzini, Consiglio & P. Alvarado, Paralepistaceae Vizzini, Consiglio & P. Alvarado, Pseudoomphalinaceae Vizzini, Consiglio & P. Alvarado, Volvariellaceae Vizzini, Consiglio & P. Alvarado, Xeromphalinaceae Vizzini, Consiglio & P. Alvarado. New species: Giacomia sinensis J.Z. Xu. Stat. nov.: Cantharellulaceae (Lodge, Redhead, Norvell & Desjardin) Vizzini, Consiglio & P. Alvarado, Cuphophyllaceae (Z.M. He & Zhu L. Yang) Vizzini, Consiglio & P. Alvarado, Hygrocybaceae (Padamsee & Lodge) Vizzini, Consiglio & P. Alvarado, Lichenomphaliaceae (Lücking & Redhead) Vizzini, Consiglio & P. Alvarado. New combination: Hygrophorocybe carolinensis (H.E. Bigelow & Hesler) Vizzini, Consiglio & P. Alvarado. New synonyms: Sarcomyxineae Zhu L. Yang & G.S. Wang, Schizophyllineae Aime, Dentinger & Gaya, Asproinocybaceae T. Bau & G.F. Mou. Incertae sedis taxa placed at family level: Aphroditeola Redhead & Manfr. Binder, Giacomia Vizzini & Contu, Hygrophorocybe Vizzini & Contu, Leucocortinarius (J.E. Lange) Singer, Omphaliaster Lamoure, Pseudoclitopilus Vizzini & Contu, Resupinatus Nees ex Gray, Tectella Earle, Trichocybe Vizzini. New delimitations of taxa: Hygrophorineae Aime, Dentinger & Gaya, Phyllotopsidineae Zhu L. Yang & G.S. Wang, Pleurotineae Aime, Dentinger & Gaya, Pluteineae Aime, Dentinger & Gaya, Tricholomatineae Aime, Dentinger & Gaya. Resurrected taxa: Fayodiaceae Jülich, Resupinataceae Jülich. Citation: Vizzini A, Alvarado P, Consiglio G, Marchetti M, Xu J (2024). Family matters inside the order Agaricales: systematic reorganization and classification of incertae sedis clitocyboid, pleurotoid and tricholomatoid taxa based on an updated 6-gene phylogeny. Studies in Mycology 107: 67-148. doi: 10.3114/sim.2024.107.02.

Whole Genome Sequence of an Edible Mushroom Oudemansiella raphanipes (Changgengu)

Oudemansiella raphanipes, considered as a well-known culinary edible mushroom with a high content of natural bioactive substances, is widely cultivated in China with the commercial name Changgengu. However, due to the lack of genomic data, molecular and genetic study on O. raphanipes is rare. To obtain a comprehensive overview of genetic characteristics and enhance the value of O. raphanipes, two mating-compatible monokaryons isolated from the dikaryon were applied for de novo genome sequencing and assembly using Nanopore and /or Illumina sequencing platforms. One of the monokaryons, O. raphanipes CGG-A-s1, was annotated with 21,308 protein-coding genes, of which 56 were predicted to be involved in the biosynthesis of secondary metabolites such as terpene, type I PKS, NRPS, and siderophore. Phylogenetic and comparative analysis of multiple fungi genomes revealed a close evolutionary relationship between O. raphanipes and Mucidula mucid based on single-copy orthologous protein genes. Significant collinearity was detected between O. raphanipes and Flammulina velutipes on the synteny of inter-species genomes. 664 CAZyme genes in CGG-A-s1 were identified with GHs and AAs families significantly elevated when compared with the other 25 sequenced fungi, indicating a strong wood degradation ability. Furthermore, the mating type locus analysis revealed that CGG-A-s1 and CGG-A-s2 were conserved in the gene organization of the mating A locus but various in that of the mating B locus. The genome resource of O. raphanipes will provide new insights into its development of genetic studies and commercial production of high-quality varieties.

Comparative transcriptome and WGCNA reveal key genes involved in lignocellulose degradation in Sarcomyxa edulis

The developmental transcriptomes of Sarcomyxa edulis were assessed to explore the molecular mechanisms underlying lignocellulose degradation. Six stages were analyzed, spanning the entire developmental process: growth of mycelium until occupying half the bag (B1), mycelium under low-temperature stimulation after occupying the entire bag (B2), appearance of mycelium in primordia (B3), primordia (B4), mycelium at the harvest stage (B5), and mature fruiting body (B6). Samples from all six developmental stages were used for transcriptome sequencing, with three biological replicates for all experiments. A co-expression network of weighted genes associated with extracellular enzyme physiological traits was constructed using weighted gene co-expression network analysis (WGCNA). We obtained 19 gene co-expression modules significantly associated with lignocellulose degradation. In addition, 12 key genes and 8 kinds of TF families involved in lignocellulose degradation pathways were discovered from the four modules that exhibited the highest correlation with the target traits. These results provide new insights that advance our understanding of the molecular genetic mechanisms of lignocellulose degradation in S. edulis to facilitate its utilization by the edible mushroom industry.

Whole-genome assembly and analysis of a medicinal fungus: Inonotus hispidus

Inonotus hispidus (I. hispidus) is a medicinal macrofungus that plays a key role in anti-tumor and antioxidant functions. To further understand and enhance the value of I. hispidus, we performed whole-genome sequencing and an analysis of its strain for the first time. I. hispidus was sequenced using the Illumina NovaSeq high-throughput sequencing platform. The genome length was 35,688,031 bp and 30 contigs, with an average length of 1,189,601.03 bp. Moreover, database alignment annotated 402 CAZyme genes and 93 functional genes involved in regulating secondary metabolites in the I. hispidus genome to find the greatest number of genes involved in terpenes in that genome, thus providing a theoretical basis for its medicinal value. Finally, the phylogenetic analysis and comparative genomic analysis of single-copy orthologous protein genes from other fungi in the same family were conducted; it was found that I. hispidus and Sanghuangporus baumii have high homology. Our results can be used to screen candidate genes for the nutritional utilization of I. hispidus and the development of high-yielding and high-quality I. hispidus via genetic means.

Systematic analysis of changes across different developmental stages of the mushroom Sarcomyxa edulis

Sarcomyxa edulis is a widely harvested mushroom of Northeastern Asia. Its development can be divided into six stages: growth of mycelium until occupying half the bag (B1), mycelium under low-temperature stimulation after occupying the entire bag (B2), appearance of mycelium in primordia (B3), primordia (B4), mycelium at the harvest stage (B5), and mature fruiting body (B6). Differentially expressed gene (DEG) analysis and weighted gene coexpression network analysis (WGCNA) are important bioinformatic methods for screening key genes. To explore the growth and development mechanisms of the mushroom S. edulis and clarify its genetic background, DEG and WGCNA analyses were combined to screen key genes at different developmental stages. From A1 to A6, respectively, 459, 97, 885, 169, 277, and 712 key genes were identified. Then the Gene Ontology (GO) terms and KEGG pathways of key genes were analyzed, and GO and KEGG analyses were performed on all genes across different periods using GSEA. In summary, the genes in A1 were mainly involved in amino sugar and nucleotide sugar metabolism, structural molecule activity, and oxidative phosphorylation. At the A2 stage, genes were mainly involved in peptidase activity, peroxidase activity, oxidoreductase activity, antioxidant activity, biosynthesis of secondary metabolites, and glycolysis and gluconeogenesis. A3 genes were involved in gene expression, RNA metabolism, spliceosome, RNA transport, and ribosome biogenesis. A4 genes were mainly involved in the biosynthesis of secondary metabolites, proteasome complex, cellular protein complex assembly, actin filament-based processes, oxidative phosphorylation, and carbon metabolism. The A5 stage genes were involved in the carbohydrate metabolic process, polysaccharide metabolic process, and the biosynthesis of secondary metabolites, leucine, isoleucine, and ABC transporters. Finally, A6 genes were mainly involved in the cell cycle, meiosis of yeast, MAPK signaling pathway, cellular response to DNA damage stimulus, DNA metabolic process, DNA replication, and DNA repair. The combination of multiple analyses provides us with an in-depth understanding of the network that regulates mushroom development.