The family Nidulariaceae, consisting of five genera including Cyathus, is a unique group of mushrooms commonly referred to as bird’s nest fungi due to their striking resemblance to bird’s nests. These mushrooms are considered medicinal mushrooms in Chinese medicine and have received attention in recent years for their anti-neurodegenerative properties. However, despite the interest in these mushrooms, very little is known about their mitochondrial genomes (mitogenomes). This study is the first comprehensive investigation of the mitogenomes of five Nidulariaceae species with circular genome structures ranging in size from 114,236 bp to 129,263 bp. Comparative analyses based on gene content, gene length, tRNA, and codon usage indicate convergence within the family Nidulariaceae and heterogeneity within the order Agaricales. Phylogenetic analysis based on a combined mitochondrial conserved protein dataset provides a well-supported phylogenetic tree for the Basidiomycetes, which clearly demonstrates the evolutionary relationships between Nidulariaceae and other members of Agaricales. Furthermore, phylogenetic inferences based on four different gene sets reveal the stability and proximity of evolutionary relationships within Agaricales. These results reveal the uniqueness of the family Nidulariaceae and its similarity to other members of Agaricales; provide valuable insights into the origin, evolution, and genetics of Nidulariaceae species; and enrich the fungal mitogenome resource. This study will help to expand the knowledge and understanding of the mitogenomes in mushrooms.

Fusarium species are among the filamentous fungi with the most pronounced impact on agricultural production and human health. The mycotoxins produced by pathogenic Fusarium not only attack various plants including crops, causing various plant diseases that lead to reduced yields and even death, but also penetrate into the food chain of humans and animals to cause food poisoning and consequent health hazards. Although sporadic studies have revealed some of the biosynthetic pathways of Fusarium toxins, they are insufficient to satisfy the need for a comprehensive understanding of Fusarium toxin production. In this study, we focused on 35 serious pathogenic Fusarium species with available genomes and systematically analyzed the ubiquity of the distribution of identified Fusarium- and non-Fusarium-derived fungal toxin biosynthesis gene clusters (BGCs) in these species through the mining of core genes and the comparative analysis of corresponding BGCs. Additionally, novel sesterterpene synthases and PKS_NRPS clusters were discovered and analyzed. This work is the first to systematically analyze the distribution of related mycotoxin biosynthesis in pathogenic Fusarium species. These findings enhance the knowledge of mycotoxin production and provide a theoretical grounding for the prevention of fungal toxin production using biotechnological approaches.

Fusarium species are one of the filamentous fungal taxa with the most pronounced impact on agri-cultural production and human health. The mycotoxins produced by pathogenic Fusarium not on-ly attack various plants including crops, causing various plant diseases that lead to reduced yields and even death, but also penetrate into the food chain of humans and animals to cause food poi-soning and consequent health hazards. Although sporadic studies have revealed some of the bio-synthetic pathways of Fusarium toxins, they are insufficient to satisfy the need for a comprehen-sive understanding of Fusarium toxin production. In this study, we focused on 35 serious patho-genic Fusarium species with available genomes and systematically analyzed the ubiquity of the dis-tribution of identified Fusarium and non-Fusarium derived fungal toxin biosynthesis gene clusters (BGCs) in these species through the mining of core genes and comparative analysis of correspond-ing BGCs. Additionally, novel sesterterpene synthases and PKS_NRPS clusters were discovered and analysed. This work is the first to systematically analyze the distribution of related mycotoxin biosynthesis in pathogenic Fusarium species. These findings enhance the knowledge of mycotoxin production and provide a theoretical grounding for the prevention of fungal toxin production us-ing biotechnological approaches.

Pappia fissilis is a white-rot fungus capable of colonizing lignocellulosic substrates and decomposing plant cell wall components, and is likely involved in the degradation of woody debris and carbon cycling in forest ecosystems. A variety of lanostane-type triterpenoids and other bioactive compounds have been isolated from its fruiting bodies, pointing to potential value in natural product development. However, previous studies on this species have been largely confined to taxonomy, mitochondrial genomics, and chemical profiling of fruiting bodies, leaving its genomic features and the genetic underpinnings of wood decay and secondary metabolism poorly characterized. Here, we leveraged a hybrid sequencing strategy combining PacBio HiFi, Illumina, and Hi-C data to generate a chromosome-level genome assembly and annotation for P. fissilis, and conducted comprehensive phylogenomic, comparative genomic, CYP450, CAZyme, and biosynthetic gene cluster (BGC) analyses, which report the first genome resource for this species. The assembled genome spans 38.63 Mb, with 97.52% of the sequence anchored to 11 chromosomes, a BUSCO completeness of 95.4%, and 9499 predicted protein-coding genes. Phylogenomic analysis recovered P. fissilis as sister to a clade comprising Phlebia radiata and P. brevispora, with an estimated divergence time of approximately 53.17 Mya. The genome contains 153 CYP450 genes, 436 CAZyme genes, and 26 candidate BGCs harboring a total of 30 core biosynthetic genes (22 terpene, 5 T1PKS, 1 T3PKS, 2 $\beta$-lactone); these core genes are predominantly associated with terpene biosynthesis, and also encompass diverse types of polyketide synthase (PKS) genes as well as genes implicated in $\beta$-lactone biosynthesis. Collectively, these results establish a chromosome-level reference for investigating the genome evolution, wood-decay ecology, and secondary metabolic potential of P. fissilis, and lay the groundwork for future functional characterization of candidate biosynthetic genes and their associated natural products.

Plant pathogens pose a severe threat to global agricultural production, and their pathogenicity is closely linked to the biosynthesis of secondary metabolites. Basidiomycete within the family Ustilaginaceae represent significant plant pathogens, among which Ustilago maydis, as a model species, has been extensively studied for its secondary metabolites. However, the biosynthetic potential of other species within this family remains poorly understood. In this study, we conducted whole-genome bioinformatic analyses of 16 Ustilaginaceae species, including U. maydis, to systematically identify the distribution of biosynthetic gene clusters (BGCs), core gene domain compositions, and interspecies similarities. A total of 181 predicted BGCs were identified, averaging approximately 11 per species. BGCs for mannosylerythritol lipids (MELs), siderophores, and itaconic acid, as well as the melanin-associated genes pks1 and pks2, were widely distributed across most species. Conversely, an additional melanin biosynthetic gene cluster was found exclusively in U. maydis strain 521, indicating species-specific occurrence. Furthermore, this study identified a novel class of polyketide synthase (PKS) gene clusters with uncharacterized functions across 15 species, exhibiting high sequence and structural conservation between species. These findings reveal the rich metabolic diversity and species-specific biosynthetic potential of Ustilaginaceae, and by using U. maydis as a reference model, we highlight several BGCs (e.g., for MELs, siderophores, itaconic acid, and melanin) that are known to contribute to virulence or pathogenicity in plant hosts. This provides new insights into their pathogenic mechanisms.