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Ganoderma is a well-known medicinal macrofungal genus, of which several species have been thoroughly studied from the medicinal perspective, but most species are rarely involved in. In this study, we focus on the polysaccharides extracted from Ganoderma boninense and their antioxidant activity. Ganoderma boninense is a serious pathogen of oil palms that are cultivated commercially in Southeast Asia. Response surface methodology was conducted to optimize the liquid medium composition, and the mycelia biomass reached 7.063 g/L, that is, 1.4-fold compared with the seed medium. The crude and purified polysaccharides extracted from the fermentation broth showed well 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging abilities, and the scavenging abilities of purified polysaccharides reached 94.47 % and 99.88 %, respectively. Six fractions of polysaccharides were extracted and purified from fruiting bodies, mycelia and fermentation broth separately with the elution buffers of distilled water and 0.1 M NaCl solution. Generally, the polysaccharides from fruiting bodies showed stronger protective effect on H 2 O 2 -induced HepG2 cell oxidative damage than other fractions. A total of five to seven monosaccharides were identified in the six fractions of polysaccharides. The correlation analysis revealed that the content of fucose was significantly correlated with the antioxidant activity of polysaccharides, while xylose showed negative correlation results. In summary, the polysaccharides from G. boninense have a potential to be used as natural antioxidants., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In the present study, eleven novel complete mitogenomes of Boletus were assembled and compared. The eleven complete mitogenomes were all composed of circular DNA molecules, with sizes ranging from 32,883 bp to 48,298 bp. The mitochondrial gene arrangement of Boletus varied greatly from other Boletales mitogenomes, and gene position reversal were observed frequently in the evolution of Boletus. Across the 15 core protein-coding genes (PCGs) tested, atp9 had the least and rps3 had the largest genetic distances among the eleven Boletus species, indicating varied evolution rates of core PCGs. In addition, the Ka/Ks value for nad3 gene was >1, suggesting that this gene was subject to possible positive selection pressure. Comparative mitogenomic analysis indicated that the intronic region was significantly correlated with the size of mitogenomes in Boletales. Two large-scale intron loss events were detected in the evolution of Boletus. Phylogenetic analyses based on a combined mitochondrial gene dataset yielded a well-supported (BPP ≥ 0.99; BS =100) phylogenetic tree for 72 Agaricomycetes, and the Boletus species had a close relationship with Paxillus. This study served as the first report on complete mitogenomes in Boletus, which will further promote investigations of the genetics, evolution and phylogeny of the Boletus genus., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2021. Published by Elsevier B.V.)

Hygrophorus russula (Schaeff.) Kauffman is an edible ectomycorrhizal fungus that is widely distributed in the world. In this study, the mitogenome of H. russula was sequenced and assembled. The mitogenome of H. russula is composed of circular DNA molecules, with a total size of 55,769 bp. Further analysis indicated that the frequent use of A and T in codons contributes to the high AT content (80.87%) in the H. russula mitogenome. Comparative analysis indicated that the length and base composition of the core protein-encoding genes, and the number of tRNA genes in the H. russula mitogenome varied from that of other Agaricales mitogenomes. Gene arrangement analysis revealed a novel gene order in the H. russula mitogenome. In addition, the expansion of the mitogenome in Agaricales was found to be closely related to the increase in the number of introns. Phylogenetic analysis of the combined mitochondrial gene set showed strong support for tree topologies, and H. russula was determined to be relatively distant from other Agaricales species. This study is the first report on the mitogenome of a member of genus Hygrophorus as well as family Hygrophoraceae, which improves our understanding of mitochondrial differentiation and evolution in the important ectomycorrhizal fungi Hygrophorus species., (Copyright © 2018. Published by Elsevier B.V.)

Lactarius is one of the most prominent genera of mushroom-forming fungi in the world. In the present study, complete mitochondrial genomes (mitogenomes) from six Lactarius species were sequenced and assembled. The six mitogenomes were all composed of circular DNA molecules, with total lengths ranging from 38,445 bp to 60,843 bp. The GC contents, GC skews, and AT skews of the mitogenomes varied among the six species. Mitogenomic synteny analysis revealed the presence of gene rearrangements among the mitogenomes. Among the 15 core protein coding genes (PCGs) within the mitogenomes, nad4L exhibited the least genetic distance among species, indicating a high degree of conservation. In addition, the Ka/Ks values for all 15 core PCGs were <1, suggesting that they were subject to purifying selection. Comparative analyses indicated that the increase of intron numbers and sizes contributed to the expansion of mitogenomes in Lactarius. Phylogenetic analyses based on three combined gene datasets yielded identical and well-supported (BPP ≥ 0.83) topologies, dividing the six Lactarius species into two groups. This study provides the first report of mitogenomes from Lactarius and promotes further understanding of the genetics, evolution, and phylogenetic relationships of this important ectomycorrhizal fungal genus., (Copyright © 2018. Published by Elsevier B.V.)

Lyophyllum decastes and Lyophyllum shimeji are the two primary species within the L. decastes complex, and they differ considerably in their nutritional lifestyles and preferred growth environments. However, differences in their mitogenomes have not yet been investigated. In this study, the mitogenomes of the two species were sequenced by next-generation sequencing technology, successfully assembled, and compared. The two mitogenomes of L. decastes and L. shimeji comprised circular DNA molecules of sizes 50,643 bp and 73,678 bp, respectively. The lengths and base compositions of their core protein coding genes (PCGs) and tRNA genes varied considerably between the two mitogenomes. Further, gene collinearity analysis indicated a large-scale gene rearrangement between the two mitogenomes. Of the 15 core PCGs, the genetic distance of the atp9 gene was the smallest between the two species, indicating that this gene was highly conserved in the two Lyophyllum species. Phylogenetic analysis based on a combined mitochondrial gene dataset resulted in a well-supported topology, wherein the two Lyophyllum species were most closely related to Tricholoma matsutake. This study represents the first report of mitogenomes for the Lyophyllum genus. As such, the results will provide a basis for understanding the differentiation and evolution of mitogenomes in the Lyophyllum genus., (Copyright © 2018. Published by Elsevier B.V.)

In this study, the mitochondrial genomes of six Russula species were sequenced using next generation sequencing. The six mitogenomes were all composed of circular DNA molecules, with lengths ranging from 40,961 bp to 69,423 bp. The length and number of protein coding genes (PCGs), GC content, AT skew, and GC skew varied among the six mitogenomes. The increased number and total size of introns likely contributed to the size expansion of mitogenomes in some Russula species. Gene synteny analysis revealed some gene rearrangements among the six mitochondrial genomes. The nad4L gene had the lowest K2P genetic distance of the 15 core PCGs among the six Russula species, indicating that this gene was highly conserved. The Ka/Ks values for all 15 core PCGs were <1, suggesting that they were all subject to purifying selection. Phylogenetic analyses based on two gene datasets (15 core PCGs, and 15 core PCGs + rnl + rns) recovered identical and well-supported trees. In addition, cox1 was identified as a potential single-gene molecular marker for the phylogenetic analysis of relationships among Agaricomycetes species. This study provides the first report of mitogenomes from the Russulaceae family and facilitates the investigation of population genetics and evolution of other ectomycorrhizal fungi., (Copyright © 2018. Published by Elsevier B.V.)

Cantharellus is a large ectomycorrhizal genus. Here, we assembled and annotated the mitochondrial genomes of C. lutescens, C. appalachiensis, and two specimens of C. cibarius. We found that all four mitochondrial genomes were circular and between 56,786 bp and 80,736 bp, long. The length and GC content of the protein-coding genes (PCGs) in the four mitogenomes varied. All tRNAs were folded into classical cloverleaf secondary structures; 16 of the 26 identified tRNAs contained variable sites across Cantharellus genus. C. appalachiensis was found containing the most repeated sequences (11.32% of the mitogenome), along with a substantial number of gene rearrangements. Comparative analysis of three C. cibarius specimens indicated that the mitogenomes of specimens from different regions differed. The Ka/Ks ratios of all 15 PCGs identified across all four mitogenomes were <1, indicating that these genes have been subject to purifying selection. Phylogenetic analysis recovered a well-supported tree based on a combined analysis of the 15 PCGs. In addition, we identified cob, cox1, and rnl as potential single-gene markers for the analysis of phylogenetic relationships among Agaricomycetes species. The mitogenomes reported in this study will facilitate the study of population genetics and evolution in Cantharellus and other closely related species., (Copyright © 2018 Elsevier B.V. All rights reserved.)