HapX-mediated H2B deub1 and SreA-mediated H2A.Z deposition coordinate in fungal iron resistance.

Plant pathogens are challenged by host-derived iron starvation or excess during infection, but the mechanism through which pathogens counteract iron stress is unclear. Here, we found that Fusarium graminearum encounters iron excess during the colonization of wheat heads. Deletion of heme activator protein X (FgHapX), siderophore transcription factor A (FgSreA) or both attenuated virulence. Further, we found that FgHapX activates iron storage under iron excess by promoting histone H2B deubiquitination (H2B deub1) at the promoter of the responsible gene. Meanwhile, FgSreA is shown to inhibit genes mediating iron acquisition during iron excess by facilitating the deposition of histone variant H2A.Z and histone 3 lysine 27 trimethylation (H3K27 me3) at the first nucleosome after the transcription start site. In addition, the monothiol glutaredoxin FgGrx4 is responsible for iron sensing and control of the transcriptional activity of FgHapX and FgSreA via modulation of their enrichment at target genes and recruitment of epigenetic regulators, respectively. Taken together, our findings elucidated the molecular mechanisms for adaptation to iron excess mediated by FgHapX and FgSreA during infection in F. graminearum and provide novel insights into regulation of iron homeostasis at the chromatin level in eukaryotes.

Transcriptional insights of citrus defense response against Diaporthe citri.

Citrus melanose, caused by Diaporthe citri, is one of the most important and widespread fungal diseases of citrus. Previous studies demonstrated that the citrus host was able to trigger the defense response to restrict the spread of D. citri. However, the molecular mechanism underlying this defense response has yet to be elucidated. Here, we used RNA-Seq to explore the gene expression pattern at the early (3 days post infection, dpi) and late (14 dpi) infection stages of citrus leaves in response to D. citri infection, and outlined the differences in transcriptional regulation associated with defense responses. The functional enrichment analysis indicated that the plant cell wall biogenesis was significantly induced at the early infection stage, while the callose deposition response was more active at the late infection stage. CYP83B1 genes of the cytochrome P450 family were extensively induced in the callus deposition-mediated defense response. Remarkably, the gene encoding pectin methylesterase showed the highest upregulation and was only found to be differentially expressed at the late infection stage. Genes involved in the synthesis and regulation of phytoalexin coumarin were effectively activated. F6'H1 and S8H, encoding key enzymes in the biosynthesis of coumarins and their derivatives, were more strongly expressed at the late infection stage than at the early infection stage. Collectively, our study profiled the response pattern of citrus leaves against D. citri infection and provided the transcriptional evidence to support the defense mechanism.

The calcium-calcineurin and high-osmolarity glycerol pathways co-regulate tebuconazole sensitivity and pathogenicity in Fusarium graminearum.

The calcium-calcineurin and high-osmolarity glycerol (HOG) pathways play crucial roles in fungal development, pathogenicity, and in responses to various environmental stresses. However, interaction of these pathways in regulating fungicide sensitivity remains largely unknown in phytopathogenic fungi. In this study, we investigated the function of the calcium-calcineurin signalling pathway in Fusarium graminearum, the causal agent of Fusarium head blight. Inhibitors of Ca2+ and calcineurin enhanced antifungal activity of tebuconazole (an azole fungicide) against F. graminearum. Deletion of the putative downstream transcription factor FgCrz1 resulted in significantly increased sensitivity of F. graminearum to tebuconazole. FgCrz1-GFP was translocated to the nucleus upon tebuconazole treatment in a calcineurin-dependent manner. In addition, deletion of FgCrz1 increased the phosphorylation of FgHog1 in response to tebuconazole. Moreover, the calcium-calcineurin and HOG signalling pathways exhibited synergistic effect in regulating pathogenicity and sensitivity of F. graminearum to tebuconazole and multiple other stresses. RNA-seq data revealed that FgCrz1 regulated expression of a set of non-CYP51 genes that are associated with tebuconazole sensitivity, including multidrug transporters, membrane lipid biosynthesis and metabolism, and cell wall organization. Our findings demonstrate that the calcium-calcineurin and HOG pathways act coordinately to orchestrate tebuconazole sensitivity and pathogenicity in F. graminearum, which may provide novel insights in management of Fusarium disease.

Comparative physiological and transcriptome analysis provide insights into the inhibitory effect of 6-pentyl-2H-pyran-2-one on Clarireedia jacksonii.

Clarireedia spp. is a destructive phytopathogenic fungus that causes turf dollar spot of bent-grass, leading to widespread lawn death. In this study, we explored the antifungal capability of 6-pentyl-2H-pyran-2-one (6PP), a natural metabolite volatilized by microorganisms, which plays an important role in the biological control of turfgrass dollar spot. However, the mechanisms by which 6PP inhibits Clarireedia jacksonii remain unknown. In the present study, C. jacksonii mycelial growth was inhibited by the 6PP treatment and the 6PP treatment damaged cell membrane integrity, causing an increase in relative conduc-tivity. Furthermore, physiological and biochemistry assay showed that 6PP treatment can enhance reactive oxygen species (ROS) levels, malondialdehyde (MDA) content obviously increased with 6PP exposure, increased alchohol dehydrogenase (ADH) and depleted acetalde-hyde dehydrogenase (ALDH), and activated the activities of many antioxidant enzymes in C. jacksonii. Gen Ontology and Kyoto Encyclopedia of Genes and Genomes analysis revealed that some genes in C. jacksonii after 6PP treatment related to integrity of the cell wall and membrane, and oxidative stress were significantly downregulated. It is worth mentioning that the fatty acid degradation pathway is significantly upregulated, with an increase in ATP content and ATP synthase activity, which may promote fungal cell apoptosis. Moreover, we found that the expression of ABC transporters, and glutathione metabolism encoding genes were increased to respond to external stimuli. Taken together, these findings revealed the potential antifungal mechanism of 6PP against Clarireedia spp., which also provides a theoretical basis for the commercial utilization of 6PP as a green pesticide in the future.

Gene co-expression analysis reveals transcriptome divergence between wild and cultivated chickpea under drought stress.

Ancestral adaptations in crop wild relatives can provide a genetic reservoir for crop improvement. Here we document physiological changes to mild and severe drought stress, and the associated transcriptome dynamics in both wild and cultivated chickpea. Over 60% of transcriptional changes were related to metabolism, indicating that metabolic plasticity is a core and conserved drought response. In addition, changes in RNA processing and protein turnover were predominant in the data, suggestive of broad restructuring of the chickpea proteome in response to drought. While 12% of the drought-responsive transcripts have similar dynamics in cultivated and wild accessions, numerous transcripts had expression patterns unique to particular genotypes, or that distinguished wild from cultivated genotypes and whose divergence may be a consequence of domestication. These and other comparisons provide a transcriptional correlate of previously described species' genetic diversity, with wild accessions well differentiated from each other and from cultivars, and cultivars essentially indistinguishable at the broad transcriptome level. We identified metabolic pathways such as phenylpropanoid metabolism, and biological processes such as stomatal development, which are differentially regulated across genotypes with potential consequences on drought tolerance. These data indicate that wild Cicer reticulatum may provide both conserved and divergent mechanisms as a resource in breeding for drought tolerance in cultivated chickpea.

Chromosome-Scale Genome Sequence of Alternaria alternata Causing Alternaria Brown Spot of Citrus.

Alternaria brown spot (ABS), caused by Alternaria alternata, is an economically important fungal disease of citrus worldwide. The ABS pathogen A. alternata tangerine pathotype can produce a host-specific ACT toxin, which is regulated by ACT toxin gene cluster located in the conditionally dispensable chromosome (CDC). Previously, we have assembled a draft genome of A. alternata tangerine pathotype strain Z7, which comprises 165 contigs. In this study, we report a chromosome-level genome assembly of A. alternata Z7 through the combination of Oxford Nanopore sequencing and Illumina sequencing technologies. The assembly of A. alternata Z7 had a total size of 34.28 Mb, with a GC content of 51.01% and contig N50 of 3.08 Mb. The genome is encompassed 12,067 protein-coding genes, 34 ribosomal RNAs, and 107 transfer RNAs. Interestingly, A. alternata Z7 is composed of 10 essential chromosomes and 2 CDCs, which is consistent with the experimental evidences of pulsed-field gel electrophoresis. To our best knowledge, this is the first chromosome-level genome assembly of A. alternata. In addition, a database for citrus-related Alternaria genomes has been established to provide public resources for the sequences, annotation and comparative genomics data of Alternaria spp. The improved genome sequence and annotation at the chromosome level is a significant step toward a better understanding of the pathogenicity of A. alternata. The database will be updated regularly whenever the genomes of newly isolated Alternaria spp. are available. The citrus-related Alternaria genomes database is open accessible through the Citrus Fungal Disease Database.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

The critical role of MetR/MetB/MetC/MetX in cysteine and methionine metabolism, fungal development and virulence of Alternaria alternata.

Methionine is a unique sulfur-containing amino acid, which plays an important role in biological protein synthesis and various cellular processes. Here, we characterized the biological functions of AaMetB, AaMetC, and AaMetX in the tangerine pathotype of Alternaria alternata Morphological analysis showed that the mutants lacking AaMetB, AaMetC, or AaMetX resulted in less aerial hypha and fewer conidia in artificial media. Pathogenicity analysis showed that AaMetB, AaMetC, and AaMetX are required for full virulence. The defects in vegetative growth, conidiation and virulence of ΔMetB, ΔMetC, and ΔMetX can be restored by exogenous methionine and homocysteine, indicating that AaMetB, AaMetC, and AaMetX are required for methionine biosynthesis. However, exogenous cysteine only restored the growth and virulence defects of ΔMetR but not ΔMetB/C/X, suggesting that AaMetR is essential for cysteine biosynthesis. Oxidant sensitivity assay showed that only ΔMetR is sensitive to H2O2 and many ROS-generating compounds, indicating that AaMetR is essential for oxidative tolerance. Interestingly, fungicides indoor bioassays showed that only the ΔMetR mutants are susceptive to chlorothalonil, a fungicide that could bind to the cysteine of glyceraldehyde-3-phosphate dehydrogenase. Comparative transcriptome analysis showed that the inactivation of MetB, MetC, MetX, or MetR significantly affected the expression of methionine metabolism-related genes. Moreover, the inactivation of AaMetR significantly affected the expression of many genes related to glutathione metabolism, which is essential for ROS tolerance. Taken together, our study provides genetic evidence to define the critical roles of AaMetB, AaMetC, AaMetX, and AaMetR in cysteine and methionine metabolism, fungal development and virulence of Alternaria alternata IMPORTANCE The transcription factor METR regulating methionine metabolism is essential for reactive oxygen species (ROS) tolerance and virulence in many phytopathogenic fungi. However, the underlying regulatory mechanism of METR involved in this process is still unclear. In the present study, we generated AaMetB, AaMetC and AaMetX deletion mutants and compared these mutants with AaMetR disrupted mutants. Interestingly, we found that AaMetB, AaMetC and AaMetX are required for vegetative growth, conidiation, and pathogenicity in Alternaria alternata, but not for ROS tolerance and cysteine metabolism. Furthermore, we found that METR is involved in the biosynthesis of cysteine, which is an essential substrate for the biosynthesis of methionine and glutathione. This study emphasizes the critical roles of MetR, MetB, MetC, MetX in the regulation of cysteine and methionine metabolism, as well as the cross-link with glutathione-mediated ROS tolerance in phytopathogenic fungi, which provides a foundation for future investigations.

Effects of mancozeb on citrus rhizosphere bacterial community.

Multiple and consecutive application of fungicide might damage the rhizosphere bacterial community of citrus. In order to evaluated effect of mancozeb on the chemical properties of citrus-cultivated soil and the richness and diversity of rhizosphere bacterial community. The abundance response of rhizosphere bacterial groups without application or with application of 1.333 g mg-1 mancozeb for 2, 4, 6 and 8 times were investigated, and further studied the relationship between the rhizosphere bacterial community and chemical properties of citrus-cultivated soil. We found the rhizosphere bacterial composition and diversity were distinct between soil planted with citrus and without citrus, in addition, the abundance of rhizosphere-associated bacterial species in the soil planted with citrus increased significantly. Meanwhile, the chemical properties and the richness and diversity of rhizosphere bacterial community of the soil planted with citrus did not significantly change among different application frequence of mancozeb. Moreover, with the increased applying times of mancozeb, the relative abundance of Candidatus, Saccharibacteria, Parcubacteria, and Proteobacteria increased but the abundance of Nitrospirae decreased. In our one-year trial, there were less adverse effects of mancozeb on the citrus-cultivated rhizosphere by the repeated application of mancozeb. Therefore, mancozeb, as a fungicide, could be used multiple times to control citrus disease.

The Genome Sequence of the Citrus Melanose Pathogen Diaporthe citri and Two Citrus-Related Diaporthe Species.

Melanose disease is one the most widely distributed and economically important fungal diseases of citrus worldwide. The causative agent is the filamentous fungus Diaporthe citri (syn. Phomopsis citri). Here, we report the genome assemblies of three strains of D. citri, namely strains ZJUD2, ZJUD14, and Q7, which were generated using a combination of PacBio Sequel long-read and Illumina paired-end sequencing data. The assembled genomes of D. citri ranged from 52.06 to 63.61 Mb in genome size, containing 15,977 to 16,622 protein-coding genes. We also sequenced and annotated the genome sequences of two citrus-related Diaporthe species, D. citriasiana and D. citrichinensis. In addition, a database for citrus-related Diaporthe genomes was established to provide a public platform to access genome sequences, genome annotation and comparative genomics data of these Diaporthe species. The described genome sequences and the citrus-related Diaporthe genomes database provide a useful resource for the study of fungal biology, pathogen-host interaction, molecular diagnostic marker development, and population genomic analyses of Diaporthe species. The database will be updated regularly when the genomes of newly isolated Diaporthe species are sequenced. The citrus-related Diaporthe genomes database is freely available for nonprofit use at zjudata.com/blast/diaporthe.php.

Transcriptome analysis reveals the tolerant mechanisms to cobalt and copper in barley.

Cobalt (Co) and copper (Cu) co-exist commonly in the contaminated soils and at excessive levels, they are toxic to plants. However, their joint effect and possible interaction have not been fully addressed. In this work, a hydroponic experiment was performed to investigate the combined effects of Co and Cu on two barley genotypes at transcriptional level by RNA-seq analysis. The results identified 358 genes inclusively expressed in both genotypes under single and combined treatments of Co and Cu, with most of them being related to metal transport, stress response and transcription factor. The combined treatment induced more differently expressed genes (DEGs) than the single treatment, with Yan66, a metal tolerant genotype having more DEGs than Ea52, a sensitive genotype. The pathways associated with anthocyanin biosynthesis, MAPK signaling, glutathione biosynthesis, phenylalanine metabolism, photosynthesis, arginin biosynthesis, fatty acid elongation, and plant hormone signal transduction biosynthesis were induced and inhibited in Yan66 and Ea52, respectively. Furthermore, flavonoid biosynthesis was much more largely enhanced and accordingly more free flavonoid components (naringin, narirutin and neohesperidin) were accumulated in Yan66 than in Ea52. It may be suggested that high tolerance to both Co and Cu in Yan66 is attributed to its high gene regulatory ability.

Thioredoxin and Glutaredoxin Systems Required for Oxidative Stress Resistance, Fungicide Sensitivity, and Virulence of Alternaria alternata.

This study determined the function of thioredoxin and glutaredoxin systems in the phytopathogenic fungus Alternaria alternata via analyzing mutants obtained from the targeted deletion of genes encoding thioredoxin peroxidase (Tsa1), thioredoxin reductase (Trr1), and glutathione reductase (Glr1). Trr1 and Glr1, but not Tsa1, are required for growth and conidiation. The reduced growth and conidiation seen in the Trr1 or Glr1 deletion mutant can be restored by glutathione. Deletion mutants showing growth inhibition by oxidants are defective for H2O2 detoxification and induce smaller lesions on citrus leaves. Trr1 and Glr1, but not Tsa1, also contribute to NaCl resistance. Glr1 is required for sorbitol resistance and is responsible for resistance to mancozeb and boscalid but not chlorothalonil fungicides, a novel phenotype that has not been reported in fungi. Trr1 is required for resistance to boscalid and chlorothalonil fungicides but confers susceptibility to mancozeb. The Tsa1 deletion mutant displays wild-type sensitivity to the tested fungicides. The expression of Tsa1 and Trr1 is regulated by the oxidative stress responsive regulators Yap1, Hog1, and Skn7. The expression of Tsa1, but not Trr1, is also regulated indirectly by the NADPH oxidase. The results indicate that the capability to resist oxidative stress is required for virulence of A. alternataIMPORTANCE The thioredoxin and glutaredoxin systems are important thiol antioxidant systems in cells, and knowledge of these two systems in the plant-pathogenic fungus A. alternata is useful for finding new strategies to reduce the virulence of this pathogen. In this study, we demonstrated that thiol antioxidant system-related genes (Tsa1, Trr1, and Glr1) are required for H2O2 detoxification and virulence in A. alternata Moreover, deletion of Trr1 results in hypersensitivity to the fungicides chlorothalonil and boscalid, and Glr1 deletion mutants are highly sensitive to mancozeb, which is the fungicide mostly used in citrus fields. Therefore, our findings demonstrate that the ability to detoxify reactive oxygen species (ROS) plays a critical role in pathogenesis on citrus and provide novel insights into the physiological functions of thiol-containing systems in fungicide sensitivity for A. alternata.

Characterization of the complete mitochondrial genome of the Libelloides sibiricus (Neuroptera, Ascalaphidae).

Libelloides sibiricus (Eversmann, 1850) is widely distributed in China, Korea and eastern Russia. To date, few studies have been conducted on this species, with the exception of morphological taxonomy studies. In this study, we sequenced the complete mitochondrial genome (mitogenome) of Libelloides sibiricus, which is 15,811 bp in length, with an overall A + T content of 74.8%, encoding 2 ribosomal RNA genes, 22 transfer RNA genes, 13 protein-coding genes, and a control region. The gene arrangement and components of L. sibiricus are identical to those of most other Neuropteran species. TAA is utilized as the termination codon for most PCGs and TAG for nd1, however, nd6 and atp6 used the incomplete termination codon TA- and cox1, cox2, nd5, cytb had termination codons consisting of only T-. In addition, we selected all known 59 species of Neuroptera from NCBI, and used Sialis hamata, Sialis melania, Sialis longidens and Sialis jiyuni (Megaloptera: Sialidae) as the outgroup. Phylogenetic analysis suggested that the mitogenome of L. sibiricus was the most closely related to L. macaronius and all the owlflies formed the monophyletic group within the superfamily Myrmeleontoidea.

First complete mitochondrial genome of Pselliophora (Diptera, Tipulidae): genome description and phylogenetic implications.

Pselliophora is widely distributed in Eurasia and China. To explore the characteristics of the mitogenome of Pselliophora and reveal phylogenetic relationships, the mitogenome of Pselliophora bifascipennis Brunetti, 1911 was sequenced and annotated. This is the first complete mitochondrial genome in this genus. Its mitogenome is 15821 bp in length, containing 13 protein-coding genes, 22 tRNA and 2 rRNA genes. Nucleotide compositions of its whole mitogenome are 39.09% for A, 38.49% for T, 13.42% for C, and 9.01% for G. Consistent with previous observations of Tipulidae species, the mitogenome of Pselliophora bifascipennis is highly conserved in gene size, organization and codon usage, and secondary structures of tRNAs. Most tRNAs have the typical clover-leaf structure. The control region is 1006 bp long with an A + T content of 92.7%. Phylogenetic tree analysis using the sequences of the mitochondrial genomes of Pselliophora bifascipennis and other Tipulidae species showed that Pselliophora bifascipennis is closely related to Tanyptera hebeiensis. These two species are grouped on the same branch, which is in accordance with the traditional morphological classification. The results of this study lay a foundation for screening molecular markers of mitochondrion for molecular identification and genetic structure research in Tipulidae species.

Functional Plasticity, Redundancy, and Specificity of Lanosterol 14α-Demethylase in Regulating the Sensitivity to DMIs in Calonectria ilicicola.

Cytochrome P450 sterol 14α-demethylase (CYP51) is a key enzyme involved in the sterol biosynthesis pathway and serves as a target for sterol demethylation inhibitors (DMIs). In this study, the 3D structures of three CPY51 paralogues from Calonectria ilicicola (C. ilicicola) were first modeled by AlphaFold2, and molecular docking results showed that CiCYP51A, CiCYP51B, or CiCYP51C proteins individually possessed two active pockets that interacted with DMIs. Our results showed that the three paralogues play important roles in development, pathogenicity, and sensitivity to DMI fungicides. Specifically, CiCYP51A primarily contributed to cell wall integrity maintenance and tolerance to abiotic stresses, and CiCYP51B was implicated in sexual reproduction and virulence, while CiCYP51C exerted negative regulatory effects on sterol 14α-demethylase activity within the ergosterol biosynthetic pathway, revealing its genus-specific function in C. ilicicola. These findings provide valuable insights into developing rational strategies for controlling soybean red crown rot caused by C. ilicicola.

Transcriptome Analysis Reveals Potential Regulators of DMI Fungicide Resistance in the Citrus Postharvest Pathogen Penicillium digitatum.

Green mold, caused by Penicillium digitatum, is the major cause of citrus postharvest decay. Currently, the application of sterol demethylation inhibitor (DMI) fungicide is one of the main control measures to prevent green mold. However, the fungicide-resistance problem in the pathogen P. digitatum is growing. The regulatory mechanism of DMI fungicide resistance in P. digitatum is poorly understood. Here, we first performed transcriptomic analysis of the P. digitatum strain Pdw03 treated with imazalil (IMZ) for 2 and 12 h. A total of 1338 genes were up-regulated and 1635 were down-regulated under IMZ treatment for 2 h compared to control while 1700 were up-regulated and 1661 down-regulated under IMZ treatment for 12 h. The expression of about half of the genes in the ergosterol biosynthesis pathway was affected during IMZ stress. Further analysis identified that 84 of 320 transcription factors (TFs) were differentially expressed at both conditions, making them potential regulators in DMI resistance. To confirm their roles, three differentially expressed TFs were selected to generate disruption mutants using the CRISPR/Cas9 technology. The results showed that two of them had no response to IMZ stress while ∆PdflbC was more sensitive compared with the wild type. However, disruption of PdflbC did not affect the ergosterol content. The defect in IMZ sensitivity of ∆PdflbC was restored by genetic complementation of the mutant with a functional copy of PdflbC. Taken together, our results offer a rich source of information to identify novel regulators in DMI resistance.

Combined network analysis and interpretable machine learning reveals the environmental adaptations of more than 10,000 ruminant microbial genomes.

Background: The ruminant gastrointestinal contains numerous microbiomes that serve a crucial role in sustaining the host's productivity and health. In recent times, numerous studies have revealed that variations in influencing factors, including the environment, diet, and host, contribute to the shaping of gastrointestinal microbial adaptation to specific states. Therefore, understanding how host and environmental factors affect gastrointestinal microbes will help to improve the sustainability of ruminant production systems. Results: Based on a graphical analysis perspective, this study elucidates the microbial topology and robustness of the gastrointestinal of different ruminant species, showing that the microbial network is more resistant to random attacks. The risk of transmission of high-risk metagenome-assembled genome (MAG) was also demonstrated based on a large-scale survey of the distribution of antibiotic resistance genes (ARG) in the microbiota of most types of ecosystems. In addition, an interpretable machine learning framework was developed to study the complex, high-dimensional data of the gastrointestinal microbial genome. The evolution of gastrointestinal microbial adaptations to the environment in ruminants were analyzed and the adaptability changes of microorganisms to different altitudes were identified, including microbial transcriptional repair. Conclusion: Our findings indicate that the environment has an impact on the functional features of microbiomes in ruminant. The findings provide a new insight for the future development of microbial resources for the sustainable development in agriculture.

The Alternaria alternata StuA transcription factor interacting with the pH-responsive regulator PacC for the biosynthesis of host-selective toxin and virulence in citrus.

IMPORTANCE: In this study, we used Alternaria alternata as a biological model to report the role of StuA in phytopathogenic fungi. Our findings indicated that StuA is required for Alternaria citri toxin (ACT) biosynthesis and fungal virulence. In addition, StuA physically interacts with PacC. Disruption of stuA or pacC led to decreased expression of seven toxin biosynthetic genes (ACCT) and toxin production. PacC could recognize and bind to the promoter regions of ACTT6 and ACTTR. Our results revealed a previously unrecognized (StuA-PacC)→ACTTR module for the biosynthesis of ACT in A. alternata, which also provides a framework for the study of StuA in other fungi.

Metagenomic and network analysis revealed wide distribution of antibiotic resistance genes in monkey gut microbiota.

The emergence and spread of drug-resistant microorganisms that have acquired new resistance mechanisms, leading to antibiotic resistance, continue to threaten the health of humans and animals worldwide. Non-human primates (NHPs), as close living relatives of human beings in the world, have a high degree of genetic and physiological similarity to humans. However, despite its importance, we lack a comprehensive characterization or understanding of the similarities and differences of the antibiotic resistance genes of the gut microbiome carried by non-human primates and humans. In the present study, the diversity and abundance of antibiotic resistance genes carried by the gut microbiota of cynomolgus monkeys (Macaca fascicularis) were investigated by metagenomic analysis. In total, 60 resistance types conferring resistance to 11 categories of antibiotics were identified in the gut microbiome of cynomolgus monkeys. Interestingly, the composition and abundance of ARGs carried by the gut microbiota of cynomolgus monkeys can be significantly affected by dietary changes. Moreover, we found that all ARG types carried by humans are also present in cynomolgus monkeys. The tetracycline resistance gene tet(37) is evolutionarily conserved and highly homologous. Taken together, our study provides a comprehensive overview of the diversity and richness of ARGs in the gut microbiota of cynomolgus monkeys and underlines the potentially crucial role of diet in the gut health of monkeys and humans.

GPI-Anchored Protein Homolog IcFBR1 Functions Directly in Morphological Development of Isaria cicadae.

Isaria cicadae is a famous edible and medicinal fungus in China and Asia. The molecular basis of morphogenesis and synnemal formation needs to be understood in more detail because this is the main source of biomass production in I. cicadae. In the present study, a fruiting body formation-related gene with a glycosylphosphatidylinositol (GPI) anchoring protein (GPI-Ap) gene homolog IcFBR1 was identified by screening random insertion mutants. Targeted deletion of IcFBR1 resulted in abnormal formation of synnemata, impairing aerial hyphae growth and sporulation. The IcFBR1 mutants were defective in the utilization of carbon sources with reduced polysaccharide contents and the regulation of amylase and protease activities. Transcriptome analysis of ΔIcfbr1 showed that IcFBR1 deletion influenced 49 gene ontology terms, including 23 biological processes, 9 molecular functions, and 14 cellular components. IcFBR1 is therefore necessary for regulating synnemal development, secondary metabolism, and nutrient utilization in this important edible and medicinal fungus. This is the first report illustrating that the function of IcFBR1 is associated with the synnemata in I. cicadae.