Insect fungal pathogens secrete a cell wall-associated glucanase that acts to help avoid recognition by the host immune system.

Fungal insect pathogens have evolved diverse mechanisms to evade host immune recognition and defense responses. However, identification of fungal factors involved in host immune evasion during cuticular penetration and subsequent hemocoel colonization remains limited. Here, we report that the entomopathogenic fungus Beauveria bassiana expresses an endo-ß-1,3-glucanase (BbEng1) that functions in helping cells evade insect immune recognition/ responses. BbEng1 was specifically expressed during infection, in response to host cuticle and hemolymph, and in the presence of osmotic or oxidative stress. BbEng1 was localized to the fungal cell surface/ cell wall, where it acts to remodel the cell wall pathogen associated molecular patterns (PAMPs) that can trigger host defenses, thus facilitating fungal cell evasion of host immune defenses. BbEng1 was secreted where it could bind to fungal cells. Cell wall ß-1,3-glucan levels were unchanged in ΔBbEng1 cells derived from in vitro growth media, but was elevated in hyphal bodies, whereas glucan levels were reduced in most cell types derived from the BbEng1 overexpressing strain (BbEng1OE). The BbEng1OE strain proliferated more rapidly in the host hemocoel and displayed higher virulence as compared to the wild type parent. Overexpression of their respective Eng1 homologs or of BbEng1 in the insect fungal pathogens, Metarhizium robertsii and M. acridum also resulted in increased virulence. Our data support a mechanism by which BbEng1 helps the fungal pathogen to evade host immune surveillance by decreasing cell wall glucan PAMPs, promoting successful fungal mycosis.

A network of transcription factors in complex with a regulating cell cycle cyclin orchestrates fungal oxidative stress responses.

BACKGROUND: Response to oxidative stress is universal in almost all organisms and the mitochondrial membrane protein, BbOhmm, negatively affects oxidative stress responses and virulence in the insect fungal pathogen, Beauveria bassiana. Nothing further, however, is known concerning how BbOhmm and this phenomenon is regulated. RESULTS: Three oxidative stress response regulating Zn2Cys6 transcription factors (BbOsrR1, 2, and 3) were identified and verified via chromatin immunoprecipitation (ChIP)-qPCR analysis as binding to the BbOhmm promoter region, with BbOsrR2 showing the strongest binding. Targeted gene knockout of BbOsrR1 or BbOsrR3 led to decreased BbOhmm expression and consequently increased tolerances to free radical generating compounds (H2O2 and menadione), whereas the ΔBbOsrR2 strain showed increased BbOhmm expression with concomitant decreased tolerances to these compounds. RNA and ChIP sequencing analysis revealed that BbOsrR1 directly regulated a wide range of antioxidation and transcription-associated genes, negatively affecting the expression of the BbClp1 cyclin and BbOsrR2. BbClp1 was shown to localize to the cell nucleus and negatively mediate oxidative stress responses. BbOsrR2 and BbOsrR3 were shown to feed into the Fus3-MAPK pathway in addition to regulating antioxidation and detoxification genes. Binding motifs for the three transcription factors were found to partially overlap in the promoter region of BbOhmm and other target genes. Whereas BbOsrR1 appeared to function independently, co-immunoprecipitation revealed complex formation between BbClp1, BbOsrR2, and BbOsrR3, with BbClp1 partially regulating BbOsrR2 phosphorylation. CONCLUSIONS: These findings reveal a regulatory network mediated by BbOsrR1 and the formation of a BbClp1-BbOsrR2-BbOsrR3 complex that orchestrates fungal oxidative stress responses.

Phenotypic characteristics and immune response of Procypris merus following challenge with aquatic isolate of Klebsiella pneumoniae.

Currently, aquaculture is a relatively mature industry; however, disease problems are continuously threatening the industry and hindering its development to a certain extent. Klebsiella pneumoniae is one of the zoonotic bacteria widely present in different hosts and has caused some degree of harm to the aquaculture industry, posing a potential threat to the water environment and indirectly also affecting human food safety issues. In this study, K. pneumoniae was isolated from the aquaculture environment, named as ELD, and subjected to pathogenic and immunological related studies. The results of the study showed that the strain carries at least four virulence-related genes, magA, wabG, ureA and uge, and has developed resistance to at least seven antibacterial drugs, such as amoxicillin, doxycycline, rifampicin, and so on. Moreover, the strain is highly pathogenic and is capable of causing systemic clinical foci in Procypris merus. In addition, after infection with K. pneumoniae, the expression of IL-1ß, IL-8, HSP70 and C2 was upregulated in P. merus as a whole, whereas the expression of TNF-α did not change significantly in any of the tissues, which might be a kind of immune response of P. merus against K. pneumoniae infection. This study provides an important theoretical basis for the in-depth exploration of the pathogenic mechanism of K. pneumoniae in fish and the immune response that occurs after the disease is contracted in fish, as well as theoretical support for the development of effective preventive and therapeutic strategies against K. pneumoniae-infected aquatic animals in the future.

A case report and literature review on nephrogenic alveolar soft part sarcoma: clinicopathological manifestations and genetic features.

BACKGROUND: Alveolar soft part sarcoma (ASPS) is a rare kind of malignant soft tissue tumor with undefined differentiation, of which the incidence rate accounts for only 0.5-1.0% among all kinds of soft tissue tumors. An even rarer ASPS occurs in kidney. CASE PRESENTATION: Here we reported a case of a 7-year-old girl diagnosed with nephrogenic ASPS, regarding the analyses of the incidence, clinical manifestation, pathology and genetic diagnosis, in order to deepen the recognition of the disease. CONCLUSIONS: ASPS is very rare, and tends to occur to young patients. It is very significant to precisely diagnose ASPS at an early stage, which will be the key point for the following treatment choices and prognosis.

Mutation of a prenyltransferase results in accumulation of subglutinols and destruxins and enhanced virulence in the insect pathogen, Metarhizium anisopliae.

The insect pathogenic fungus, Metarhizium anisopliae is a commercialized microbial agent used in biological control efforts targeting a diverse range of agricultural and other insect pests. The second step in the synthesis of a group of M. anisopliae α-pyrone diterpenoids (termed subglutinols) involves the activity of a prenyltransferase family geranylgeranyl diphosphate synthase (product of the subD/MaGGPPS5 gene). Here, we show that targeted gene disruption of MaGGPPS5 results in earlier conidial germination and faster greater vegetative growth compared to the wild type (WT) parent and complemented strains. In addition, insect bioassays revealed that the ΔMaGGPPS5 mutant strain displayed significantly increased virulence, with a ~50% decrease in the mean lethal time (LT50 , from 6 to 3 days) to kill (50% of) target insects, and an ~15-40-fold decrease in the mean lethal dose (LC50 ). Metabolite profiling indicated increased accumulation in the ΔMaGGPPS5 mutant of select subglutinols (A, B and C) and destruxins (A, A2, B and B2), the latter a set of fungal secondary metabolites that act as insect toxins, with a concomitant loss of production of subglutinol 'analogue 45'. These data suggest that the increased virulence phenotype seen for the ΔMaGGPPS5 strain can, at least in part, be attributed to a combination of faster growth and increased insect toxin production, linking the production of two different secondary metabolite pathways, and represent a novel approach for the screening of isolates with enhanced virulence via modulation of terpenoid secondary metabolite biosynthesis.

Research on the indirect antiviral function of medicinal plant ingredient quercetin against grouper iridovirus infection.

Grouper iridovirus is a devastating pathogen that belongs to the genus Ranavirus. Based on the previous results that natural ingredient quercetin isolated from Illicium verum Hook. f. could effectively inhibit Singapore grouper iridovirus (SGIV) replication, suggesting that quercetin could serve as potential antiviral agent against grouper iridovirus. To know about whether quercetin has indirect antiviral activity against SGIV, this study made the investigation in vitro and in vivo, and the potential mechanism was also explored. Pretreating the cells with quercetin (12.5 µg/mL) significantly inhibited the replication of SGIV, similar results were also confirmed in vivo. Importantly, quercetin pretreatment could induce the expression of genes involved in type I interferon (IFN) system (IFN, STAT1, PKR, MxI and ISG15) and TLR9. It suggested that quercetin exerted the indirect antiviral activity against SGIV infection through promoting the recognition of SGIV and activating the IFN pathway to establish the antiviral status of host cell. Taken together, our results shedded light on the indirect antiviral function of natural ingredient quercetin, and clearly demonstrated that natural ingredient quercetin will be an excellent potential agent against SGIV infection in grouper aquaculture.

A novel transcription factor negatively regulates antioxidant response, cell wall integrity and virulence in the fungal insect pathogen, Beauveria bassiana.

Genomic data have identified a class of fungal specific transcription factors (FsTFs) that are thought to regulate unique aspects of fungal gene expression, although the functions of many of these proteins remain unknown. Here, a novel FsTF (BbStf1), which features a leucine zipper dimerization domain and a fungal transcription factor regulatory middle homology region, was characterized in Beauveria bassiana, a filamentous insect fungal pathogen. Transcriptional activation and nuclear localization were experimentally confirmed for BbStf1. Disruption of Bbstf1 resulted in increased tolerance to oxidative stress and cell wall perturbation, accompanied by increased peroxidase (POD) and superoxide dismutase (SOD) activities and ratio of reduced/oxidized glutathione (GSH/GSSG), and by thickened cell wall and altered composition. Gene expression profile analysis revealed that transcription patterns of antioxidant enzyme and cell wall integrity-involved genes were altered in the ∆Bbstf1, including some BbStf1-targeted genes clarified with evidence. The ∆Bbstf1 strain displayed greater virulence to Galleria mellonella in the bioassays through both topical infection and intrahaemocoel injection due to more rapid proliferation in the haemocoel as compared to the wild-type strain. Altogether, BbStf1 acts as a negative regulator of antioxidant response, cell wall integrity and virulence in B. bassiana.

The Thm1 Zn(II)2 Cys6 transcription factor contributes to heat, membrane integrity and virulence in the insect pathogenic fungus Beauveria bassiana.

The ability to withstand heat and cell wall stress is critical for successful infection of target hosts by many pathogenic fungi. We report on the characterization of BbThm1 (transcription factor for heat and membrane integrity), a Zn(II)2 Cys6 (Gal4-like) family member, which regulates resistance to heat (32°C) and specific detergents in the insect pathogenic fungus, Beauveria bassiana. BbThm1 gene knock-out mutants showed severely impaired growth/resistance at 32°C and to SDS, but mild to moderate phenotypic responses to other stresses including oxidative, osmotic and cell-wall targeting compounds, or to various fungicides. Shifts in cell wall properties, adhesion and decreased viability were noted for the ΔBbThm1 mutant. Susceptibility to SDS but not heat could be rescued by exogenous ergosterol. Insect bioassays revealed decreased virulence of the ΔBbThm1 mutant against Galleria mellonella both topically and via intrahemocoel injection assays that correlated with impaired in insecta hyphal body formation and altered host immune prophenol oxidase (PO) activation. Transcriptomic analyses of the wild-type and ΔBbThm1 mutants revealed up-regulation of hydrolases but down-regulation of a wide range of basic metabolic processes. These data reveal fine tune aspects of the transcription factor network that regulates specific stress responses to contribute to the overall pathogenic process.

Transparent Omniphobic Coating with Glass-Like Wear Resistance and Polymer-Like Bendability.

Transparent omniphobic or anti-smudge coatings with glass-like wear resistance and polymer-like bendability have many potential applications but there are no reports of such materials. We Report herein a molecular composite possessing these properties. The composite is prepared via the photo-initiated ring-opening polymerization of the epoxide rings of glycidyloxypropyl polyhedral silsesquioxane (GPOSS). While the desired hardness is provided by the silica core, the flexibility is imparted by the glycidyloxypropyl network. Oil and water repellency is achieved without adversely affecting the other properties by incorporating a low-surface-tension liquid lubricant poly(dimethyl siloxane). On the final coating, various organic solvents and water readily and cleanly glide, while complex fluids, such as ink and paint facilely contract. These properties are retained after an initially flat coating sample is rolled into a U-shape 500 times or is abraded with steel wool.

Microbiota in insect fungal pathology.

Significant progress has been made in the biochemical and genetic characterization of the host-pathogen interaction mediated by insect pathogenic fungi, with the most widely studied being the Ascomycetes (Hypocrealean) fungi, Metarhizium robertsii and Beauveria bassiana. However, few studies have examined the consequences and effects of host (insect) microbes, whether compatible or antagonistic, on the development and survival of entomopathogenic fungi. Host microbes can act on the insect cuticular surface, within the gut, in specialized insect microbe hosting structures, and within cells, and they include a wide array of facultative and/or obligate exosymbionts and endosymbionts. The insect microbiome differs across developmental stages and in response to nutrition (e.g., different plant hosts for herbivores) and environmental conditions, including exposure to chemical insecticides. Here, we review recent advances indicating that insect-pathogenic fungi have evolved a spectrum of strategies for exploiting or suppressing host microbes, including the production of antimicrobial compounds that are expressed at discrete stages of the infection process. Conversely, there is increasing evidence that some insects have acquired microbes that may be specialized in the production of antifungal compounds to combat infection by (entomopathogenic) fungi. Consideration of the insect microbiome in fungal insect pathology represents a new frontier that can help explain previously obscure ecological and pathological aspects of the biology of entomopathogenic fungi. Such information may lead to novel approaches to improving the efficacy of these organisms in pest control efforts.

In Situ Generated Janus Fabrics for the Rapid and Efficient Separation of Oil from Oil-in-Water Emulsions.

A cotton fabric was coated with a polymer that contains both poly(dimethyl siloxane) (PDMS) and poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA). When the repeat unit number of PDMS is about three-fold that of PDMAEMA and the fabric is exposed to air, the fabric is superhydrophobic because PDMS in the coating covers the PDMAEMA chains. Upon contact with an oil-in-water emulsion, the water-soluble PDMAEMA rises to the top and the side in contact with the emulsion becomes hydrophilic. The emerged PDMAEMA chains then cause the emulsion droplets to coagulate, and the aggregated oil fills the pores on the superhydrophobic side of the fabric. The oil-impregnated side remains hydrophobic even upon prolonged contact with water. Thus, a Janus fabric is elegantly generated in situ and sustained. This easy-to-prepare Janus fabric rapidly and efficiently separates oil from emulsions and may find practical applications.

A novel mitochondrial membrane protein, Ohmm, limits fungal oxidative stress resistance and virulence in the insect fungal pathogen Beauveria bassiana.

The Hog1 mitogen-activated protein (MAP) kinase regulates environmental stress responses and virulence in the entomopathogenic fungus Beauveria bassiana. To further characterize this pathway, we constructed a subtraction library enriched for genes regulated by Hog1. One targeted gene, encoding a novel membrane protein, Ohmm (oxidative homeostasis membrane-protein-mitochondria), was uniquely identified as being downregulated in the ΔHog1 background during growth under non-stress and osmotic stress conditions, but upregulated under oxidative stress. Ohmm was an experimentally validated flavin-binding protein and targeted to the mitochondria. Deletion of Ohmm resulted in increased oxidative stress resistance, whereas overexpression caused an opposite phenotype. The ΔOhmm showed accumulation of reactive oxygen species with alterations in cell wall composition and compatible solute accumulation evident as compared with the wild type parent. Conidiation was reduced > 80%; however, conidia produced by the ΔOhmm strain germinated significantly faster than wild type cells. Insect bioassays using the greater wax moth revealed increased virulence for the ΔOhmm strain in both topical and intrahemocoel injection assays, indicating a negative effect of the presence of Ohmm with respect to pathogenesis. As predicted from our characterization, deletion of Ohmm in a ΔHog1 background rescued its oxidative sensitivity phenotype, confirming that Ohmm acts downstream of the Hog1 MAP-kinase.

Interplay between calcineurin and the Slt2 MAP-kinase in mediating cell wall integrity, conidiation and virulence in the insect fungal pathogen Beauveria bassiana.

The entomopathogenic fungus, Beauveria bassiana, is of environmental and economic importance as an insect pathogen, currently used for the biological control of a number of pests. Cell wall integrity and conidiation are critical parameters for the ability of the fungus to infect insects and for production of the infectious propagules. The contribution of calcineurin and the Slt2 MAP kinase to cell wall integrity and development in B. bassiana was investigated. Gene knockouts of either the calcineurin CNA1 subunit or the Slt2 MAP kinase resulted in decreased tolerance to calcofluor white and high temperature. In contrast, the Δcna1 strain was more tolerant to Congo red but more sensitive to osmotic stress (NaCl, sorbitol) than the wild type, whereas the Δslt2 strain had the opposite phenotype. Changes in cell wall structure and composition were seen in the Δslt2 and Δcna1 strains during growth under cell wall stress as compared to the wild type. Both Δslt2 and Δcna1 strains showed significant alterations in growth, conidiation, and viability. Elevation of intracellular ROS levels, and decreased conidial hydrophobicity and adhesion to hydrophobic surfaces, were also seen for both mutants, as well as decreased virulence. Under cell wall stress conditions, inactivation of Slt2 significantly repressed CN-mediated phosphatase activity suggesting some level of cross talk between the two pathways. Comparative transcriptome profiling of the Δslt2 and Δcna1 strains revealed alterations in the expression of distinct gene sets, with overlap in transcripts involved in cell wall integrity, stress response, conidiation and virulence. These data illustrate convergent and divergent phenotypes and targets of the calcineurin and Slt2 pathways in B. bassiana.

Different mechanism of LPS-induced calcium increase in human lung epithelial cell and microvascular endothelial cell: a cell culture study in a model for ARDS.

Acute respiratory distress syndrome (ARDS) is a contemporary term incorporating the historic 'acute lung injury' and the colloquial term 'shock lung'. ARDS remains a serious and enigmatic human disease, causing significant mortality. The mechanisms involved at the alveolar cell/capillary endothelial interface have been explored but to date we lack clarity on the role of intracellular calcium ([Ca(2+)]i) fluxes across this interface. To explore the mechanisms of Ca(2+) induced inflammatory reaction in epithelial cells and pulmonary microvascular endothelial cells (HMVEC) located at the two sides of blood-air barrier, lung epithelial A549 and HMVEC cells were treated with LPS. Our results demonstrated that LPS evoked the increase of [Ca(2+)]i, TNF-α and IL-8 in both cells types. The [Ca(2+)]i increases involved intracellular but not extracellular Ca(2+) sources in A549, but both intracellular and extracellular Ca(2+) sources in HMVEC cells. The effects of LPS on both cells types were completely inhibited by the combination of LPS and CaSR-targeted siRNA. Furthermore, LPS-inhibited cell proliferations were significantly reversed by the combined treatment. Therefore, LPS induced different mechanisms of [Ca(2+)]i increase during the activation of CaSR in A549 and HMVEC cells, which translates into functional outputs related to ARDS.

Helix-Sense-Selective Permeation of Racemic Helical Oligoacetylenes through One-Handed Helical Channels in Polymer Membranes.

Helix-sense-selective permeation (HSSPerm) of racemic helical oligoacetylenes through one-handed helical channels has been realized. The one-handed helical channels were created in the one-handed helical polyacetylene membranes by the helix-sense-selective decomposition (HSS-SCAT) of the corresponding racemic helical polyacetylene membranes, followed by removing the formed oligomers. Since the HSS-SCAT reaction proceeds with just circularly polarized visible light with no reagents, no catalysts, no solvent, and high selectivity, the chiral channel-containing membrane with high purity was obtained easily. This membrane could separate racemic helical oligoacetylenes enantioselectively in up to 30%ee. To our knowledge, this is the first example of HSSPerm.

SHC1 serves as a prognostic and immunological biomarker in clear cell renal cell carcinoma: a comprehensive bioinformatics and experimental analysis.

SHC1 plays a crucial regulatory role in various tumors, but its significance in predicting prognosis and immune response in clear cell renal cell carcinoma (ccRCC) is yet to be determined. In this study, we conducted a bioinformatics analysis of SHC1 expression, prognosis, and immunological functions in ccRCC using multiple databases. The association between SHC1 and immune infiltration, immune escape, and immunotherapy in ccRCC was systematically established. In addition, we validated our results by western blot of tumor and adjacent-tumor samples from nine ccRCC patients, as well as three renal carcinoma cell lines compared to a normal renal cell line. Our analysis revealed that the mRNA expression level of SHC1 in ccRCC tissues is significantly higher than that in normal tissues. Consistently, western blot experiment showed ccRCC tissues and cell lines exhibit higher protein levels that normal tissues and cell lines. Importantly, patients with low expression of SHC1 demonstrated a higher survival rate, indicating that SHC1 could serve as an independent prognostic factor for predicting survival in ccRCC. Additionally, high expression of SHC1 was associated with increased severe immune cell infiltration, enhanced immune escape, and higher immunotherapy scores. Hence, SHC1 emerges as a novel and easily detectable biomarker for predicting clinical outcomes, immune escape, and immunotherapy response in patients with ccRCC.

Nasal Administration of bFGF-Loaded Nanoliposomes Attenuates Neuronal Injury and Cognitive Deficits in Mice with Vascular Dementia Induced by Repeated Cerebral Ischemia‒Reperfusion.

Introduction: Basic fibroblast growth factor (bFGF) shows great potential for preventing vascular dementia (VD). However, the blood‒brain barrier (BBB) and low bioavailability of bFGF in vivo limit its application. The present study investigated how nasal administration of bFGF-loaded nanoliposomes (bFGF-lips) affects the impaired learning and cognitive function of VD mice and the underlying mechanism involved. Methods: A mouse model of VD was established through repeated cerebral ischemia‒reperfusion. A Morris water maze (MWM) and novel object recognition (NOR) tests were performed to assess the learning and cognitive function of the mice. Hematoxylin and eosin (HE) staining, Nissl staining and TUNEL staining were used to evaluate histopathological changes in mice in each group. ELISA and Western blot analysis were used to investigate the molecular mechanism by which bFGF-lips improve VD incidence. Results: Behavioral and histopathological analyses showed that cognitive function was significantly improved in the bFGF-lips group compared to the VD and bFGF groups; in addition, abnormalities and the apoptosis indices of hippocampal neurons were significantly decreased. ELISA and Western blot analysis revealed that bFGF-lips nasal administration significantly increased the concentrations of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), bFGF, B-cell lymphoma 2 (Bcl-2), phosphorylated protein kinase B (PAKT), nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H quinone oxidoreductase 1 (NQO1) and haem oxygenase-1 (HO-1) in the hippocampus of bFGF-lips mice compared with the VD and bFGF groups. Furthermore, the concentrations of malondialdehyde (MDA), caspase-3 and B-cell lymphoma 2-associated X (Bax) were clearly lower in the bFGF-lips group than in the VD and bFGF groups. Conclusion: This study confirmed that the nasal administration of bFGF-lips significantly increased bFGF concentrations in the hippocampi of VD mice. bFGF-lips treatment reduced repeated I/R-induced neuronal apoptosis by regulating apoptosis-related protein concentrations and activating the phosphatidylinositol-3-kinase (PI3K)/(AKT)/Nrf2 signaling pathway to inhibit oxidative stress.

Unlocking the Siderophore Biosynthesis Pathway and Its Biological Functions in the Fungal Insect Pathogen Beauveria bassiana.

Siderophores are small molecule iron chelators. The entomopathogenic fungus Beauveria bassiana produces a plethora of siderophores under iron-limiting conditions. In this study, a siderophore biosynthesis pathway, akin to the general pathway observed in filamentous fungi, was revealed in B. bassiana. Among the siderophore biosynthesis genes (SID), BbSidA was required for the production of most siderophores, and the SidC and SidD biosynthesis gene clusters were indispensable for the production of ferricrocin and fusarinine C, respectively. Biosynthesis genes play various roles in siderophore production, vegetative growth, stress resistance, development, and virulence, in which BbSidA plays the most important role. Accordingly, B. bassiana employs a cocktail of siderophores for iron metabolism, which is essential for fungal physiology and host interactions. This study provides the initial network for the genetic modification of siderophore biosynthesis, which not only aims to improve the efficacy of biocontrol agents but also ensures the efficient production of siderophores.

A transcription factor-mediated regulatory network controls fungal pathogen colonization of insect body cavities.

Successful host tissue colonization is crucial for fungal pathogens to cause mycosis and complete the infection cycle, in which fungal cells undergo a series of morphological transition-included cellular events to combat with hosts. However, many transcription factors (TFs) and their mediated networks regulating fungal pathogen colonization of host tissue are not well characterized. Here, a TF (BbHCR1)-mediated regulatory network was identified in an insect pathogenic fungus, Beauveria bassiana, that controlled insect hemocoel colonization. BbHCR1 was highly expressed in fungal cells after reaching insect hemocoel and controlled the yeast (in vivo blastospores)-to-hyphal morphological switch, evasion of immune defense response, and fungal virulence. Comparative analysis of RNA sequencing and chromatin immunoprecipitation sequencing identified a core set of BbHCR1 target genes during hemocoel colonization, in which abaA and brlA were targeted to limit the rapid switch from blastospores to hyphae and fungal virulence. Two targets encoding hypothetical proteins, HP1 and HP2, were activated and repressed by BbHCR1, respectively, which acted as a virulence factor and repressor, respectively, suggesting that BbHCR1 activated virulence factors but repressed virulence repressors during the colonization of insect hemocoel. BbHCR1 tuned the expression of two dominant hemocoel colonization-involved metabolite biosynthetic gene clusters, which linked its regulatory role in evasion of immune response. Those functions of BbHCR1 were found to be collaboratively regulated by Fus3- and Hog1-MAP kinases via phosphorylation. These findings have drawn a regulatory network in which Fus3- and Hog1-MAP kinases phosphorylate BbHCR1, which in turn controls the colonization of insect body cavities by regulating fungal morphological transition and virulence-implicated genes.IMPORTANCEFungal pathogens adopt a series of tactics for successful colonization in host tissues, which include morphological transition and the generation of toxic and immunosuppressive molecules. However, many transcription factors (TFs) and their linked pathways that regulate tissue colonization are not well characterized. Here, we identified a TF (BbHCR1)-mediated regulatory network that controls the insect fungal pathogen, Beauveria bassiana, colonization of insect hemocoel. During these processes, BbHCR1 targeted the fungal central development pathway for the control of yeast (blastospores)-to-hyphae morphological transition, activated virulence factors, repressed virulence repressors, and tuned the expression of two dominant hemocoel colonization-involved immunosuppressive and immunostimulatory metabolite biosynthetic gene clusters. The BbHCR1 regulatory function was governed by Fus3- and Hog1-MAP kinases. These findings led to a new regulatory network composed of Fus3- and Hog1-MAP kinases and BbHCR1 that control insect body cavity colonization by regulating fungal morphological transition and virulence-implicated genes.

Diversity and New Species of Ascomycota from Bamboo in China.

Bamboo is an economically important crop that has gained prominence as an alternative to wood to reduce deforestation and ecosystem destruction. Diseases of bamboo that typically occur on leaves and stems can cause significant loss, reducing the quality and yield of the bamboo. However, there are few reports identifying the fungal species diversity and potential pathogens of bamboo. Here, we describe four new species of plant fungi from the leaves of bamboo within Fujian provinces, China. Fungi were isolated from diseased leaves collected within Fujian province and identified based on their morphological characteristics and multilocus phylogenies using nucleotide sequences derived from combined datasets of the intervening 5.8S nrRNA gene (ITS), the 28S large subunit of nuclear ribosomal RNA gene (LSU), the large subunit of RNA polymerase I (rpb1), the translation elongation factor 1-α gene (tef1-α), and the partial beta-tubulin gene (tub2). These analyses helped reveal and clarify taxonomic relationships in the family Magnaporthaceae. The new species of bambusicolous fungi identified include two species of Bifusisporella, described as B. fujianensis sp. nov. and B. bambooensis sp. nov., and two species of Apiospora, described as A. fujianensis sp. nov. and A. fuzhouensis sp. nov. This study further expands the characterization and distribution of fungi associated with bamboo.