Redundancy in microbiota-mediated suppression of the soybean cyst nematode.

BACKGROUND: Soybean cyst nematodes (SCN) as animal parasites of plants are not usually interested in killing the host but are rather focused on completing their life cycle to increase population, resulting in substantial yield losses. Remarkably, some agricultural soils after long-term crop monoculture show a significant decline in SCN densities and suppress disease in a sustainable and viable manner. However, relatively little is known about the microbes and mechanisms operating against SCN in such disease-suppressive soils. RESULTS: Greenhouse experiments showed that suppressive soils (S) collected from two provinces of China and transplantation soils (CS, created by mixing 10% S with 90% conducive soils) suppressed SCN. However, SCN suppressiveness was partially lost or completely abolished when S soils were treated with heat (80 °C) and formalin. Bacterial community analysis revealed that the specific suppression in S and CS was mainly associated with the bacterial phylum Bacteroidetes, specifically due to the enrichment of Chitinophaga spp. and Dyadobacter sp., in the cysts. SCN cysts colonized by Chitinophaga spp. showed dramatically reduced egg hatching, with unrecognizable internal body organization of juveniles inside the eggshell due to chitinase activity. Whereas, Dyadobacter sp. cells attached to the surface coat of J2s increased soybean resistance against SCN by triggering the expression of defence-associated genes. The disease-suppressive potential of these bacteria was validated by inoculating them into conducive soil. The Dyadobacter strain alone or in combination with Chitinophaga strains significantly decreased egg densities after one growing cycle of soybeans. In contrast, Chitinophaga strains alone required more than one growing cycle to significantly reduce SCN egg hatching and population density. CONCLUSION: This study revealed how soybean monoculture for decades induced microbiota homeostasis, leading to the formation of SCN-suppressive soil. The high relative abundance of antagonistic bacteria in the cyst suppressed the SCN population both directly and indirectly. Because uncontrolled proliferation will likely lead to quick demise due to host population collapse, obligate parasites like SCN may have evolved to modulate virulence/proliferation to balance these conflicting needs. Video Abstract.

Rogersonins C-F, 9H-Imidazo[2,1-i]purine-Incorporating Adenine-Polyketide Hybrids from an Ophiocordyceps-Associated Clonostachys rogersoniana.

Rogersonins C-F (1-4), four unprecedented adenine-polyketide hybrids featuring a rare 9H-imidazo[2,1-i]purine (1,N6-ethenoadenine) moiety, were isolated from an Ophiocordyceps-associated fungus, Clonostachys rogersoniana. Their structures were elucidated primarily by NMR experiments. The absolute configurations of 1-4 were assigned by a combination of the modified Mosher method, chemical degradation, electronic circular dichroism (ECD) calculations, and X-ray crystallography using Cu Kα radiation. Compound 3 downregulated the expression of PD-L1 protein in MDA-MB-231 and A549 cells, but did not show detectable effect on mRNA transcription of the PD-L1-encoding gene CD274.

Microbiome-mediated alleviation of tobacco replant problem via autotoxin degradation after long-term continuous cropping.

Continuous cropping often results in severe "replant problem," across various crops due to the autotoxins accumulation, soil acidification, pathogens proliferation, and microbial dysfunction. We unveiled a groundbreaking phenomenon that long-term continuous cropping (LTCC) can alleviate the tobacco replant problem. This mitigation occurs through the enrichment of autotoxin-degrading microbes, and the transformative impact is evident with even a modest application (10%) of LTCC soil to short-term continuous cropping (STCC) soil. Our investigation has pinpointed specific autotoxin-degrading bacteria, particularly the Pseudomonas and Burkholderia species, which exhibit the capacity to alleviate the tobacco replant problem in STCC soil. Their autotoxin-degrading mechanism using axenic culture and soil samples was also conducted via comprehensive analyses of microbiome and transcriptome approach. This research sheds light on the potential of LTCC as a strategic approach for sustainable agriculture, addressing replant problems and promoting the health of cropping systems. UV, ultraviolet; OD, optical density.

Wild plant species with broader precipitation niches exhibit stronger host selection in rhizosphere microbiome assembly.

Plants actively recruit microbes from the soil, forming species-specific root microbiomes. However, their relationship with plant adaptations to temperature and precipitation remains unclear. Here we examined the host-selected and conserved microbiomes of 13 native plant species in the Xilingol steppe, Inner Mongolia, a semi-arid region in China. By calculating the global precipitation and temperature niches of these plants, considering plant phylogenetic distances, and analyzing functional traits, we found that these factors significantly influenced the rhizosphere microbiome assembly. We further quantified the strength of host selection and observed that plants with wider precipitation niches exhibited greater host selection strength in their rhizosphere microbiome assembly and higher rhizosphere bacterial diversity. In general, the rhizosphere microbiome showed a stronger link to plant precipitation niches than temperature niches. Haliangium exhibited consistent responsiveness to host characteristics. Our findings offer novel insights into host selection effects and the ecological determinants of wild plant rhizosphere microbiome assembly, with implications for steering root microbiomes of wild plants and understanding plant-microbiome evolution.

A CAR-T response prediction model for r/r B-NHL patients based on a T cell subset nomogram.

BACKGROUND: Chimeric antigen receptor (CAR) T cells for refractory or relapsed (r/r) B cell no-Hodgkin lymphoma (NHL) patients have shown promising clinical effectiveness. However, the factors impacting the clinical response of CAR-T therapy have not been fully elucidated. We here investigate the independent influencing factors of the efficacy of CD19 CAR-T cell infusion in the treatment of r/r B-NHL and to establish an early prediction model. METHODS: A total of 43 r/r B-NHL patients were enrolled in this retrospective study. The patients' general data were recorded, and the primary endpoint is the patients' treatment response. The independent factors of complete remission (CR) and partial remission (PR) were investigated by univariate and binary logistic regression analysis, and the prediction model of the probability of CR was constructed according to the determined independent factors. Receiver operating characteristic (ROC) and calibration plot were used to assess the discrimination and calibration of the established model. Furthermore, we collected 15 participators to validate the model. RESULTS: Univariate analysis and binary logistic regression analysis of 43 patients showed that the ratio of central memory T cell (Tcm) and naïve T cell (Tn) in cytotoxic T cells (Tc) was an independent risk factor for response to CD19 CAR-T cell therapy in r/r B-NHL. On this basis, the area under the curve (AUC) of Tcm in the Tc and Tn in the Tc nomogram model was 0.914 (95%CI 0.832-0.996), the sensitivity was 83%, and the specificity was 74.2%, which had excellent predictive value. We did not found the difference of the progression-free survival (PFS). CONCLUSIONS: The ratio of Tcm and Tn in Tc was found to be able to predict the treatment response of CD19 CAR-T cells in r/r B-NHL. We have established a nomogram model for the assessment of the CD19 CAR-T therapy response presented high specificity and sensitivity.

The diagnostic/prognostic roles and biological function of the IFIT family members in acute myeloid leukemia.

BACKGROUND: The Interferon-induced protein with tetratricopeptide repeat (IFIT) family, IFIT1/2/3/5, play an important role in different tumors progression. However, the prognosis significance and biological role of IFIT family members in acute myeloid leukemia (AML) remains unclear. METHODS: We obtained the gene expression data and clinical information of 173 AML patients from The Cancer Genome Atlas (TCGA) database. Several databases were used in our study, including GEPIA, MethSurv, STRING, GSCA and GeneMANIA database. RESULTS: The mRNA expression of IFIT1/2/3/5 was elevated in AML patients and had a high ability to distinguish AML from controls based on the receiver operating characteristic (ROC) curve (AUC > 0.9). Kaplan-Meier survival analysis showed that higher levels of IFIT2/3/5 expression predict poor prognosis in AML patients. Besides, the DNA methylation analysis suggested that 7 CpG sites of IFIT2, 4 CpG sites of IFIT3 and 10 CpG sites of IFIT5 were significantly associated with the prognosis of AML patients. In addition, IFIT2/3/5 expression was significantly positively associated with the immune cell infiltration and immune checkpoint expression, such as CTLA4, PDCD1, LAG3, and TIGIT. Finally, drug sensitivity analysis revealed that AML patients with high expression of IFIT2/3/5 were resistant to multiple drugs, but sensitive to dasatinib. CONCLUSION: IFIT family genes might serve as biomarkers for diagnosis, prognosis and drug sensitivity in AML patients. The activation or blocking of IFIT-related signaling pathways may provide novel insights into immunotherapy for patients with AML.

A palisade-shaped membrane reservoir is required for rapid ring cell inflation in Drechslerella dactyloides.

Fusion of individual vesicles carrying membrane-building materials with the plasma membrane (PM) enables gradual cell expansion and shape change. Constricting ring (CR) cells of carnivorous fungi triple in size within 0.1-1 s to capture passing nematodes. Here, we investigated how a carnivorous fungus, Drechslerella dactyloides, executes rapid and irreversible PM expansion during CR inflation. During CR maturation, vesicles carrying membrane-building materials accumulate and fuse, forming a structure named the Palisade-shaped Membrane-building Structure (PMS) around the rumen side of ring cells. After CR inflation, the PMS disappears, with partially inflated cells displaying wavy PM and fully inflated cells exhibiting smooth PM, suggesting that the PMS serves as the reservoir for membrane-building materials to enable rapid and extensive PM expansion. The DdSnc1, a v-SNARE protein, accumulates at the inner side of ring cells and is necessary for PMS formation and CR inflation. This study elucidates the unique cellular mechanisms underpinning rapid CR inflation.

Inhibition and biocontrol potential of Ochrobactrum pseudogrignonense NC1 against four Phytophthora species.

Phytophthora species are highly destructive soilborne oomycetes pathogens that spread through infested soil and water. Ochrobactrum pseudogrignonense NC1 has been shown to inhibit plant parasitic nematodes via volatile organic compounds (VOCs). In this study, we investigated the inhibitory effect of O. pseudogrignonense NC1 against four Phytophthora species on agar plates and in vivo bioassay. We found that NC1 significantly inhibited the mycelial growth and zoospore production of all four species of Phytophthora in a dose-dependent manner. The half maximal inhibitory concentration (IC50) values for inhibition of mycelial growth (or zoospore production) were 26% (14.8%), 18.9% (14.2%), 20.3% (8.3%) and 46.9% (4%) for Phytophthora capsici Leonian, Phytophthora infestans, Phytophthora parasitica var. nicotiana and Phytophthora sojae, respectively. The biocontrol efficiency of NC1 was 46.3% in pepper seedlings against P. capsici, almost 100% in potato tubers against P. infestans, 60% in tomato leave against P. parasitica and 100% in soybean leave against P. sojae, respectively. Our findings suggest that O. pseudogrignonense NC1 has great potential as a biocontrol agent for managing Phytophthora diseases.

Multiple Roles of the Low-Affinity Calcium Uptake System in Drechslerella dactyloides, a Nematode-Trapping Fungus That Forms Constricting Rings.

(1) Background: the low-affinity calcium uptake system (LACS) has been shown to play a crucial role in the conidiation and formation of adhesive nets and knobs by nematode-trapping fungi (NTF), but its involvement in the formation of constricting rings (CRs), mechanical traps to capture free-living nematodes, remains unexplored. (2) Methods: we investigated the function of two LACS genes (DdaFIG_1 and DdaFIG_2) in Drechslerella dactyloides, an NTF that forms CRs. We generated single (DdaFIG_1Ri and DdaFIG_2Ri) and double (DdaFIG_1,2Ri) knockdown mutants via the use of RNA interference (RNAi). (3) Results: suppression of these genes significantly affected conidiation, trap formation, vegetative growth, and response to diverse abiotic stresses. The number of CRs formed by DdaFIG_1Ri, DdaFIG_2Ri, and DdaFIG_1,2Ri decreased to 58.5%, 59.1%, and 38.9% of the wild-type (WT) level, respectively. The ring cell inflation rate also decreased to 73.6%, 60.6%, and 48.8% of the WT level, respectively. (4) Conclusions: the LACS plays multiple critical roles in diverse NTF.

Identification and Characterization of Peptaibols as the Causing Agents of Pseudodiploöspora longispora Infecting the Edible Mushroom Morchella.

Pseudodiploöspora longispora (previously known as Diploöspora longispora) is a pathogenic fungus of Morchella mushrooms. The molecular mechanism underlying the infection of P. longispora in fruiting bodies remains unknown. In this study, three known peptaibols, alamethicin F-50, polysporin B, and septocylindrin B (1-3), and a new analogue, longisporin A (4), were detected and identified in the culture of P. longispora and the fruiting bodies of M. sextelata infected by P. longispora. The primary amino sequence of longisporin A is defined as Ac-Aib1-Pro2-Aib3-Ala4-Aib5-Aib6-Gln7-Aib8-Val9-Aib10-Glu11-Leu12-Aib13-Pro14-Val15-Aib16-Aib17-Gln18-Gln19-Phaol20. The peptaibols 1-4 greatly suppressed the mycelial growth of M. sextelata. In addition, treatment with alamethicin F-50 produced damage on the cell wall and membrane of M. sextelata. Compounds 1-4 also exhibited inhibitory activities against human pathogens including Aspergillus fumigatus, Candida albicans, methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus, and plant pathogen Verticillium dahlia. Herein, peptaibols are confirmed as virulence factors involved in the invasion of P. longispora on Morchella, providing insights into the interaction between pathogenic P. longispora and mushrooms.

Aureane-type sesquiterpene tetraketides as a novel class of immunomodulators with interleukin-17A inhibitory activity.

Interleukin (IL)-17A, a pro-inflammatory cytokine, is a fundamental function in the onset and advancement of multiple immune diseases. To uncover the primary compounds with IL-17A inhibitory activity, a large-scale screening of the library of traditional Chinese medicine constituents and microbial secondary metabolites was conducted using splenic cells from IL-17A-GFP reporter mice cultured under Th17-priming conditions. Our results indicated that some aureane-type sesquiterpene tetraketides isolated from a wetland mud-derived fungus, Myrothecium gramineum, showed remarkable IL-17A inhibitory activity. Nine new aureane-type sesquiterpene tetraketides, myrogramins A-I (1, 4-11), and two known ones (2 and 3) were isolated and identified from the strain. Compounds 1, 3, 4, 10, and 11 exhibited significant IL-17A inhibitory activity. Among them, compound 3, with a high fermentation yield dose-dependently inhibited the generation of IL-17A and suppressed glycolysis in splenic cells under Th17-priming conditions. Strikingly, compound 3 suppressed immunopathology in both IL-17A-mediated animal models of experimental autoimmune encephalomyelitis and pulmonary hypertension. Our results revealed that aureane-type sesquiterpene tetraketides are a novel class of immunomodulators with IL-17A inhibitory activity, and hold great promise applications in treating IL-17A-mediated immune diseases.

Identification of new bisabosqual-type meroterpenoids reveals non-enzymatic conversion of bisabosquals into seco-bisabosquals.

Bisabosqual-type meroterpenoids are fungi-derived polyketide-terpenoid hybrids bearing a 2,3,3a,3a1,9,9a-hexahydro-1H-benzofuro[4,3,2-cde]chromene skeleton (6/6/6/5 ring system) or its seco-C-ring structure, and exhibit diverse bioactivities. Their unique structural architecture and impressive biological activities have led to considerable interest in discovering new analogues. However, to date, only nine analogues have been identified. Herein, we reported the isolation and identification of six new bisabosqual-type meroterpenoids stachybisbins C-H (1-6), together with one known compound bisabosqual C (7), from Stachybotrys bisbyi PYH05-7. Intriguingly, we found that 7, which contains the intact tetracyclic skeleton, can be non-enzymatically converted into its seco derivative stachybisbin I (8), unveiling the biosynthetic relationship between bisabosquals and seco-bisabosquals. Moreover, based on CRISPR/Cas9-mediated gene disruption, we revealed that the three-gene cluster responsible for the formation of LL-Z1272ß is associated with the biosynthesis of bisabosqual-type meroterpenoids, and then proposed a plausible route to 1-8.

Niche and ecosystem preference of earliest diverging fungi in soils.

Within the supergroup Rotosphaeromycetes, or "Holomycota"/"Nucletmycea", there are several well-recognised unicellular clades in the earliest diverging fungi (EDF). However, we know little about their occurrence. Here, we investigated EDF in the rhizosphere and bulk soils from cropland, forest, orchard, and wetland ecosystems around the Beijing-Hebei area, China, to illustrate their niche and ecosystem preference. More than 500 new operational taxonomic units (OTUs) of EDF were detected based on the 18S rRNA genes. Microsporida and Aphelida constitute dominant groups, whereas Rozellosporida was quite rare. Although the EDF community was site-specific, the soil chemical characteristics, vegetation, and other eukaryotic microorganisms were the key factors driving the occurrence of EDF. Moreover, the stochastic process consisted the most of the EDF community assembly.

DUSP2 inhibits the progression of lupus nephritis in mice by regulating the STAT3 pathway.

One of the most severe side effects of systemic lupus erythematosus (SLE) is lupus nephritis (LN). To search for potential therapeutic targets in SLE is crucial for the progression of SLE. In this study, we selected C57BL/6J mice as controls and MRL/lpr mice as an LN model and obtained dual specificity phosphatase 2 (DUSP2)-overexpressed mice by injecting AAV-DUSP2 plasmid into the tail vein. Then, proteinuria, urea nitrogen, dsDNA and TNF-α, IL-6, and IL-1ß levels were measured in each group of mice. In addition, renal histopathological damage was assessed by hematoxylin-eosin. Finally, STAT3 phosphorylation levels were detected by Western blot assay. The results showed that DUSP2 could reduce proteinuria, urea nitrogen, dsDNA and TNF-α, IL-6, and IL-1ß levels and improve renal tissue injury in mice with LN. Mechanistically, DUSP2 inhibited STAT3 phosphorylation. These results demonstrated that DUSP2 played a role in ameliorating LN, which provided potential targets for LN research.

Marasmius androsaceus mitigates depression-exacerbated intestinal radiation injuries through reprogramming hippocampal miRNA expression.

INTRODUCTION: Cancer patients commonly experience high levels of psychological stress, which poses significant risks to their well-being. Radiotherapy is a primary treatment modality for cancer; however, it often leads to intestinal injuries in these patients. Nevertheless, the impact of mental stress on radiotherapy-intertwined complications remains unclear. METHODS: To induce intestinal injury, we employed total abdominal irradiation in our experimental model. We conducted high-throughput sequencing to analyze the expression profile of miRNAs in the hippocampus. RESULTS: We observed that mice with depression exhibited more severe intestinal injuries following total abdominal irradiation. Remarkably, oral administration of Marasmius androsaceus not only alleviated the depressive phenotype but also mitigated radiation-induced intestinal toxicity. Notably, this radioprotective effect was not observed in mice without depression. Depression disrupted the hippocampal miRNA expression profile in mice subjected to local irradiation of the abdomen, leading to the accumulation of miR-139-5p and miR-184-3p in the hippocampus, serum, and small intestine tissues. However, treatment with Marasmius androsaceus reprogrammed the miRNA expression signature in mice with depression. Furthermore, intravenous injection of antagomirs targeting miR-139-5p and miR-184-3p ameliorated depression, up-regulated Spn expression, reduced radiation enteritis, and improved the integrity of the small intestine in irradiated mice. CONCLUSION: Our findings demonstrate the efficacy of Marasmius androsaceus, a small mushroom, in alleviating depression-aggravated intestinal toxicity following radiotherapy by reprogramming hippocampal miRNA expression.

Tools and basic procedures of gene manipulation in nematode-trapping fungi.

Nematode-trapping fungi (NTF) are the majority of carnivorous microbes to capture nematodes through diverse and sophisticated trapping organs derived from hyphae. They can adopt carnivorous lifestyles in addition to saprophytism to obtain extra-nutrition from nematodes. As a special group of fungi, the NTF are not only excellent model organism for studying lifestyle transition of fungi but also natural resources of exploring biological control of nematodes. However, the carnivorous mechanism of NTF remains poorly understood. Nowadays, the omics studies of NTF have provided numerous genes and pathways that are associated with the phenotypes of carnivorous traits, which need molecular tools to verify. Here, we review the development and progress of gene manipulation tools in NTF, including methodology and strategy of transformation, random gene mutagenesis methods and target gene mutagenesis methods. The principle and practical approach for each method was summarized and discussed, and the basic operational flow for each tool was described. This paper offers a clear reference and instruction for researchers who work on NTF as well as other group of fungi.

DhFIG_2, a gene of nematode-trapping fungus Dactylellina haptotyla that encodes a component of the low-affinity calcium uptake system, is required for conidiation and knob-trap formation.

Calcium ion (Ca2+) is a universal second messenger involved in regulating diverse processes in animals, plants, and fungi. The low-affinity calcium uptake system (LACS) participates in acquiring Ca2+ from extracellular environments under high extracellular Ca2+ concentration. Unlike most fungi, which encode only one protein (FIG1) for LACS, nematode-trapping fungi (NTF) encode two related proteins. AoFIG_2, the NTF-specific LACS component encoded by adhesive network-trap forming Arthrobotrys oligospora, was shown to be required for conidiation and trap formation. We characterized the role of DhFIG_2, an AoFIG_2 ortholog encoded by knob-trap forming Dactylellina haptotyla, in growth and development to expand our understanding of the role of LACS in NTF. Because repeated attempts to disrupt DhFIG_2 failed, knocking down the expression of DhFIG_2 via RNA interference (RNAi) was used to study its function. RNAi of DhFIG_2 significantly decreased its expression, severely reduced conidiation and trap formation, and affected vegetative growth and stress responses, suggesting that this component of LACS is crucial for trap formation and conidiation in NTF. Our study demonstrated the utility of RNAi assisted by ATMT for studying gene function in D. haptotyla.

Proposal of a new family Pseudodiploösporeaceae fam. nov. (Hypocreales) based on phylogeny of Diploöspora longispora and Paecilomyces penicillatus.

During a field survey of cultivated Morchella mushroom diseases, Diploöspora longispora and Paecilomyces penicillatus, causal agents of pileus rot or white mould disease were detected, which resulted in up to 80% of yield losses. Multi-locus phylogenic analysis revealed that the fungi were affiliated in a distinct clade in Hypocreales. We further constructed a phylogenetic tree with broader sampling in Hypocreales and estimated the divergence times. The D. longispora and P. penicillatus clades were estimated to have diverged from Hypocreaceae around 129 MYA and Pseudodiploösporeaceae fam. nov is herein proposed to accommodate species in this clade. Two new genera, i.e. Pseudodiploöspora and Zelopaecilomyceswere, were introduced based on morphological characteristics and phylogenic relationships of Diploöspora longispora and Paecilomyces penicillatus, respectively. Five new combinations - Pseudodiploöspora cubensis, P. longispora, P. fungicola, P. zinniae, and Zelopaecilomyces penicillatus - were proposed.

Erratum to: Developmental recording of the ghost-moth larvae after ex situ infection by Ophiocordyceps sinensis.

This paper contains errors in the authors' affiliations. Wenjia Li, is a Ph.D. candidate in the University of Chinese Academy of Sciences, Jiangchun Wei and Xingzhong Liu are professors in the University of Chinese Academy of Sciences, which is missing in the original version. The affiliations have been corrected.

Altersteroids A-D, 9,11-Secosteroid-Derived γ-Lactones from an Alternaria sp.

Altersteroids A-D (1-4), four new 9,11-secosteroid-derived γ-lactones, were isolated from cultures of the ascomycete fungus Alternaria sp. Their structures were elucidated primarily by NMR experiments. The absolute configuration of 1 was established by X-ray crystallographic analysis of its di-p-nitrobenzenesulfonate 1a using Cu Kα radiation, whereas those for 2-4 were assigned by quantum-chemical calculations. Compounds 1-4 incorporate a γ-lactone moiety fused to the steroid D ring at C-13/C-14. Compound 3 showed moderate cytotoxicity toward four tumor cell lines and induced an apoptotic process in A549 cells. Notably, compound 3 showed equipotent activity against the cisplatin-sensitive MB49 and -resistant MB49 CisR cells, with an IC50 value of 12.7 µM.