Prevalence and Evolutionary Characteristics of Bovine Coronavirus in China.

Bovine coronavirus (BCoV), bovine rotavirus, bovine viral diarrhea virus, and bovine astrovirus are the most common intestinal pathogenic viruses causing diarrhea in cattle. We collected 1646 bovine fecal samples from January 2020 to August 2023. BCoV was the major pathogen detected, with a positive rate of 34.02% (560/1646). Of the 670 diarrheal samples and 976 asymptomatic samples, 209 and 351 were BCoV-positive, respectively. Studying the relevance of diarrhea associated with BCoV has shown that the onset of diarrheal symptoms post-infection is strongly correlated with the cattle's age and may also be related to the breed. We amplified and sequenced the hemagglutinin esterase (HE), spike protein, and whole genomes of the partially positive samples and obtained six complete HE sequences, seven complete spike sequences, and six whole genomes. Molecular characterization revealed that six strains were branched Chinese strains, Japanese strains, and partial American strains from the GⅡb subgroup. Strains HBSJZ2202 and JSYZ2209 had four amino acid insertions on HE. We also analyzed ORF1a and found disparities across various regions within GIIb, which were positioned on separate branches within the phylogenetic tree. This work provides data for further investigating the epidemiology of BCoV and for understanding and analyzing BCoV distribution and dynamics.

Control of Fusarium Head Blight of Wheat with Bacillus velezensis E2 and Potential Mechanisms of Action.

Wheat plants are impacted by Fusarium head blight (FHB) infection, which poses a huge threat to wheat growth, development, storage and food safety. In this study, a fungal strain was isolated from diseased wheat plants and identified as Fusarium asiaticum F1, known to be a member of the Fusarium graminearum species complex, agents causally responsible for FHB. In order to control this disease, new alternatives need to be developed for the use of antagonistic bacteria. Bacillus velezensis E2 (B. velezensis E2), isolated from a previous investigation in our laboratory, showed a notable inhibitory effect on F. asiaticum F1 growth and deoxynivalenol (DON) synthesis in grains. The spore germination of F. asiaticum F1 was significantly reduced and the spores showed vesicular structures when treated with B. velezensis E2. Observations using scanning electron microscopy (SEM) showed that the hyphae of F. asiaticum F1 were shrunken and broken when treated with B. velezensis E2. The RNA-seq results of F1 hyphae treated with B. velezensis E2 showed that differentially expressed genes (DEGs), which were involved in multiple metabolic pathways such as toxin synthesis, autophagy process and glycan synthesis, especially the genes associated with DON synthesis, were significantly downregulated. In summary, those results showed that B. velezensis E2 could inhibit F. asiaticum F1 growth and reduce the gene expression of DON synthesis caused by F1. This study provides new insights and antagonistic mechanisms for the biological control of FHB during wheat growth, development and storage.

Nsp10-interacting host protein SAP18 restricts PEDV replication in Marc-145 cells via enhancing dephosphorylation of RIG-I.

PEDV, a single-stranded RNA virus, causes significant economic losses in the pig industry. Sin3-associated protein 18 (SAP18) is known for its role in transcriptional inhibition and RNA splicing. However, research on SAP18's involvement in PEDV infection is limited. Here, we identified an interaction between SAP18 and PEDV nonstructural protein 10 (Nsp10) using immunoprecipitation-mass spectrometry (IP-MS) and confirmed it through immunoprecipitation and laser confocal microscopy. Additionally, PEDV Nsp10 reduced SAP18 protein levels and induced its cytoplasmic accumulation. Overexpressing SAP18 suppressed PEDV replication, meanwhile its knockdown via short interfering RNA (siRNA) enhanced replication. SAP18 overexpression boosted IRF3 and NF-κB P65 phosphorylation, nuclear translocation, and IFN-ß antiviral response. Furthermore, SAP18 upregulated RIG-I expression and facilitated its dephosphorylation, while SAP18 knockdown had the opposite effect. Finally, SAP18 interacted with phosphatase 1 (PP1) catalytic subunit alpha (PPP1CA), promoting PPP1CA-RIG-I interaction during PEDV infection. These findings highlight SAP18's role in activating the type I interferon pathway and inhibiting viral replication by promoting RIG-I dephosphorylation through its interaction with PPP1CA.

Composite attention mechanism network for deep contrastive multi-view clustering.

Contrastive learning-based deep multi-view clustering methods have become a mainstream solution for unlabeled multi-view data. These methods usually utilize a basic structure that combines autoencoder, contrastive learning, or/and MLP projectors to generate more representative latent representations for the final clustering stage. However, existing deep contrastive multi-view clustering ignores two key points: (i) the latent representations projecting from one or more layers of MLP or new representations directly obtained from autoencoder fail to mine inherent relationship inner-view or cross-views; (ii) more existing frameworks only employ a one or dual-contrastive learning module, i.e., view- or/and category-oriented, which may result in the lack of communication between latent representations and clustering assignments. This paper proposes a new composite attention framework for contrastive multi-view clustering to address the above two challenges. Our method learns latent representations utilizing composite attention structure, i.e., Hierarchical Transformer for each view and Shared Attention for all views, rather than simple MLP. As a result, the learned representations can simultaneously preserve important features inside the view and balance the contributions across views. In addition, we add a new communication loss in our new dual contrastive framework. The common semantics will be brought into clustering assignments by pushing clustering assignments closer to the fused latent representations. Therefore, our method will provide a higher quality of clustering assignments for the segmentation problem of unlabeled multi-view data. The extensive experiments on several real data demonstrate that the proposed method can achieve superior performance over many state-of-the-art clustering algorithms, especially the significant improvement of an average of 10% on datasets Caltech and its subsets according to accuracy.

A novel recombination porcine epidemic diarrhea virus isolated from Gansu, China: Genetic characterization and pathogenicity.

Porcine epidemic diarrhea virus (PEDV) is an acute and highly contagious porcine enteric coronavirus. It has caused serious economic losses of pig industry in China. Here we insolated a current PEDV field strain named GS2022, analyzed the characters of genetic variation and pathogenicity. The results demonstrated that the GS2022 strain was belong to a newly defined subgroup G2 d, forming an independent branch which mainly contains strains isolated in China from 2017 to 2023. Notably, there are multiple mutations and extensive N-glycosylation compared to CV777 strain and PT-P5 strain, therefore the structure of GS2022 strain is different from 6U7K and 7W6M. Animal pathogenicity test showed that GS2022 strain could cause severe clinical signs and the high level of virus shedding in 7-day-old piglets. But recovery of diarrhea after 5 days, and no pathological damage to important organs. Further study on 3-day-old piglets also indicated GS2022 strain have pathogenicity. In this study no piglets died, which make it possible for that GS2022 strain become a candidate vaccine. These results are helpful to understand the epidemiology, molecular characteristics, evolution, and antigenicity of PEDV circulating in China. It also provides reference for designing effective vaccines against PEDV.

PEDV inhibits HNRNPA3 expression by miR-218-5p to enhance cellular lipid accumulation and promote viral replication.

Porcine epidemic diarrhea virus (PEDV) requires complete dependence on the metabolic system of the host cell to complete its life cycle. There is a strong link between efficient viral replication and cellular lipid synthesis. However, the mechanism by which PEDV interacts with host cells to hijack cellular lipid metabolism to promote its replication remains unclear. In this study, PEDV infection significantly enhanced the expression of lipid synthesis-related genes and increased cellular lipid accumulation. Furthermore, using liquid chromatography-tandem mass spectrometry, we identified heterogeneous nuclear ribonucleoprotein A3 (HNRNPA3) as the interacting molecule of PEDV NSP9. We demonstrated that the expression of HNRNPA3 was downregulated by PEDV-induced miR-218-5p through targeting its 3' untranslated region. Interestingly, knocking down HNRNPA3 facilitated the PEDV replication by promoting cellular lipid synthesis. We next found that the knockdown of HNRNPA3 potentiated the transcriptional activity of sterol regulatory element-binding transcription factor 1 (SREBF1) through zinc finger protein 135 (ZNF135) as well as PI3K/AKT and JNK signaling pathways. In summary, we propose a model in which PEDV downregulates HNRNPA3 expression to promote the expression and activation of SREBF1 and increase cellular lipid accumulation, providing a novel mechanism by which PEDV interacts with the host to utilize cellular lipid metabolism to promote its replication.IMPORTANCEAs the major components and structural basis of the viral replication complexes of positive-stranded RNA viruses, lipids play an essential role in viral replication. However, how PEDV manipulates host cell lipid metabolism to promote viral replication by interacting with cell proteins remains poorly understood. Here, we found that SREBF1 promotes cellular lipid synthesis, which is essential for PEDV replication. Moreover, HNRNPA3 negatively regulates SREBF1 activation and specifically reduces lipid accumulation, ultimately inhibiting PEDV dsRNA synthesis. Our study provides new insight into the mechanisms by which PEDV hijacks cell lipid metabolism to benefit viral replication, which can offer a potential target for therapeutics against PEDV infection.

Bovine herpesvirus-1 gE protein inhibits IFN-ß production to enhance replication by promoting MAVS ubiquitination and interfering with the interaction between IRF3 and CBP/p300.

Bovine herpesvirus-1 (BoHV-1) can infect all breeds of cattle and cause respiratory and genital tract diseases. In the process of viral infection, viruses can use their own proteins to suppress the innate immunity of the host and promote its replication; however, the mechanism by which BoHV-1 evades the innate immune response is not fully understood. In this study, we found that rabbits inoculated with the live gene deletion vaccine BoHV-1-△gI/gE/TK generated higher interferon-ß (IFN-ß) production in the serum, liver, lung and kidney than rabbits inoculated with wt BoHV-1, which led to milder lesions in the lung and kidney. We performed gene deletion and ectopic expression experiments on viral proteins and found that gE was the major protein that inhibited IFN-ß expression. Further studies showed that MAVS and IRF3 were the targets of gE, and the specific mechanism was that gE inhibited IFN-ß production by promoting MAVS ubiquitination and interfering with the interaction between IRF3 and CBP/p300. These results suggest a new way of BoHV-1 inhibition of IFN-ß production to evade the host innate immunity.

The novel Nsp9-interacting host factor H2BE promotes PEDV replication by inhibiting endoplasmic reticulum stress-mediated apoptosis.

Porcine epidemic diarrhoea (PED) caused by porcine epidemic diarrhoea virus (PEDV) has led to significant economic losses in the swine industry worldwide. Histone Cluster 2, H2BE (HIST2H2BE), the main protein component in chromatin, has been proposed to play a key role in apoptosis. However, the relationship between H2BE and PEDV remains unclear. In this study, H2BE was shown to bind and interact with PEDV nonstructural protein 9 (Nsp9) via immunoprecipitation-mass spectrometry (IP-MS). Next, we verified the interaction of Nsp9 with H2BE by immunoprecipitation and immunofluorescence. H2BE colocalized with Nsp9 in the cytoplasm and nuclei. PEDV Nsp9 upregulated the expression of H2BE by inhibiting the expression of IRX1. We demonstrated that overexpression of H2BE significantly promoted PEDV replication, whereas knockdown of H2BE by small interfering RNA (siRNA) inhibited PEDV replication. Overexpression of H2BE led to significantly inhibited GRP78 expression, phosphorylated PERK (p-PERK), phosphorylated eIF2 (p-eIF2), phosphorylated IRE1 (p-IRE1), and phosphorylated JNK (p-JNK); negatively regulated CHOP and Bax expression and caspase-9 and caspase-3 cleavage; and promoted Bcl-2 production. Knocking down H2BE exerted the opposite effects. Furthermore, we found that after deletion of amino acids 1-28, H2BE did not promote PEDV replication. In conclusion, these studies revealed the mechanism by which H2BE is associated with ER stress-mediated apoptosis to regulate PEDV replication. Nsp9 upregulates H2BE. H2BE plays a role in inhibiting apoptosis and thus facilitating viral replication, which depends on the N-terminal region of H2BE (amino acids 1-28). These findings provide a reference for host-PEDV interactions and offer the possibility for developing strategies for PEDV decontamination and prevention.

GRAMD4 regulates PEDV-induced cell apoptosis inhibiting virus replication via the endoplasmic reticulum stress pathway.

Porcine epidemic diarrhea (PED) caused by the porcine epidemic diarrhea virus (PEDV) has caused huge losses in the swine industry worldwide. Glucosyltransferase Rab-like GTPase activator and myotubularin domain containing 4 (GRAMD4) is a proapoptotic protein, which replaced p53 inducing mitochondrial apoptosis. However, the relationship between GRAMD4 and PEDV has not been reported. Here, we aimed to investigate the potential role of GRAMD4 during PEDV infection. In this study, we used co-immunoprecipitation (co-IP) and mass spectrometry to identify GRAMD4 interaction with PEDV non-structural protein 6 (NSP6). Immunoprecipitation and laser confocal microscopy were utilized to demonstrate that GRAMD4 interacts with NSP6. NSP6 reduces GRAMD4 production through PERK and IRE1 pathway-mediated apoptosis. We demonstrated that overexpression of GRAMD4 effectively impaired the replication of PEDV, whereas knockdown of GRAMD4 facilitated the replication of PEDV. Overexpression of GRAMD4 increased GRP78, phosphorylated PERK (p-PERK), phosphorylated IRE1(p-IRE1) levels, promoted CHOP, phosphorylated JNK (p-JNK), Bax expression, caspase 9 and caspase 3 cleavage, and inhibited Bcl-2 production. Knockdown of GRAMD4 has the opposite effect. Finally, deletion of the GRAM domain of GRAMD4 cannot cause endoplasmic reticulum stress (ER stress)-mediated apoptosis and inhibit virus replication. In conclusion, these studies revealed the mechanism by which GRAMD4 was associated with ER stress and apoptosis regulating PEDV replication. NSP6 acted as a potential down-regulator of GRAMD4 and promoted the degradation of GRAMD4. GRAMD4 played a role in facilitating apoptosis and restricting virus replication, and the GRAM domain was required. These findings provided a reference for host-PEDV interactions and offered the possibility for PEDV decontamination and prevention.

Heterogeneous Nuclear Protein U Degraded the m6A Methylated TRAF3 Transcript by YTHDF2 To Promote Porcine Epidemic Diarrhea Virus Replication.

Porcine epidemic diarrhea virus (PEDV) belongs to the genus Alphacoronavirus of the Coronaviridae family and can cause fatal watery diarrhea in piglets, causing significant economic losses. Heterogeneous nuclear protein U (HNRNPU) is a novel RNA sensor involved in sensing viral RNA in the nucleus and mediating antiviral immunity. However, it remains elusive whether and how cytoplasmic PEDV can be sensed by the RNA sensor HNRNPU. In this study we determined that HNRNPU was the binding partner of Nsp13 by immunoprecipitation-liquid chromatography-tandem mass spectrometry (IP/LC-MS/MS) analysis. The interaction between Nsp13 and HNRNPU was demonstrated by using coimmunoprecipitation and confocal immunofluorescence. Next, we identified that HNRNPU expression is significantly increased during PEDV infection, whereas the transcription factor hepatocyte nuclear factor 1α (HNF1A) could negatively regulate HNRNPU expression. HNRNPU was retained in the cytoplasm by interaction with PEDV Nsp13. We found that HNRNPU overexpression effectively facilitated PEDV replication, while knockdown of HNRNPU impaired viral replication, suggesting a promoting function of HNRNPU to PEDV infection. Additionally, HNRNPU was found to promote PEDV replication by affecting TRAF3 degradation at the transcriptional level to inhibit PEDV-induced beta interferon (IFN-ß) production. Mechanistically, HNRNPU downregulates TRAF3 mRNA levels via the METTL3-METTL14/YTHDF2 axis and regulates immune responses through YTHDF2-dependent mRNA decay. Together, our findings reveal that HNRNPU serves as a negative regulator of innate immunity by degrading TRAF3 mRNA in a YTHDF2-dependent manner and consequently facilitating PEDV propagation. Our findings provide new insights into the immune escape of PEDV. IMPORTANCE PEDV, a highly infectious enteric coronavirus, has spread rapidly worldwide and caused severe economic losses. During virus infection, the host regulates innate immunity to inhibit virus infection. However, PEDV has evolved a variety of different strategies to suppress host IFN-mediated antiviral responses. Here, we identified that HNRNPU interacted with viral protein Nsp13. HNRNPU protein expression was upregulated, and the transcription factor HNF1A could negatively regulate HNRNPU expression during PEDV infection. HNRNPU also downregulated TRAF3 mRNA through the METTL3-METTL14/YTHDF2 axis to inhibit the production of IFN-ß and downstream antiviral genes in PEDV-infected cells, thereby promoting viral replication. Our findings reveal a new mechanism with which PEDV suppresses the host antiviral response.

Cell entry of Bovine herpesvirus-1 through clathrin- and caveolin-mediated endocytosis requires activation of PI3K-Akt-NF-κB and Ras-p38 MAPK pathways as well as the interaction of BoHV-1 gD with cellular receptor nectin-1.

Bovine herpesvirus-1 (BoHV-1) can infect all breeds of cattle and cause severe respiratory organs and genital tract diseases. However, the mechanism of BoHV-1 entering the cells remains unclear. In this study, we explored the mechanism of BoHV-1 entering MDBK cells. We found that the entry of BoHV-1 was blocked by NH4Cl and bafilomycin A1, indicating that BoHV-1 entry is dependent on the acidic environment of endosome. Specific inhibitor dynasore and small interfering RNA (siRNA) knockdown of dynamin-2 inhibited BoHV-1 entry, showing that dynamin is required in BoHV-1 entry. The results of specific inhibitor, siRNA knockdown and co-localization indicating clathrin- and caveolin- mediated endocytosis play a role in BoHV-1 entry. BoHV-1 infection was not affected by EIPA which is a specific inhibitor of macropinocytosis. In addition, we found that BoHV-1 triggered PI3K-Akt-NF-κB and Ras-p38 MAPK signaling pathways to induce clathrin-mediated and caveolin-mediated endocytosis at the early stage of BoHV-1 infection. BoHV-1 binding was sufficient to activate the endocytic signaling pathways and promote viral entry. These two signaling pathways were activated by transfection of viral gD protein, and were inhibited by deletion of viral gD protein and the siRNA knockdown of cellular receptor nectin-1. The results of co-localization indicating the entered BoHV-1 is traced to late endosomes via early endosomes. Our results suggested the interaction of viral gD protein and cellular receptor nectin-1 triggered the PI3K-Akt-NF-κB and Ras-p38 MAPK signaling pathways and induced clathrin-mediated and caveolin-mediated endocytosis to promote BoHV-1 entry into MDBK cells at the early stage of BoHV-1 infection.

Differential expression analysis of mRNAs, lncRNAs, and miRNAs expression profiles and construction of ceRNA networks in PEDV infection.

BACKGROUND: Porcine Epidemic Diarrhea Virus (PEDV) is a coronavirus that seriously affects the swine industry. MicroRNAs and long noncoding RNAs are two relevant non-coding RNAs (ncRNAs) class and play crucial roles in a variety of physiological processes. Increased evidence indicates a complex interaction between mRNA and ncRNA. However, our understanding of the function of ncRNA involved in host-PEDV interaction is limited. RESULTS: A total of 1,197 mRNA transcripts, 539 lncRNA transcripts, and 208 miRNA transcripts were differentially regulated at 24 h and 48 h post-infection. Gene ontology (GO) and KEGG pathway enrichment analysis showed that DE mRNAs and DE lncRNAs were mainly involved in biosynthesis, innate immunity, and lipid metabolism. Moreover, we constructed a miRNA-mRNA-pathway network using bioinformatics, including 12 DE mRNAs, 120 DE miRNAs, and 11 pathways. Finally, the target genes of DE miRNAs were screened by bioinformatics, and we constructed immune-related lncRNA-miRNA-mRNA ceRNA networks. Then, the selected DE genes were validated by qRT-PCR, which were consistent with the results from RNA-Seq data. CONCLUSIONS: This study provides the comprehensive analysis of the expression profiles of mRNAs, lncRNAs, and miRNAs during PEDV infection. We characterize the ceRNA networks which can provide new insights into the pathogenesis of PEDV.

Identification and picking point positioning of tender tea shoots based on MR3P-TS model.

Tea is one of the most common beverages in the world. In order to reduce the cost of artificial tea picking and improve the competitiveness of tea production, this paper proposes a new model, termed the Mask R-CNN Positioning of Picking Point for Tea Shoots (MR3P-TS) model, for the identification of the contour of each tea shoot and the location of picking points. In this study, a dataset of tender tea shoot images taken in a real, complex scene was constructed. Subsequently, an improved Mask R-CNN model (the MR3P-TS model) was built that extended the mask branch in the network design. By calculating the area of multiple connected domains of the mask, the main part of the shoot was identified. Then, the minimum circumscribed rectangle of the main part is calculated to determine the tea shoot axis, and to finally obtain the position coordinates of the picking point. The MR3P-TS model proposed in this paper achieved an mAP of 0.449 and an F2 value of 0.313 in shoot identification, and achieved a precision of 0.949 and a recall of 0.910 in the localization of the picking points. Compared with the mainstream object detection algorithms YOLOv3 and Faster R-CNN, the MR3P-TS algorithm had a good recognition effect on the overlapping shoots in an unstructured environment, which was stronger in both versatility and robustness. The proposed method can accurately detect and segment tea bud regions in real complex scenes at the pixel level, and provide precise location coordinates of suggested picking points, which should support the further development of automated tea picking machines.

TRIM56 overexpression restricts porcine epidemic diarrhoea virus replication in Marc-145 cells by enhancing TLR3-TRAF3-mediated IFN-ß antiviral response.

Infection with the porcine epidemic diarrhoea virus (PEDV) causes severe enteric disease in suckling piglets, causing massive economic losses in the swine industry worldwide. Tripartite motif-containing 56 (TRIM56) has been shown to augment type I IFN response, but whether it affects PEDV replication remains uncharacterized. Here we investigated the role of TRIM56 in Marc-145 cells during PEDV infection. We found that TRIM56 expression was upregulated in cells infected with PEDV. Overexpression of TRIM56 effectively reduced PEDV replication, while knockdown of TRIM56 resulted in increased viral replication. TRIM56 overexpression significantly increased the phosphorylation of IRF3 and NF-κB P65, and enhanced the IFN-ß antiviral response, while silencing TRIM56 did not affect IRF3 activation. TRIM56 overexpression increased the protein level of TRAF3, the component of the TLR3 pathway, thereby significantly activating downstream IRF3 and NF-κB signalling. We demonstrated that TRIM56 overexpression inhibited PEDV replication and upregulated expression of IFN-ß, IFN-stimulated genes (ISGs) and chemokines in a dose-dependent manner. Moreover, truncations of the RING domain, N-terminal domain or C-terminal portion on TRIM56 were unable to induce IFN-ß expression and failed to restrict PEDV replication. Together, our results suggested that TRIM56 was upregulated in Marc-145 cells in response to PEDV infection. Overexpression of TRIM56 inhibited PEDV replication by positively regulating the TLR3-mediated antiviral signalling pathway. These findings provide evidence that TRIM56 plays a positive role in the innate immune response during PEDV infection.

The CREB and AP-1-Dependent Cell Communication Network Factor 1 Regulates Porcine Epidemic Diarrhea Virus-Induced Cell Apoptosis Inhibiting Virus Replication Through the p53 Pathway.

Porcine epidemic diarrhea virus (PEDV) infection causes severe diarrhea, dehydration, and high mortality in sick pigs, causing huge economic losses to the pig industry. However, the relationship between cell communication network factor 1 (CCN1) and PEDV infection has not been reported. In this study, we showed that the expression of CCN1 was enhanced by PEDV infection, and we observed that PEDV promotes the CREB and AP-1 activation to promote CCN1 expression. The PKA and p38 inhibitors significantly suppress CCN1 expression, indicating that PEDV-induced CCN1 expression may be through PKA and p38 pathway. Further tests confirmed that CREB and AP-1 are regulated by PKA and p38, respectively. Overexpression of CCN1 decreased the replication of PEDV, whereas knockdown of CCN1 increased the replication of PEDV. We proved that the overexpression of CCN1 increased the phosphorylation level of p53, promoted the expresion of Bax and the cleavage of caspase 9 and caspase 3, and inhibited the production of Bcl-2. CCN1 knockdown decreased the phosphorylation level of p53, inhibited the production of Bax and the cleavage of caspase 9 and caspase 3, and promoted the expression of Bcl-2. The treatment of PFT-α (p53 inhibitor) significantly suppressed the expression of cleaved caspase 9 and caspase 3, leading to the decrease of apoptosis. Together, these studies showed that PEDV promotes the activation of CREB and AP-1 to increase the expression of CCN1. Overexpression of CCN1 promotes apoptosis by elevating p53 protein phosphorylation and inhibits PEDV replication, and knockdown of CCN1 inhibits apoptosis by decreasing p53 protein phosphorylation and promotes PEDV replication. Our study could provide some reference for the molecular mechanisms of PEDV-induced CCN1 induction and supply a new therapeutic target for PEDV.

Application of Two-Stage Variable Temperature Drying in Hot Air-Drying of Paddy Rice.

The aim of this study was to investigate the effect of two-stage variable temperature drying (VTD) on the quality and drying efficiency of paddy rice in the hot air-drying process. A constant temperature of 50 °C (CTD) was used as a control group. VTD and CTD methods were applied in a 15 ton batch type recirculating grain dryer. Three aspects (appearance quality, physical and chemical properties, taste quality) of the paddy rice samples from the dryer were measured and compared. It was observed that paddy rice with an initial moisture content of 25.3% (wet basis) was dried to 14% (wet basis). Compared to CTD, the VTD method could reduce the drying time and fissuring rate by 0.7 h and 42%, respectively. It had a head rice yield (HRY) of 78.45%, compared to 76.45% by CTD. The fatty acid content of the VTD samples was 2.28% lower than those of CTD, and it exhibited a 34% decrease in amylose content. These results show that two-stage VTD is an advanced hot air-drying method that can be used to improve the quality of dried paddy rice, maintain efficiency, and reduce the cost of the drying process by minimizing the rate of energy consumption.

Screening of Bacillus velezensis E2 and the Inhibitory Effect of Its Antifungal Substances on Aspergillus flavus.

Aspergilus flavus is the main pathogenic fungus that causes food mold. Effective control of A. flavus contamination is essential to ensure food safety. The lipopeptides (LPs) produced by Bacillus strains have been shown to have an obvious antifungal effect on molds. In this study, an antagonist strain of Bacillus velezensis with obvious antifungal activity against A. flavus was isolated from the surface of healthy rice. Using HPLC-MS analysis, the main components of LPs produced by strain E2 were identified as fengycin and iturins. Further investigations showed that LPs could inhibit the spore germination, and even cause abnormal expansion of hyphae and cell rupture. Transcriptomic analyses showed that some genes, involved in ribosome biogenesis in eukaryotes (NOG1, KRE33) and aflatoxin biosynthesis (aflK, aflR, veA, omtA) pathways in A. flavus were significantly down-regulated by LPs. In conclusion, this study provides novel insights into the cellular and molecular antifungal mechanisms of LPs against grain A. flavus contamination.

Winter Wheat Nitrogen Estimation Based on Ground-Level and UAV-Mounted Sensors.

A better understanding of wheat nitrogen status is important for improving N fertilizer management in precision farming. In this study, four different sensors were evaluated for their ability to estimate winter wheat nitrogen. A Gaussian process regression (GPR) method with the sequential backward feature removal (SBBR) routine was used to identify the best combinations of vegetation indices (VIs) sensitive to wheat N indicators for different sensors. Wheat leaf N concentration (LNC), plant N concentration (PNC), and the nutrition index (NNI) were estimated by the VIs through parametric regression (PR), multivariable linear regression (MLR), and Gaussian process regression (GPR). The study results reveal that the optical fluorescence sensor provides more accurate estimates of winter wheat N status at a low-canopy coverage condition. The Dualex Nitrogen Balance Index (NBI) is the best leaf-level indicator for wheat LNC, PNC and NNI at the early wheat growth stage. At the early growth stage, Multiplex indices are the best canopy-level indicators for LNC, PNC, and NNI. At the late growth stage, ASD VIs provide accurate estimates for wheat N indicators. This study also reveals that the GPR with SBBR analysis method provides more accurate estimates of winter wheat LNC, PNC, and NNI, with the best VI combinations for these sensors across the different winter wheat growth stages, compared with the MLR and PR methods.

Inhibition of DDX6 enhances autophagy and alleviates endoplasmic reticulum stress in Vero cells under PEDV infection.

Porcine epidemic diarrhea (PED), caused by the porcine epidemic diarrhea virus (PEDV), has arisen huge economic losses to the swine industry worldwide. The Asp-Glu-Ala-Asp (DEAD)-box polypeptide 6 (DDX6), a DEAD-box RNA helicase family member, acts as a suppressor of autophagy, however, whether it participates in PEDV-induced autophagy remains unclear. Here, we aimed to investigate the potential role of DDX6 during PEDV infection. We found that DDX6 protein expression was down-regulated and mRNA expression was up-regulated in PEDV-infected cells. Overexpression of DDX6 effectively impaired PEDV replication, while knockdown of DDX6 facilitated viral replication. Overexpression of DDX6 facilitated the degradation of autophagy-related gene (ATG) mRNA and partially rescued the dephosphorylation of mammalian target of rapamycin (mTOR) by PEDV infection. We also found that PEDV-triggered endoplasmic reticulum (ER) stress reduced the protein level of DDX6, and conversely, silencing of DDX6 is necessary and sufficient to alleviate ER stress and cell apoptosis. In addition, the loss of RNA helicase activity on DDX6 lost the ability to suppress autophagy and failed to restrict PEDV replication. Taken together, these findings indicated a DDX6-based mechanism that associates ER stress with autophagy activation during PEDV infection. PEDV-triggered ER stress down-regulated the expression of DDX6 to induce autophagy by inhibiting degradation of ATGs and phosphorylation of mTOR signaling, which alleviates ER stress and Promotes cell survival rather than apoptosis. These findings provided new insight into the function of DDX6 in autophagy during PEDV infection and may serve as a therapeutic strategy for controlling PEDV infection.

Development of multiplex TaqMan qPCR for simultaneous detection and differentiation of eight common swine viral and bacterial pathogens.

It is laborious to diagnose the infections of classical swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), and Suid herpesvirus 1 (SuHV-1) because of the similar clinical symptoms in piglets. Staphylococcus aureus (S. aureus), Streptococcus suis (S. suis), Salmonella choleraesuis (S. choleraesuis, serotype: 6,7:c:1,5), and Escherichia coli (E. coli) are common secondary bacterial pathogens in viral infections. Furthermore, the mixed infection of these viral and bacterial pathogens is more and more common in practical swine breeding. Therefore, a TaqMan multiplex qPCR method for simultaneous detection and differentiation of their pathogen was established in this study by designing specific primers and probes for the E2 gene of CSFV, the ORF7 gene of PRRSV, the ORF1 gene of PCV2 and the gE gene of SuHV-1, the nuc gene of S. aureus, the ef-tu gene of S. suis, the ivnA gene of S. choleraesuis, and the 23S rRNA gene of E. coli, and its specificity, sensitivity, and reproducibility were subsequently tested. The results showed that TaqMan multiplex qPCR method showed a high specificity with no cross reaction between different viruses, and a good repeatability with its coefficient of variation lower than 5%. Besides, the sensitivity of this method was also at least 10 times higher compared with conventional PCR. Overall, this study provided a reliable multiplex TaqMan qPCR method for the diagnosis and differentiation of the mentioned pathogens in pigs, laying a certain technical basis for disease prevention and control.