Search

Antioxidant molecules play a crucial role in maintaining redox homeostasis, eliminating oxidative damage, and regulating pathogenesis in phytopathogenic fungi. These antioxidants function through a complex regulatory network involving enzymatic scavengers such as the superoxide dismutases (SODs), catalases, thioredoxins, and glutathiones, as well as non-enzymatic molecules. Specifically, the thioredoxin and glutathione systems (AaTrr1, AaTsa1, AaGpx3, and AaGlr1) mediated by NADPH oxidase represent vital thiol antioxidant systems utilized to regulate the detoxification of reactive oxygen species (ROS) in Alternaria alternata. This present study investigated the regulatory roles of AaBemA, a component of the fungal NADPH oxidase (Nox) complex, in the tangerine pathotype of A. alternata. Loss-of-function genetic analysis demonstrated that AaBemA is essential for the accumulation of cellular hydrogen peroxide (H2O2). Mutant strains with defective AaBemA displayed higher sensitivity to H2O2 and the ROS-generating oxidant tert-butyl-hydroperoxide. These phenotypes closely resembled those previously observed in AaNoxB, AaTrr1, AaTsa1, AaGlr1, and AaYap1 mutants, suggesting a potential interconnection among them. Notably, the defective phenotype of ΔAaBemA could be restored through genetic complementation with wildtype AaBemA gene. Subcellular localization of a functional AaBemA fused with green fluorescent protein (GFP) gene under confocal microscope revealed a widespread distribution of green fluorescence in the cytoplasm and cell membrane, indicating high expression of AaBemA during fungal growth in A. alternata. Intriguingly, inactivation of AaBemA did not affect the morphological phenotype and pathogenicity, indicating that the AaBemA is dispensable for the aforementioned phenotypes. To explore the molecular mechanisms underlying the regulation of ROS stress response, we sequenced the whole transcriptomes of A. alternata wildtype and ROS-sensitive mutants (ΔAaBemA, ΔAaNoxB, ΔAaGlr1, ΔAaTrr1, ΔAaTsa1, ΔAaYap1) which displayed considerable sensitivity to oxidants. Comparative transcriptome analysis revealed significant influence on the gene-expression pattern of numerous genes related to glutathione metabolism, cellular oxidant detoxification, cellular response to abiotic stimulus, and cellular response to osmotic stress. The gene-expression data and pathways related to various essential metabolic processes and ROS tolerance enabled us to propose a NADPH oxidase-mediated regulatory network involving NADPH oxidase (AaNoxB, AaBemA), AaYap1, glutaredoxin (AaGPx3, AaGlr1), and thioredoxin systems (AaTrr1, AaTsa1) in responding to ROS stress in A. alternata. [ABSTRACT FROM AUTHOR]

To analyze the genetic structure and genetic diversity of Colletotrichum gloeosporioides as the dominant Colletotrichum species on Citrus, the Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genetic diversity, including 63 strains isolated and selected from 8 different sites and 5 different citrus species, was studied. A total of 19 GAPDH haplotypes were identified by genetic analysis, and the main haplotype (haplotype 5) was distributed in 28 isolates, mainly from Citrus unchiu Hort. ex Tanaka (WG) and Citrus reticulata Blanco cv. Succosa (BDZ) in Huangyan (HY), Linhai (LH), and Jiande (JD) of Zhejiang province, and Mashui tangerine (MSJ) in Mengshan of Guangxi province (GX). Using the genetic differentiation index, Fst revealed significant genetic differentiation in C. gloeosporioides populations between Jiangxi province (JXGZ) and GX, HY, LH, JD, and Chun'an (CA) of Zhejiang province, and also revealed slightly less genetic differentiation for C. gloeosporioides populations between HY, LH, JD, GX, Shaanxi province (SX), and Quzhou (QZ) of Zhejiang province. In addition, Fst revealed great genetic differentiation between the C. gloeosporioides populations obtained from MSJ and Citrus paradise Macf (PTY), and also revealed weak genetic differentiation between the C. gloeosporioides populations obtained from Citrus sinensis Osbeck (QC), WG, and BDZ. The AMOVA test showed that the levels of genetic differentiation for C. gloeosporioides were 19% and 81% among and within geographic populations, respectively. It also showed that C. gloeosporioides had levels of genetic differentiation among and within host populations of 12% and 88%, respectively. The Mantel test showed that the genetic distance was not linearly correlated with geographical distance and the haplotype phylogenetic analysis showed that C. gloeosporioides from different regions and hosts were scattered in the phylogenetic tree, implying that the genetic differentiation was independent of host variety and geographical origin. We speculated that genetic differentiation may be mainly due to gene mutation, gene recombination, or gene migration within native populations and has nothing to do with natural selection triggered by geography or host variety. [ABSTRACT FROM AUTHOR]

Plectasin is a promising and potent antimicrobial peptide isolated from the fungus Pseudoplectania nigrella which has been heterologously expressed in various hosts. In this study, a four-copy cassette of plectasin was constructed via 2A peptide assembly to further increase its expression level in recombinant Pichia pastoris. The yeast transformant 4Ple-61 harboring four-copy cassette of plectasin could secrete 183.2 mg/L total protein containing 60.8% of plectasin at the flask level within 120 h, which was 2.3 times higher than that of the yeast transformant Ple-6 carrying one-copy cassette of plectasin. Western blot confirmed the significant peptide expression level in the transformant 4Ple-61. Furthermore, it yielded as high as 426.3 mg/L total protein within 120 h during a 5-L fermentation. The purified plectasin shows superior stability and good antimicrobial activity against conventional Staphylococcus aureus ATCC 26,001 and some food-borne antibiotic-resistant S. aureus strains with the MICs ranging from 8 to 32 μg/mL. Therefore, the strategy based on 2A peptide assembly can enhance the expression of plectasin and further expand its application prospect. Key points: • A yeast transformant 4Ple-61 with four-copy cassette of plectasin was constructed. • The plectasin level yield by the transformant 4Ple-61 was boosted by 2.3 times. • The plectasin showed good activity against food-borne antibiotic-resistant S. aureus. [ABSTRACT FROM AUTHOR]

Reinforcement learning, as an effective method to solve complex sequential decision-making problems, plays an important role in areas such as intelligent decision-making and behavioral cognition. It is well known that the sample experience replay mechanism contributes to the development of current deep reinforcement learning by reusing past samples to improve the efficiency of samples. However, the existing priority experience replay mechanism changes the sample distribution in the sample set due to the higher sampling frequency assigned to a specific transition, and it cannot be applied to actor-critic and other on-policy reinforcement learning algorithm. To address this, we propose an adaptive factor based on TD-error, which further increases sample utilization by giving more attention weight to samples of larger TD-error, and embeds it flexibly into the original Deep Q Network and Advantage Actor-Critic algorithm to improve their performance. Then we carried out the performance evaluation for the proposed architecture in the context of CartPole-V1 and 6 environments of Atari game experiments, respectively, and the obtained results either on the conditions of fixed temperature or annealing temperature, when compared to those produced by the vanilla DQN and original A2C, highlight the advantages in cumulative rewards and climb speed of the improved algorithms. [ABSTRACT FROM AUTHOR]

Nonalcoholic fatty liver disease (NAFLD) is considered a risk factor for cardiovascular and cerebrovascular disease owing to its close association with coagulant disturbances. However, the precise biological functions and mechanisms that connect coagulation factors to NAFLD pathology remain inadequately understood. Herein, with unbiased bioinformatics analyses followed by functional testing, we demonstrate that hepatic expression of coagulation factor VII (FVII) decreases in patients and mice with NAFLD/nonalcoholic steatohepatitis (NASH). By using adenovirus-mediated F7 -knockdown and hepatocyte-specific F7 -knockout mouse models, our mechanistic investigations unveil a noncoagulant function of hepatic FVII in mitigating lipid accumulation and lipotoxicity. This protective effect is achieved through the suppression of fatty acid uptake, orchestrated via the AKT-CD36 pathway. Interestingly, intracellular FVII directly interacts with AKT and PP2A, thereby promoting their association and triggering the dephosphorylation of AKT. Therapeutic intervention through adenovirus-mediated liver-specific overexpression of F7 results in noteworthy improvements in liver steatosis, inflammation, injury, and fibrosis in severely afflicted NAFLD mice. In conclusion, our findings highlight coagulation factor FVII as a critical regulator of hepatic steatosis and a potential target for the treatment of NAFLD and NASH. Article Highlights: Coagulation factor VII (FVII) abundance is significantly decreased during nonalcoholic fatty liver disease and negatively correlated with nonalcoholic fatty liver disease progression. Hepatic F7 deficiency exacerbates high-fat diet–induced liver steatosis. Deficiency of F7 accelerates fatty acid uptake via AKT-mediated CD36 upregulation in hepatocytes. FVII directly interacts with PP2A and AKT, triggering the dephosphorylation of AKT by PP2A. Hepatocyte-specific overexpression of F7 ameliorates liver steatosis. [ABSTRACT FROM AUTHOR]

A SiO 2 /Al 2 O 3 -coated electrospun PI membrane was prepared by means of simple dip coating of Al 2 O 3 and SiO 2 mixture onto electrospun PI membrane. The electrochemical performance of the membrane was tested as a separator in the lithium-ion batteries and compared with those of PI membrane, Al 2 O 3 -coated PI membrane, SiO 2 -coated PI membrane, trilayer SiO 2 /Al 2 O 3 -coated PI membraneand Celgard 2400 separators. The SiO 2 /Al 2 O 3 -coated electrospun PI membrane exhibits the best electrochemical performance, including the cycling performance and rate capability. The optical mass ratio of SiO 2 /Al 2 O 3 was 2:1. The SiO 2 component on the interface decrease the interface resistance. Meanwhile, Al 2 O 3 component increase the ionic conductivity. Owing to the intrinsic thermal stability of ceramic materials and PI, the composite membrane doesn’t have the thermal shrinkage problem of commercial separators. [ABSTRACT FROM AUTHOR]

The present study provides a comprehensive overview of the Bacillus velezensis strain Htq6, and its potential applications in plant disease control. Htq6 is an endophytic bacterium derived from walnut, which was found to possess a strong inhibitory effect on a wide range of plant pathogenic microorganisms and was identified as a good plant disease control agent. The entire genome of the Bacillus velezensis Htq6 was sequenced, and a comparative genomic analysis was conducted with various Bacillus species in order to better understand the mechanism of the strain's biological control. At the same time, a new classification result was presented. Additionally, transcriptome analysis was performed to explore the response mechanism of tomato gray mold fungus after treatment with the fermentation liquid of Bacillus velezensis Htq6. The study analyzed the distribution of various secondary metabolite gene clusters in the Bacillus model strains and employed RNA-Seq technology to obtain transcriptome expression profiles. Furthermore, the cell wall, cell membrane, and antioxidant-related genes of Botrytis cinerea were analyzed, providing insight into the antibacterial mechanism of biocontrol bacteria and the stress response mechanism of Botrytis cinerea. The results of the research are promising, and could potentially lead to the development of an effective biocontrol agent for the prevention and control of various plant diseases. [ABSTRACT FROM AUTHOR]

Network embedding technology transforms network structure into node vectors, which reduces the complexity of representation and can be effectively applied to tasks such as classification, network reconstruction and link prediction. The main concern of network embedding is to keep the local structural features while effectively capturing the global features of the network. The "shallow" network representation models cannot capture the deep nonlinear features of the network, and the generated network embedding is usually not the optimal solution. In this paper, a new graph autoencoder-based network representation model combines the first- and second-order proximity to evaluate the performance of network embedding. Aiming at the shortcomings of existing network representation methods in weighted and directed networks, on one hand, the concepts of receiving vector and sending vector are introduced with a simplification of decoding part of the neural network which reduces computation complexity; on the other hand, a measurement index based on node degree is proposed to better emphasize the weighted information in the application of network representation. Experiments including directed weighted networks and undirected unweighted networks show that the proposed method achieves better results than the baseline methods for network reconstruction and link prediction tasks and is of higher computation efficiency than previous graph autoencoder algorithms. Besides, the proposed weighted index is able to improve performances of all baseline methods as an external assistance. [ABSTRACT FROM AUTHOR]

A block copolymer brush based on functional monomers (N -succinimidyl acrylate and N -adamantylacrylamide) successfully grew on the surface of Fe 3 O 4 @SiO 2 nanoparticles by surface-initiated reversible addition-fragmentation chain transfer polymerization (SI-RAFT). According to the multiple recognition mechanisms of this material, horseradish peroxidase (HRP) and β-cyclodextrin-modified glucose oxidase (GOx-CD) were constructed into a multienzyme system with an ordered distribution for the cascade reaction, where multifunctional polymer brush-grafted magnetic nanoparticles were used as the scaffolds. The catalytic activity of GOx-CD was enhanced compared with free GOx. In addition to being easily recycled, this multienzyme system exhibited an outstanding conditional stability compared with the free enzyme system. After being reused 8 times, the activity of multienzyme system retained 67.21% of the initial catalytic activity. This strategy provides a novel idea for reusable ordered enzyme immobilization. [ABSTRACT FROM AUTHOR]

Knot-free timber cultivation is an important goal of forest breeding, and lateral shoots affect yield and stem shape of tree. The purpose of this study was to analyze the molecular mechanism of lateral bud development by removing the apical dominance of Pinus massoniana young seedlings through transcriptome sequencing and identify key genes involved in lateral bud development. We analyzed hormone contents and transcriptome data for removal of apical dominant of lateral buds as well as apical and lateral buds of normal development ones. Data were analyzed using an comprehensive approach of pathway- and gene-set enrichment analysis, Mapman visualization tool, and gene expression analysis. Our results showed that the contents of auxin (IAA), Zea and strigolactone (SL) in lateral buds significantly increased after removal of apical dominance, while abscisic acid (ABA) decreased. Gibberellin (GA) metabolism, cytokinin (CK), jasmonic acid, zeatin pathway-related genes positively regulated lateral bud development, ABA metabolism-related genes basically negatively regulated lateral bud differentiation, auxin, ethylene, SLs were positive and negative regulation, while only A small number of genes of SA and BRASSINOSTEROID, such as TGA and TCH4, were involved in lateral bud development. In addition, it was speculated that transcription factors such as WRKY, TCP, MYB, HSP, AuxIAA, and AP2 played important roles in the development of lateral buds. In summary, our results provided a better understanding of lateral bud differentiation and lateral shoot formation of P. massoniana from transcriptome level. It provided a basis for molecular characteristics of side branch formation of other timber forests, and contributed to knot-free breeding of forest trees. [ABSTRACT FROM AUTHOR]

Host-pathogen interactions are the result of the continuously evolving dynamics of the genomic interphases between pathogens and the host plants. Alternaria brown spot (ABS) caused by the pathogen Alternaria alternata is a serious threat to tangerine production. Although recent studies have made significant advances in the characterization of A. alternata virulence factors, a gap exists in the regulation of virulent genes throughout the course of A. alternata infection on host plants. To gain a better understanding of the dynamic defense transcriptome in Alternaria alternata during Infection, we performed a comparative transcriptome approach. After inoculation on citrus, we found that 2142, 1964, 2359 genes were up-regulated, and 1948, 1434, 1996 genes were down-regulated at 12 hours-post-inoculation (hpi), 24 hpi and 48 hpi, respectively. Among these genes, 1333 genes were up-regulated at three time points, and 1054 genes were down-regulated, indicating that most of the differentially expressed genes at the early stage of infection tended to remain differentially expressed at the later stage of infection. In addition to the genes that are known to be part of the infection network in plant-pathogen interactions, many novel genes related to plant-pathogen interaction were identified. Interestingly, our results indicate that A. alternata is able to rapidly alter its gene expression pattern during infection process, which is vital for the successful colonization of the pathogen. Moreover, this rapid alteration of gene expression is likely to be an adaptive mechanism, enabling the pathogen to quickly respond to any changes in the environment and adapt to the host's defense system. This ability to modify gene expression quickly in the face of environmental changes could play a critical role in the successful establishment of infection. RT-qPCR analysis confirmed that the expression pattern of nine randomly selected genes from the peroxisome pathway were consistent with the RNA-seq data. Our study provided a comprehensive study of the expression of genes during A. alternata infection of citrus, which may facilitate the understanding of host-plant interactions in A. alternata. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel marine-derived α- l -fucosidase OUC-Jdch16 was cloned and characterized. • The OUC-Jdch16 was applied to produce 2′-FL with the highest yield of 92.15%. • Other novel glycosides were prepared via the OUC-Jdch16. 2′-Fucosyllactose (2′-FL) is one of the nutrient ingredients in human milk, which has various beneficial health effects. α- l -fucosidase is a biotechnological tool for 2′-FL preparation. Here, a novel and efficient α- l -fucosidase OUC-Jdch16 from the fucoidan-digesting strain Flavobacterium algicola 12076 was heterologously expressed and applied to produce 2′-FL in vitro. OUC-Jdch16 belongs to glycoside hydrolases (GH) family 29 and exhibits the highest 4-nitrophenyl-α- l -fucopyranoside-hydrolyzing activity at 25 °C and pH 6.0. OUC-Jdch16 could catalyze the synthesis of 2′-FL via transferring the fucosyl residue from pNP-α-fucose to lactose. Under the optimal transfucosylation conditions, the yield of the transfucosylation product reached 84.82% and 92.15% (mol/mol) from pNP-α-fucose within 48 h and 120 h, respectively. Moreover, OUC-Jdch16 was capable of transferring the fucosyl residue to other glycosyl receptors with the generation of novel fucosylated compounds. This study demonstrated that OUC-Jdch16 could be a promising tool to prepare 2′-FL and other novel glycosides. [ABSTRACT FROM AUTHOR]

Pangolins are threatened placental mammals distributed in Africa and Asia. Many efforts have been undertaken in the last century to maintain pangolins in captivity, but only a few of them succeeded in maintaining and keeping this species in a controlled environment. This study reports the first systematic breeding of the Critically Endangered Malayan pangolin (Manis javanica) in captivity. Our captive breeding approach successfully improved the reproductive rate for both wild and captive-born female pangolins. From 2016 to 2020, we had 33 wild pangolins and produced 49 captive-born offspring spanning three filial generations. The female offspring further bred 18 offspring, of which 14 (78%) were conceived during the first time of cohabitation with males, and four offspring were conceived during the second cohabitation event, suggesting that they may practice copulation-induced ovulation. We observed that captive-born female pangolins could reach sexual maturity at 7–9 months (n = 4), and male pangolins could mate and successfully fertilise females at nine months age (n = 1). We also observed a female pangolin conceiving on the eighth day after parturition (the fifth day after the death of its pup). Our captive pangolins had a female-biased sex ratio of 1:0.5 at birth, unlike other known captive-born mammals. Also, captive-born pangolins were generally more viable after successful weaning and had a similar gestation length (~185 days) to wild pangolins. Most importantly, we report the first self-sustaining captive population of Malayan pangolins, and this species has an efficient reproduction strategy. These advances provide more comprehensive information for people to understand pangolins, and have implications for conserving endangered Malayan pangolins and providing scientific guidance to the management of other pangolin species. Yan et al. report on a successful captive breeding program for Critically Endangered Malayan pangolins, Manis javanica. Breeding pangolins in captivity is historically challenging and unsuccessful, highlighting the importance of this self-sustaining population. [ABSTRACT FROM AUTHOR]

Abstract Using polystyrene (PS) microspheres as an auxiliary template, a kind of novel gully-like Sr-doped ZrO 2 –TiO 2 composites with the heterogeneous structure were successfully prepared by a simple instant centrifugation with one-step hydrolysis method. The Sr-doped ZrO 2 –TiO 2 composites consisted of the tetragonal phase ZrO 2 , orthogonal phase SrZrO 3 and anatase phase TiO 2 , showing a homogeneous concave and convex shape, similared to the naturally occurring gully terrain in nature, with a double-sized mesoporous structure. The SrZrO 3 was prepared by the synthetic method in this study, which provided a new reference for the subsequent synthesis of SrZrO 3. At the same time, Sr-doped ZrO 2 –TiO 2 composites showed higher photocatalytic activity compared with the monomer and non-strontium-doped TiO 2 -ZrO 2 under multi-mode photocatalytic conditions such as ultraviolet light, visible light, and simulated sunlight. The hydrogen production of Sr-doped ZrO 2 –TiO 2 was 2.9 times and 4.4 times higher than that of TiO 2 –ZrO 2 and TiO 2 , indicating that Sr-doped played a synergistic role in photocatalytic activity experiments. Finally, by the capturing experiment of gully-like Sr-doped ZrO 2 –TiO 2 , it was confirmed that h+,·OH, O 2 •− were active species in the photodegradation of malachite green, and the possible mechanism of the photocatalytic reaction was deduced. Graphical abstract Using polystyrene(PS) microspheres as the template, gully-like Sr-doped ZrO 2 –TiO 2 composite was synthesized by simple instant centrifugation with one-step hydrolysis combined with vacuum and calcination post-processing method, in which gully-like Sr-doped ZrO 2 –TiO 2 exhibited superior photocatalytic degradation efficiency and enhanced activity in splitting water into hydrogen. fx1 [ABSTRACT FROM AUTHOR]

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

Link prediction in social networks has become a growing concern among researchers. In this paper, the clustering method was used to exploit the grouping tendency of nodes, and a clustering index (CI) was proposed to predict potential links with characteristics of scientific cooperation network taken into consideration. Results showed that CI performed better than the traditional indices for scientific coauthorship networks by compensating for their disadvantages. Compared with traditional algorithms, this method for a specific type of network can better reflect the features of the network and achieve more accurate predictions. [ABSTRACT FROM AUTHOR]