FoxO1-modulated macrophage polarization regulates osteogenesis via PPAR-γ signaling.

Periodontitis, a common chronic inflammatory disease, epitomizes a significant impairment in the host immune system and an imbalance of bone metabolism. Macrophage polarization, a dynamic process dictated by the microenvironment, intricately contributes to the interplay between the immune system and bone remodeling, namely the osteoimmune system. Forkhead box protein O1 (FoxO1) has been shown to play a dramatic role in mediating oxidative stress, bone mass, as well as cellular metabolism. Nevertheless, the function and underlying mechanisms of FoxO1 in regulating macrophage polarization-mediated osteogenesis in periodontitis remain to be further elucidated. Here, we found that FoxO1 expression was closely linked to periodontitis, accompanied by aggravated inflammation. Notably, FoxO1 knockdown skewed macrophage polarization from M1 to the antiinflammatory M2 phenotype under inflammatory conditions, which rescued the impaired osteogenic potential. Mechanistically, we revealed that the enhancement of the transcription of peroxisome proliferator-activated receptor (PPAR) signaling in FoxO1-knockdown macrophages. In agreement with this contention, GW9662, a specific inhibitor of PPAR-γ signaling, greatly aggravated macrophage polarization from M2 to the M1 phenotype and attenuated osteogenic potential under inflammatory conditions. Additionally, PPAR-γ signaling agonist rosiglitazone (RSG) was applied to address ligature-induced periodontitis with attenuated inflammation. Our data lend conceptual credence to the function of FoxO1 in mediating macrophage polarization-regulated osteogenesis which serves as a novel therapeutic target for periodontitis.

ET1 acts as a potential plasma biomarker and therapeutic target in deep venous thrombosis rat model.

Deep venous thrombosis (DVT) is the third leading cause of death in cardiovascular disease, following heart attacks and strokes. Early diagnosis and intervention are crucial for effective DVT therapy. We aim to investigate whether endothelin-1 (ET-1) could serve as an early diagnostic marker or a potential therapeutic target in a DVT rat model. CCK8 assay, invasion assay, and flow cytometry were used to detect the proliferation, migration and apoptosis of HUVECs, respectively. Elisa assay was used to detect ET-1 and coagulation factor VII in cell supernatant and rat?s plasma. Western blot was used to detect antioxidant signaling protein. Inferior vena cava stenosis was used to construct the DVT rat model. Lentivirus mediated overexpression of ET-1 in HUVECs impaired the cell proliferation and migration, increased cell apoptosis, inhibited the antioxidant signaling pathway proteins expression (e.g., NQO1, GCLC, Nrf-2), and upregulated coagulation factor VII. Furthermore, overexpression of ET-1 further impaired antioxidant signaling pathway protein in response to H2O2 treatment. However, lentivirus mediated ET-1 knockdown and BQ123 (an ET-1 inhibitor), showed the opposite results with ET-1 overexpression. We then established a DVT rat model by inferior vena cava stenosis. The stenosis induced early expression of ET-1 and coagulation factor VII in plasma at day 1 and restore their level at day 10. BQ123 could downregulate the coagulation factor VII to ameliorate the stenosis effects. Our findings suggest that ET-1 might serve as an early diagnostic marker for DVT rat model and a potential therapeutic target for treating DVT.

Integrated microbiome and metabolome analyses reveal the effects of low pH on intestinal health and homeostasis of crayfish (Procambarus clarkii).

Low pH (LpH) poses a significant challenge to the health, immune response, and growth of aquatic animals worldwide. Crayfish (Procambarus clarkii) is a globally farmed freshwater species with a remarkable adaptability to various environmental stressors. However, the effects of LpH stress on the microbiota and host metabolism in crayfish intestines remain poorly understood. In this study, integrated analyses of antioxidant enzyme activity, histopathological damage, 16S rRNA gene sequencing, and liquid chromatography-mass spectrometry (LC-MS) were performed to investigate the physiology, histopathology, microbiota, and metabolite changes in crayfish intestines exposed to LpH treatment. The results showed that LpH stress induced obvious changes in superoxide dismutase and catalase activities and histopathological alterations in crayfish intestines. Furthermore, 16S rRNA gene sequencing analysis revealed that exposure to LpH caused significant alterations in the diversity and composition of the crayfish intestinal microbiota at the phylum and genus levels. At the genus level, 14 genera including Bacilloplasma, Citrobacter, Shewanella, Vibrio, RsaHf231, Erysipelatoclostridium, Anaerorhabdus, Dysgonomonas, Flavobacterium, Tyzzerella, Brachymonas, Muribaculaceae, Propionivibrio, and Comamonas, exhibited significant differences in their relative abundances. The LC-MS analysis revealed 859 differentially expressed metabolites in crayfish intestines in response to LpH, including 363 and 496 upregulated and downregulated metabolites, respectively. These identified metabolites exhibited significant enrichment in 24 Kyoto Encyclopedia of Genes and Genomes pathways (p < 0.05), including seven and 17 upregulated and downregulated pathways, respectively. These pathways are mainly associated with energy and amino acid metabolism. Correlation analysis revealed a strong correlation between the metabolites and intestinal microbiota of crayfish during LpH treatment. These findings suggest that LpH may induce significant oxidative stress, intestinal tissue damage, disruption of intestinal microbiota homeostasis, and alterations in the metabolism in crayfish. These findings provide valuable insights into how the microbial and metabolic processes of crayfish intestines respond to LpH stress.

Genomic characterization of a novel cytorhabdovirus infecting Ixeris denticulata in China.

Ixeris denticulata is a perennial herbal plant with important medical and economic value. In this study, a novel rhabdovirus from I. denticulata with leaf curling and mottle symptoms was identified through next-generation sequencing and molecular cloning approaches. Based on the host species and properties of this virus, it was tentatively named "Ixeris denticulata-associated rhabdovirus" (IdaRV). IdaRV has a negative-sense RNA genome that is 12,705 nucleotides in length and has five open reading frames (ORFs) in the order 3'-nucleoprotein -phosphoprotein -movement protein -matrix protein -large RNA-dependent RNA polymerase-5'. Pairwise sequence comparisons showed that IdaRV had 42.2-53.0% sequence identity to members of the genera Cytorhabdovirus, Varicosavirus, Betanucleorhabdovirus, Gammanucleorhabdovirus, Dichorhavirus, and Alphanucleorhabdovirus in the subfamily Betarhabdovirinae. BLASTp searches indicated that putative products of ORF1, ORF2, ORF3, ORF4, and ORF5 of IdaRV are most closely related to those of rudbeckia virus 1 (RudV1, GenBank accession number ON185810), with 32.1%, 21.3%, 52.4%, 37.6%, and 57.1% amino acid sequence identity, respectively, at the protein level. Phylogenetic analysis showed that IdaRV forms a smaller branch with RudV1, which belongs to the genus Cytorhabdovirus. These results establish IdaRV as a novel rhabdovirus in the genus Cytorhabdovirus of the family Rhabdoviridae.

Polylactic acid microplastics have stronger positive effects on the qualitative traits of rice (Oryza sativa L.) than polyethylene microplastics: Evidence from a simulated field experiment.

Soil pollution by microplastics (MPs) from different types of agricultural films has received substantial attention due to its potential effects on crop quality. To date, the effects of different types of MPs on rice grain quality and their underlying molecular mechanisms have not been clarified. In this study, we examined the effects of polyethylene MPs (PE-MPs) and biodegradable polylactic acid MPs (PLA-MPs) on rice grain quality at the environmental level (0.5 %) and evaluated the molecular mechanism through transcriptome analysis. PE- and PLA-MPs increased the number of rice grains per plant by 19.83 % and 24.66 %, respectively, and decreased the rice empty-shell rate by 55.89 % and 26.53 %, respectively. However, PLA-MPs increased the 1000-seed weight by 11.37 %, whereas PE-MPs had no obvious impact in this respect. Furthermore, MP exposure, especially that of PE-MPs, affected the content of mineral elements, fatty acids, and amino acids of rice grains by disturbing the expression of genes related to these functions and metabolism. Our findings provide insights into the response of rice grains to the stress caused by different MPs.

Identification and pathogenicity of Fusarium spp. associated with tea wilt in Zhejiang Province, China.

BACKGROUND: Tea is one of the most widely consumed beverages in the world, with significant economic and cultural value. However, tea production faces many challenges due to various biotic and abiotic stresses, among which fungal diseases are particularly devastating. RESULTS: To understand the identity and pathogenicity of isolates recovered from tea plants with symptoms of wilt, phylogenetic analyses and pathogenicity assays were conducted. Isolates were characterized to the species level by sequencing the ITS, tef-1α, tub2 and rpb2 sequences and morphology. Four Fusarium species were identified: Fusarium fujikuroi, Fusarium solani, Fusarium oxysporum, and Fusarium concentricum. The pathogenicity of the Fusarium isolates was evaluated on 1-year-old tea plants, whereby F. fujikuroi OS3 and OS4 strains were found to be the most virulent on tea. CONCLUSIONS: To the best of our knowledge, this is the first report of tea rot caused by F. fujikuroi in the world. This provides the foundation for the identification and control of wilt disease in tea plants.

FoxO1 knockdown inhibits RANKL-induced osteoclastogenesis by blocking NLRP3 inflammasome activation.

OBJECTIVES: This study aimed to elucidate the connection between osteoclastic forkhead transcription factor O1 (FoxO1) and periodontitis and explore the underlying mechanism by which FoxO1 knockdown regulates osteoclast formation. MATERIALS AND METHODS: A conventional ligature-induced periodontitis model was constructed to reveal the alterations in the proportion of osteoclastic FoxO1 in periodontitis via immunofluorescence staining. Additionally, RNA sequencing (RNA-seq) was performed to explore the underlying mechanisms of FoxO1 knockdown-mediated osteoclastogenesis, followed by western blotting, quantitative polymerase chain reaction, and enzyme-linked immunosorbent assay. RESULTS: FoxO1+ osteoclasts were enriched in the alveolar bone in experimental periodontitis. Moreover, FoxO1 knockdown led to impaired osteoclastogenesis with low expression of osteoclast differentiation-related genes, accompanied by an insufficient osteoclast maturation phenotype. Mechanistically, RNA-seq revealed that the nuclear factor kappa B (NF-κB) and nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome signaling pathways were inhibited in FoxO1-knockdown osteoclasts. Consistent with this, MCC950, an effective inhibitor of the NLRP3 inflammasome, substantially attenuated osteoclast formation. CONCLUSIONS: FoxO1 knockdown contributed to the inhibition of osteoclastogenesis by effectively suppressing NF-κB signaling and NLRP3 inflammasome activation. This prospective study reveals the role of FoxO1 in mediating osteoclastogenesis and provides a viable therapeutic target for periodontitis treatment.

Comparative Transcriptomic Analysis of Largemouth Bass (Micropterus salmoides) Livers Reveals Response Mechanisms to High Temperatures.

High temperatures are considered one of the most significant limitations to subtropical fishery production. Largemouth bass (Micropterus salmoides) is an economically important freshwater species grown in subtropical areas, which are extremely sensitive to heat stress (HS). However, comprehensive transcriptomic data for the livers of largemouth bass in response to HS are still lacking. In this study, a comparative transcriptomic analysis was performed to investigate the gene expression profiles of the livers of largemouth bass under HS treatment. As a result, 6114 significantly differentially expressed genes (DEGs), which included 2645 up-regulated and 3469 down-regulated genes, were identified in response to HS. Bioinformatics analyses demonstrated that the 'ECM-receptor interaction' pathway was one of the most dramatically changed pathways in response to HS, and eight DEGs assigned to this pathway were taken as hub genes. Furthermore, the expression of these eight hub genes was determined by quantitative reverse transcription PCR, and all of them showed a significant change at the transcriptional level, suggesting a crucial role of the 'ECM-receptor interaction' pathway in the response of largemouth bass to HS. These findings may improve our understanding of the molecular mechanisms underlying the response of largemouth bass to HS.

Artesunate ameliorates ligature-induced periodontitis by attenuating NLRP3 inflammasome-mediated osteoclastogenesis and enhancing osteogenic differentiation.

Periodontitis, arguably the greatest common infective chronic inflammatory disease, is characterized by an imbalance of the host immune system and excessive osteoclastogenesis activity with severe alveolar bone loss. Nevertheless, in consideration of the harmful effects of repeated treatment, more sensible intervention drugs for periodontitis need to be developed. Artesunate (ART), derived from Artemisia annua L., has shown remarkable pharmacokinetic and clinical value, as well as anti-inflammatory and immunomodulatory effects in various immune and chronic diseases due to its endoperoxide group. However, the role of ART in mediating periodontitis-induced alveolar bone resorption has not been examined. In this study, ART treatment effectively ameliorated ligature-induced periodontitis via attenuating osteoclast formation in a dose-dependent manner. Mechanistically, RNA-seq revealed that ART dramatically reduced the enrichment of NLRP3 inflammasome-related genes. Concordant with our study, MCC950, a specific inhibitor of NLRP3 inflammasome, also greatly restrained osteoclastogenesis, suggesting that ART suppressed osteoclast formation by blocking NLRP3 inflammasome activation. In addition to regulating osteoclastogenesis, ART significantly enhanced osteogenic differentiation by alleviating the expression of cytokines in inflammatory conditions. Our data shed light on the probably potential mechanism of ART treatment for the intervention of periodontitis.

N-terminal acetylation of the ßC1 protein encoded by the betasatellite of tomato yellow leaf curl China virus is critical for its viral pathogenicity.

N-terminal acetylation (N-acetylation) is one of the most common protein modifications and plays crucial roles in viability and stress responses in animals and plants. However, very little is known about N-acetylation of viral proteins. Here, we identified the Thr residue at position 2 (Thr-2) in the ßC1 protein encoded by the betasatellite of tomato yellow leaf curl China virus (TYLCCNB-ßC1) as a novel N-acetylation site. Furthermore, the effects of TYLCCNB-ßC1 N-acetylation on its function as a pathogenicity factor were determined via N-acetylation mutants in Nicotiana benthamiana plants. We found that N-acetylation of TYLCCNB-ßC1 is critical for its self-interaction in the nucleus and viral pathogenesis, and that removal of N-acetylation of TYLCCNB-ßC1 attenuated tomato yellow leaf curl China virus-induced symptoms and led to accelerated degradation of TYLCCNB-ßC1 through the ubiquitin-proteasome system. Our data reveal a protective effect of N-acetylation of TYLCCNB-ßC1 on its pathogenesis and demonstrate an antagonistic crosstalk between N-acetylation and ubiquitination in this geminiviral protein.

Immunosenescence and inflammaging: Conspiracies against alveolar bone turnover.

OBJECTIVE: Inflammaging and immunosenescence are characteristics of senescent immune system alterations. This review provides insights into inflammaging and immunosenescence in periodontitis and focuses on the innerlink of inflammaging and immunosenescence in alveolar bone turnover from a perspective of cell-cell interaction. METHODS: This review is conducted by a narrative approach to discuss the effect of inflammaging and immunosenescence in aging-related alveolar bone loss. A comprehensive literature research in PubMed and Google was applied to identify reports in English. RESULTS: Inflammaging is concerned with abnormal M1 polarization and increasing circulating inflammatory cytokines, while immunosenescence involves reduced infection and vaccine responses, depressed antimicrobial function, and infiltration of aged B cells and memory T cells. TLR-mediated inflammaging and altered adaptive immunity significantly affect alveolar bone turnover and aggravate aging-related alveolar bone loss. Besides, energy consumption also plays a vital role in aged immune and skeletal system of periodontitis. CONCLUSIONS: Senescent immune system exerts a significant function in aging-related alveolar bone loss. Inflammaging and immunosenescence interact functionally and mechanistically, which affects alveolar bone turnover. Therefore, further clinical treatment strategies targeting alveolar bone loss could be based on the specific molecular mechanism connecting inflammaging, immunosenescence, and alveolar bone turnover.

The RING-Finger Protein NbRFP1 Contributes to Regulating the Host Hypersensitive Response Induced by Oat Dwarf Virus RepA.

Our previous study identified that the RepA protein encoded by the oat dwarf virus (ODV) was responsible for inducing a strong hypersensitive response (HR) during the virus infection in non-host tobacco plants. However, little was known about the molecular mechanism of the RepA-elicited HR. Here, a RING-finger protein, which is described as NbRFP1 and is mainly located in the cytoplasm and nucleus in Nicotiana benthamiana cells, was confirmed to interact with RepA. In addition, the accumulation level of NbRFP1 in N. benthamiana leaves was enhanced by either ODV infection or by only RepA expression. The knockdown of NbRFP1 by a TRV-mediated virus-induced gene silencing markedly delayed the ODV or RepA-elicited HR. By contrast, the overexpression of NbRFP1 in N. benthamiana conferred enhanced resistance to ODV infection and promoted RepA-induced HR. Further mutation analysis showed that a RING-finger domain located in NbRFP1 plays important roles in modulating RepA-induced HR, as well as in mediating the interaction between NbRFP1 and RepA.

Multi-scenario simulation of China's dynamic relationship between water-land resources allocation and cultivated land use based on shared socioeconomic pathways.

Rapid urban expansion, population growth, and limited cultivated land in China necessitate rethinking the path to sustainable management of cultivated land. Understanding the long-term dynamic relationship between water-land resource endowment and cultivated land use contributes to effective management and use of cultivated land. However, few studies have systematically documented this relationship, especially for future trends. Accordingly, we modified water-land resource matching (WLRM) using a more refined grid-scale and assessed cultivated land use efficiency (CLUE), then deployed spatial panel regression models to quantify historical changes. We subsequently simulated future trends under three Shared Socioeconomic Pathways scenarios. The results showed that the relationship assumed an N-shaped curve in nation, while the curve followed a down-up-down pattern in economically less developed regions, largely because of structural transformations of production factors. Under three development scenarios, the stage-specific characteristics of production factors were pronounced, and the dynamic relationship varied across regions.

Identification and Molecular Characterization of a Novel Carlavirus Infecting Chrysanthemum morifolium in China.

Chrysanthemum (Chrysanthemum morifolium) is an important ornamental and medicinal plant suffering from many viruses and viroids worldwide. In this study, a new carlavirus, tentatively named Chinese isolate of Carya illinoinensis carlavirus 1 (CiCV1-CN), was identified from chrysanthemum plants in Zhejiang Province, China. The genome sequence of CiCV1-CN was 8795 nucleotides (nt) in length, with a 68-nt 5'-untranslated region (UTR) and a 76-nt 3'-UTR, which contained six predicted open reading frames (ORFs) that encode six corresponding proteins of various sizes. Phylogenetic analyses based on full-length genome and coat protein sequences revealed that CiCV1-CN is in an evolutionary branch with chrysanthemum virus R (CVR) in the Carlavirus genus. Pairwise sequence identity analysis showed that, except for CiCV1, CiCV1-CN has the highest whole-genome sequence identity of 71.3% to CVR-X6. At the amino acid level, the highest identities of predicted proteins encoded by the ORF1, ORF2, ORF3, ORF4, ORF5, and ORF6 of CiCV1-CN were 77.1% in the CVR-X21 ORF1, 80.3% in the CVR-X13 ORF2, 74.8% in the CVR-X21 ORF3, 60.9% in the CVR-BJ ORF4, 90.2% in the CVR-X6 and CVR-TX ORF5s, and 79.4% in the CVR-X21 ORF6. Furthermore, we also found a transient expression of the cysteine-rich protein (CRP) encoded by the ORF6 of CiCV1-CN in Nicotiana benthamiana plants using a potato virus X-based vector, which can result in a downward leaf curl and hypersensitive cell death over the time course. These results demonstrated that CiCV1-CN is a pathogenic virus and C. morifolium is a natural host of CiCV1.

Gut microbiota of two invasive fishes respond differently to temperature.

Temperature variation structures the composition and diversity of gut microbiomes in ectothermic animals, key regulators of host physiology, with potential benefit to host or lead to converse results (i.e., negative). So, the significance of either effect may largely depend on the length of time exposed to extreme temperatures and how rapidly the gut microbiota can be altered by change in temperature. However, the temporal effects of temperature on gut microbiota have rarely been clarified. To understand this issue, we exposed two juvenile fishes (Cyprinus carpio and Micropterus salmoides), which both ranked among the 100 worst invasive alien species in the world, to increased environmental temperature and sampled of the gut microbiota at multiple time points after exposure so as to determine when differences in these communities become detectable. Further, how temperature affects the composition and function of microbiota was examined by comparing predicted metagenomic profiles of gut microbiota between treatment groups at the final time point of the experiment. The gut microbiota of C. carpio was more plastic than those of M. salmoides. Specifically, communities of C. carpio were greatly altered by increased temperature within 1 week, while communities of M. salmoides exhibit no significant changes. Further, we identified 10 predicted bacterial functional pathways in C. carpio that were temperature-dependent, while none functional pathways in M. salmoides was found to be temperature-dependent. Thus, the gut microbiota of C. carpio was more sensitive to temperature changes and their functional pathways were significantly changed after temperature treatment. These results showed the gut microbiota of the two invasive fishes differ in response to temperature change, which may indicate that they differ in colonization modes. Broadly, we have confirmed that the increased short-term fluctuations in temperatures are always expected to alter the gut microbiota of ectothermic vertebrates when facing global climate change.

Integrated comparative transcriptome and weighted gene co-expression network analysis provide valuable insights into the response mechanisms of crayfish (Procambarus clarkii) to copper stress.

One of the significant limitations of aquaculture worldwide is the prevalence of divalent copper (Cu). Crayfish (Procambarus clarkii) are economically important freshwater species adapted to a variety of environmental stimuli, including heavy metal stresses; however, large-scale transcriptomic data of the hepatopancreas of crayfish in response to Cu stress are still scarce. Here, integrated comparative transcriptome and weighted gene co-expression network analyses were initially applied to investigate gene expression profiles of the hepatopancreas of crayfish subjected to Cu stress for different periods. As a result, 4662 significant differentially expressed genes (DEGs) were identified following Cu stress. Bioinformatics analyses revealed that the "focal adhesion" pathway was one of the most significantly upregulated response pathways following Cu stress, and seven DEGs mapped to this pathway were identified as hub genes. Furthermore, the seven hub genes were examined by quantitative PCR, and each was found to have a substantial increase in transcript abundance, suggesting a critical role of the "focal adhesion" pathway in the response of crayfish to Cu stress. Our transcriptomic data can be a good resource for the functional transcriptomics of crayfish, and these results may provide valuable insights into the molecular response mechanisms underlying crayfish to Cu stress.

Ubiquitin-specific proteases: Vital regulatory molecules in bone and bone-related diseases.

Stabilization of bone structure and function involves multiple cell-to-cell and molecular interactions, in which the regulatory functions of post-translational modifications such as ubiquitination and deubiquitination shouldn't be underestimated. As the largest family of deubiquitinating enzymes, the ubiquitin-specific proteases (USPs) participate in the development of bone homeostasis and bone-related diseases through multiple classical osteogenic and osteolytic signaling pathways, such as BMP/TGF-ß pathway, NF-κB/p65 pathway, EGFR-MAPK pathway and Wnt/ß-catenin pathway. Meanwhile, USPs may also broadly regulate regulate hormone expression level, cell proliferation and differentiation, and may further influence bone homeostasis from gene fusion and nuclear translocation of transcription factors. The number of patients with bone-related diseases is currently enormous, making exploration of their pathogenesis and targeted therapy a hot topic. Pathological increases in the levels of inflammatory mediators such as IL-1ß and TNF-α lead to inflammatory bone diseases such as osteoarthritis, rheumatoid arthritis and periodontitis. While impaired body metabolism greatly increases the probability of osteoporosis. Abnormal physiological activity of bone-associated cells results in a variety of bone tumors. The regulatory role of USPs in bone-related disease has received particular attention from academics in recent studies. In this review, we focuse on the roles and mechanisms of USPs in bone homeostasis and bone-related diseases, with the expectation of informing targeted therapies in the clinic.

Genome-wide identification and expression analysis of wall-associated kinase (WAK) and WAK-like kinase gene family in response to tomato yellow leaf curl virus infection in Nicotiana benthamiana.

BACKGROUND: Tomato yellow leaf curl virus (TYLCV) is a major monopartite virus in the family Geminiviridae and has caused severe yield losses in tomato and tobacco planting areas worldwide. Wall-associated kinases (WAKs) and WAK-like kinases (WAKLs) are a subfamily of the receptor-like kinase family implicated in cell wall signaling and transmitting extracellular signals to the cytoplasm, thereby regulating plant growth and development and resistance to abiotic and biotic stresses. Recently, many studies on WAK/WAKL family genes have been performed in various plants under different stresses; however, identification and functional survey of the WAK/WAKL gene family of Nicotiana benthamiana have not yet been performed, even though its genome has been sequenced for several years. Therefore, in this study, we aimed to identify the WAK/WAKL gene family in N. benthamiana and explore their possible functions in response to TYLCV infection. RESULTS: Thirty-eight putative WAK/WAKL genes were identified and named according to their locations in N. benthamiana. Phylogenetic analysis showed that NbWAK/WAKLs are clustered into five groups. The protein motifs and gene structure compositions of NbWAK/WAKLs appear to be highly conserved among the phylogenetic groups. Numerous cis-acting elements involved in phytohormone and/or stress responses were detected in the promoter regions of NbWAK/WAKLs. Moreover, gene expression analysis revealed that most of the NbWAK/WAKLs are expressed in at least one of the examined tissues, suggesting their possible roles in regulating the growth and development of plants. Virus-induced gene silencing and quantitative PCR analyses demonstrated that NbWAK/WAKLs are implicated in regulating the response of N. benthamiana to TYLCV, ten of which were dramatically upregulated in locally or systemically infected leaves of N. benthamiana following TYLCV infection. CONCLUSIONS: Our study lays an essential base for the further exploration of the potential functions of NbWAK/WAKLs in plant growth and development and response to viral infections in N. benthamiana.

Potential ecological risk and zoning control strategies for heavy metals in soils surrounding core water sources: A case study from Danjiangkou Reservoir, China.

Heavy metals in soils can migrate into the food chain and affect human health. In particular, they can be released into water supplies through interactions between soils and water. It is therefore important to study the concentrations of heavy metals in soils surrounding sources of drinking water, but there is a lack of research in this area. A total of 7656 topsoil samples surrounding the core water source of Danjiangkou Reservoir in China were collected and analyzed for As, Hg and Pb. Moran's I index and semivariograms were used to analyze the spatial correlation and variation of these heavy metals. The potential ecological risk index was used to evaluate heavy metal pollution. Fifteen natural and human factors were selected to explore the sources of heavy metal pollution using the GeoDetector model. The positive matrix factorization (PMF) model verified the reasonableness of the main factors identified by the GeoDetector model and further quantified two main sources of soil heavy metals. As, Hg and Pb were enriched to varying degrees in the soils. The potential ecological risk of Hg in soils was the most serious, with 24.67% of the area at high or very high risk. As and Pb both had a low potential ecological risk. The results of GeoDetector model and PMF model showed that the contributions of factor 1 (fertilizer application and automobile exhaust emissions) and factor 2(industrial waste) of soil heavy metal pollution were 49.8% and 50.2%, respectively. At last, the zoning control strategies were proposed in order to provide scientific reference for the management of soil heavy metal pollution.