Comprehensive genomic analysis of Burkholderia arboris PN-1 reveals its biocontrol potential against Fusarium solani-induced root rot in Panax notoginseng.

Panax notoginseng (Burkill) F.H. Chen, a valuable traditional Chinese medicine, faces significant yield and quality challenges stemming from root rot primarily caused by Fusarium solani. Burkholderia arboris PN-1, isolated from the rhizosphere soil of P. notoginseng, demonstrated a remarkable ability to inhibit the growth of F. solani. This study integrates phenotypic, phylogenetic, and genomic analyses to enhance our understanding of the biocontrol mechanisms employed by B. arboris PN-1. Phenotype analysis reveals that B. arboris PN-1 effectively suppresses P. notoginseng root rot both in vitro and in vivo. The genome of B. arboris PN-1 comprises three circular chromosomes (contig 1: 3,651,544 bp, contig 2: 1,355,460 bp, and contig 3: 3,471,056 bp), with a 66.81% GC content, housing 7,550 protein-coding genes. Notably, no plasmids were detected. Phylogenetic analysis places PN-1 in close relation to B. arboris AU14372, B. arboris LMG24066, and B. arboris MEC_B345. Average nucleotide identity (ANI) values confirm the PN-1 classification as B. arboris. Comparative analysis with seven other B. arboris strains identified 4,628 core genes in B. arboris PN-1. The pan-genome of B. arboris appears open but may approach closure. Whole-genome sequencing revealed 265 carbohydrate-active enzymes and identified 9 gene clusters encoding secondary metabolites. This comprehensive investigation enhances our understanding of B. arboris genomes, paving the way for their potential as effective biocontrol agents against fungal plant pathogens in the future.

Regulatory role of miR-129 and miR-384-5p on apoptosis induced by oxygen and glucose deprivation in PC12 cell.

This study aimed to establish the role of miR-129 and miR-384-5p in cerebral ischemia-induced apoptosis. Using PC12 cells transfected with miR-129 or miR-384-5p mimics or inhibitors, oxygen glucose deprivation (OGD) conditions were applied for 4 h to simulate transient cerebral ischemia. Apoptotic phenotypes were assessed via lactate dehydrogenase (LDH) assay, MTT cell metabolism assay, and fluorescence-activated cell sorting (FACS). The effect of miR overexpression and inhibition was evaluated by protein and mRNA detection of bcl-2 and caspase-3, critical apoptosis factors. Finally, the direct relationship of miR-129 and bcl-2 and miR-384-5p and caspase-3 was measured by luciferase reporter assay. The overexpression of miR-384-5p and miR-129 deficiency significantly enhanced cell viability, reduced LDH release, and inhibited apoptosis. By contrast, overexpression of miR-129 and miR-384-5p deficiency aggravated hypoxia-induced apoptosis and cell injury. miR-129 overexpression significantly reduced mRNA and protein levels of bcl-2 and miR-129 inhibition significantly increased mRNA and protein levels of bcl-2 in hypoxic cells.miR-384-5p overexpression significantly reduced protein levels of caspase-3 while miR-384-5p deficiency significantly increased protein levels of caspase-3. However, no changes were observed in caspase-3 mRNA in either transfection paradigm. Finally, luciferase reporter assay confirmed caspase-3 to be a direct target of miR-384-5p; however, no binding activity was detected between bcl-2 and miR-129.Transient cerebral ischemia induces differential expression of miR-129 and miR-384-5p which influences apoptosis by regulating apoptotic factors caspase-3 and bcl-2, thereby participating in the pathological mechanism of cerebral ischemia, and becoming potential targets for the treatment of ischemic cerebral injury in the future.

Nocardia panacis sp. nov., a novel actinomycete with antiphytopathogen activity isolated from the rhizosphere of Panax notoginseng.

Strain YIM PH21724T was isolated from the rhizosphere of Panax notoginseng. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strain exhibits close phylogenetic relatedness to Nocardia kroppenstedtii N1286T (97.70%), Nocardia farcinica NCTC 11134T (97.67%) and Nocardia puris DSM 44599T (97.40%). The menaquinones were identified as MK-9 (H4), MK-8 (H4, ω-cyclo) and MK-8 (H4), and the major fatty acids (> 10%) were identified as C16:0, C18:1 ω9c and C18:0 10-methyl. The polar lipids were found to be composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides and an unidentified lipid. The G + C content of the genomic DNA was determined to be 67.01 mol%. The phenotypic, chemotaxonomic, phylogenetic and genomic results clearly show strain YIM PH21724T should be classified in the genus Nocardia and represents a novel species, for which the name Nocardia panacis sp. nov. is proposed. The type strain is YIM PH21724T (= DSM 105904T = KCTC 49030T = CCTCC AA 2017043T).

Gracilibacillus eburneus sp.nov., a moderately halophilic bacterium isolated from Xinjiang province, China.

A novel Gram-staining positive, moderately halophilic, endospore-forming, motile, rod-shaped and strictly aerobic strain, designated YIM 93565T, was isolated from a salt lake in Xinjiang province of China and subjected to a polyphasic taxonomic study. Strain YIM 93565T grew in the range of pH 6.0-9.0 (optimum pH 7.0), 10-45 °C (optimum 35-40 °C) and at salinities of 2-24% (w/v) NaCl (optimum 7-10%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YIM 93565T clustered with members of the genera Gracilibacillus and form a clade with Gracilibacillus bigeumensis KCTC 13130T (95.6% similarity) and Gracilibacillus halophilus DSM 17856T (94.9%), which was well separated from others. The DNA G + C content of this novel strain was 36.8 mol%. The major fatty acids were anteiso-C15:0, iso-C15:0, C16:0 and anteiso-C17:0 and its polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, one unidentified glycolipid and two unidentified phospholipids. The predominant menaquinone was MK-7. The cell-wall peptidoglycan was based on meso-diaminopimelic acid. Based on the results of phylogenetic, physiological and chemotaxonomic comparative analyses, the isolate is assigned to a novel species of the genus Gracilibacillus, for which the name Gracilibacillus eburneus sp. nov. is proposed, with the type strain YIM 93565T (= DSM 23710T = CCTCC AB 2013249T).

Expression, purification, and evaluation of in vivo anti-fibrotic activity for soluble truncated TGF-ß receptor II as a cleavable His-SUMO fusion protein.

Excessive production of transforming growth factor-ß1 (TGF-ß1) and its binding to transforming growth factor-ß receptor type II (TGF-ßRII) promotes fibrosis by activation of the TGF-ß1-mediated signaling pathway. Thus, the truncated extracellular domain of TGF-ßRII (tTßRII) is a promising anti-fibrotic candidate, as it lacks the signal transduction domain. In this work, the native N-terminal tTßRII was prepared as a His-SUMO fusion protein (termed His-SUMO-tTßRII) in Escherichia coli strain BL21 (DE3). His-SUMO-tTßRII was expressed as a soluble protein under optimal conditions (6 h of induction with 0.5 mM IPTG at 37 °C). His-SUMO-tTßRII was purified by Ni-NTA resin chromatography, and then cleaved with SUMO protease to release native tTßRII, which was re-purified using a Ni-NTA column. Approximately 12 mg of native tTßRII was obtained from a one liter fermentation culture with no less than 95% purity. In vivo studies demonstrated that tTßRII prevented CCl4-induced liver fibrosis, as evidenced by the inhibition of fibrosis-related Col I and α-SMA protein expression in C57BL/6 mice. In addition, tTßRII downregulated phosphorylation of SMAD2/3, which partly repressed TGF-ß1-mediated signaling. These data indicate that the His-SUMO expression system is an efficient approach for preparing native tTßRII that possesses anti-liver fibrotic activity, allowing for the large-scale production of tTßRII, which potentially could serve as an anti-fibrotic candidate for treatment of TGF-ß1-related diseases.

Haplotype-resolved genome assembly of the diploid Rosa chinensis provides insight into the mechanisms underlying key ornamental traits.

Roses are consistently ranked at the forefront in cut flower production. Increasing demands of market and changing climate conditions have resulted in the need to further improve the diversity and quality of traits. However, frequent hybridization leads to highly heterozygous nature, including the allelic variants. Therefore, the absence of comprehensive genomic information leads to them making it challenging to molecular breeding. Here, two haplotype-resolved chromosome genomes for Rosa chinensis 'Chilong Hanzhu' (2n = 14) which is high heterozygous diploid old Chinese rose are generated. An amount of genetic variation (1,605,616 SNPs, 209,575 indels) is identified. 13,971 allelic genes show differential expression patterns between two haplotypes. Importantly, these differences hold valuable insights into regulatory mechanisms of traits. RcMYB114b can influence cyanidin-3-glucoside accumulation and the allelic variation in its promoter leads to differences in promoter activity, which as a factor control petal color. Moreover, gene family expansion may contribute to the abundance of terpenes in floral scents. Additionally, RcANT1, RcDA1, RcAG1 and RcSVP1 genes are involved in regulation of petal number and size under heat stress treatment. This study provides a foundation for molecular breeding to improve important characteristics of roses.

Research Note: Real-time fluorescence-based recombinase-aided amplification for rapid detection of Mycoplasma synoviae.

Mycoplasma synoviae (MS) is an essential pathogenic mycoplasma in poultry worldwide, posing a serious threat to the poultry industry's health. Timely detection is imperative for early diagnosis, prevention, and control of MS infection. Current laboratory methods for MS detection are generally complicated, time-consuming, and require sophisticated equipment. Therefore, a simple and rapid method is urgently needed. This study developed a novel real-time fluorescence-based recombinase-aided amplification (RF-RAA) technique for detecting MS nucleic acids, enabling target gene amplification within 20 min at 39°C. The RF-RAA outcomes are interpretable in 2 modalities: real-time fluorescence monitoring employing a temperature-controlled fluorescence detector or direct visual inspection facilitated by a portable blue light transilluminator. This method exhibits robust specificity, demonstrating no cross-reactivity with various common poultry pathogens, and achieves high sensitivity, detecting as low as 10 copies/µL for the standard plasmid. Seventy-one clinical samples of chicken throat swabs were detected by RF-RAA and real-time fluorescence quantitative polymerase chain reaction (qPCR) methods. The diagnostic coincidence rates of qPCR with RF-RAA (fluorescence monitoring) and RF-RAA (visual observation) were determined to be 100% and 97.2% (69/71), respectively. In conclusion, the RF-RAA method developed in this study provides a rapid and visually observable approach for MS detection, offering a novel technique to diagnosing MS infection, especially in resource-limited settings.

Heating tumors with tumor cell-derived nanoparticles to enhance chemoimmunotherapy for colorectal cancer.

Aim: To investigate the mechanism of doxorubicin (DOX)-induced immunogenic cell death (ICD) and to improve immunotherapy efficacy. Materials & methods: In this study, hybrid vesicles containing DOX (HV-DOX) were prepared by thin-film hydration with extrusion, and the formulated nanoparticles were characterized physically. Furthermore, in vitro experiments and animal models were used to investigate the efficacy and new mechanisms of chemotherapy combined with immunotherapy. Results: DOX improved tumor immunogenicity by alkalinizing lysosomes, inhibiting tumor cell autophagy and inducing ICD. HVs could activate dendritic cell maturation, synergistically enhancing chemotherapeutic immunity. Conclusion: The mechanism of DOX-induced ICD was explored, and antitumor immunity was synergistically activated by HV-DOX to improve chemotherapeutic drug loading and provide relevant antigenic information.

Polymorphisms of ERBB2 and breast cancer risk: a meta-analysis of 26 studies involving 35,088 subjects.

BACKGROUND AND OBJECTIVES: Several epidemiologic studies have investigated the relationship between the polymorphisms of ERBB2 gene and breast cancer risk. However, the results are inconclusive. This meta-analysis aimed to assess the association between ERBB2 Ile655Val and Ala1170Pro polymorphisms and the susceptibility to breast cancer. METHODS: Twenty-six studies including 15,940 cases and 19,148 controls were analyzed in this meta-analysis. RESULTS: Overall, allele contrast (Val vs. Ile) of ERBB2 655 polymorphism produced significant results in worldwide populations (OR = 1.123, 95%CI = 1.01-1.249) and in Caucasian populations (OR = 1.149, 95%CI = 1.002-1.318). In addition, the Val/Val genotype of ERBB2 655 polymorphism was associated with an increase risk of breast cancer in African (Val/Val vs. Ile/Ile OR = 16.031 95%CI = 2.019-127.267; Val/Val vs. Ile/Val + Ile/Ile OR = 16.445 95%CI = 2.059-131.351), but not in Caucasian or Asian individuals. CONCLUSIONS: ERBB2 655 Val allele would be a risk factor for breast cancer, especially in Caucasian populations. In addition, the Val/Val genotype was a risk factor for breast cancer in African individuals. ERBB2 Ala1170Pro was not associated with breast cancer susceptibility.

Tenuibacillus halotolerans sp. nov., a novel bacterium isolated from a soil sample from a salt lake in Xinjiang, China and emended description of the genus Tenuibacillus.

A Gram-positive, moderately halotolerant, rod-shaped bacterium, designated YIM 94025(T), was isolated from a soil sample from a salt lake in Xinjiang province, north-west China. Strain YIM 94025(T) was observed to grow at 25-45 °C (optimum 37 °C), 0-22 % NaCl (optimum 2-10 %) and pH 6.0-9.0 (optimum pH 8.0). Phylogenetic analyses based on 16S rRNA gene sequences revealed that the organism belongs to the genus Tenuibacillus and exhibited sequence similarity of 98.0 % to the closest type strain, Tenuibacillus multivorans AS 1.3442(T). The predominant menaquinone was found to be MK-7; the cell-wall peptidoglycan diamino acid was meso-diaminopimelic acid; the polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, an unidentified phospholipid and an unknown lipid; and the major fatty acids were found to contain iso-C(15:0), anteiso-C(15:0) and iso-C(16:0). The chemotaxonomic characteristics of strain YIM 94025(T) are consistent with those of the genus Tenuibacillus. The level of DNA-DNA relatedness value between YIM 94025(T) and T. multivorans AS 1.3442(T) was 36.6 ± 4.5 %. The G+C content of the strain YIM 94025(T) was determined to be 38.5 %. Based on the comparative analysis of physiological, biochemical and chemotaxonomic data, as well as DNA-DNA hybridization results, the isolate is considered to represent a novel species of the genus Tenuibacillus, for which the name Tenuibacillus halotolerans sp. nov., is proposed, with the type strain of YIM 94025(T) (=CCTCC AB 2012860(T) = KCTC 33046(T)).

Dual Signal-Enhanced Electrochemiluminescence Strategy Based on Functionalized Biochar for Detecting Aflatoxin B1.

Metal-organic frameworks (MOFs) are often used as carriers in the preparation of electrochemiluminescent (ECL) materials, and ECL materials stabilized in the aqueous phase can be prepared by encapsulating chromophores inside MOFs by an in situ growth method. In this study, nanocomposites MIL-88B(Fe)-NH2@Ru(py)32+ with excellent ECL response were prepared by encapsulating Tris(2,2'-bipyridine)ruthenium dichloride (Ru(py)32+) inside MIL-88B(Fe)-NH2 using the one-step hydrothermal method. MIL-88B(Fe)-NH2 possesses abundant amino groups, which can accelerate the catalytic activation process of K2S2O8, and its abundant pores are also conducive to the enhancement of the transmission rate of co-reactant agents, ions, and electrons, which effectively improves the ECL efficiency. In order to obtain more excellent ECL signals, we prepared aminated biochar (NH2-biochar) using Pu-erh tea dregs as precursor and loaded gold nanoparticles (Au NPs) on its surface as substrate material for modified electrodes. Both NH2-biochar and Au NPs can also be used as a co-reactant promoter to catalyze the activation process of co-reactant K2S2O8. Therefore, a sandwich-type ECL immunosensor was prepared based on a dual signal-enhanced strategy for the highly sensitive and selective detection of aflatoxin B1 (AFB1). Under the optimal experimental conditions, the sensitive detection of AFB1 was achieved in the range of 1 pg·mL-1~100 ng·mL-1 with a detection limit of 209 fg·mL-1. The proposed dual signal-enhanced ECL immunosensor can provide a simple, convenient, and efficient method for the sensitive detection of AFB1 in food and agricultural products.

Treatment with Mesenchymal Stem Cell-Derived Nanovesicle-Containing Gelatin Methacryloyl Hydrogels Alleviates Osteoarthritis by Modulating Chondrogenesis and Macrophage Polarization.

Osteoarthritis is a degenerative disorder that can severely affect joints, and new treatment strategies are urgently needed. Administration of mesenchymal stem cell (MSC)-derived exosomes is a promising therapeutic strategy in osteoarthritis treatment. However, the poor yield of exosomes is an obstacle to the use of this modality in the clinic. Herein, a promising strategy is developed to fabricate high-yield exosome-mimicking MSC-derived nanovesicles (MSC-NVs) with enhanced regenerative and anti-inflammatory capabilities. MSC-NVs are prepared using an extrusion approach and are found to increase chondrocyte and human bone marrow MSC differentiation, proliferation, and migration, in addition to inducing M2 macrophage polarization. Furthermore, gelatin methacryloyl (GelMA) hydrogels loaded with MSC-NVs (GelMA-NVs) are formulated, which exhibit sustained release of MSC-NVs and are shown to be biocompatible with excellent mechanical properties. In a mouse osteoarthritis model constructed by surgical destabilization of the medial meniscus (DMM), GelMA-NVs effectively ameliorate osteoarthritis severity, reduce the secretion of catabolic factors, and enhance matrix synthesis. Furthermore, GelMA-NVs induce M2 macrophage polarization and inflammatory response inhibition in vivo. The findings demonstrate that GelMA-NVs hold promise for osteoarthritis treatment through modulation of chondrogenesis and macrophage polarization.

Comprehensive Genome-Wide Analysis of Histone Acetylation Genes in Roses and Expression Analyses in Response to Heat Stress.

Roses have high economic values as garden plants and for cut-flower and cosmetics industries. The growth and development of rose plants is affected by exposure to high temperature. Histone acetylation plays an important role in plant development and responses to various stresses. It is a dynamic and reversible process mediated by histone deacetylases (HDAC) and histone acetyltransferases (HAT). However, information on HDAC and HAT genes of roses is scarce. Here, 23 HDAC genes and 10 HAT genes were identified in the Rosa chinensis 'Old Blush' genome. Their gene structures, conserved motifs, physicochemical properties, phylogeny, and synteny were assessed. Analyses of the expression of HDAC and HAT genes using available RNAseq data showed that these genes exhibit different expression patterns in different organs of the three analyzed rose cultivars. After heat stress, while the expression of most HDAC genes tend to be down-regulated, that of HAT genes was up-regulated when rose plants were grown at high-temperature conditions. These data suggest that rose likely respond to high-temperature exposure via modification in histone acetylation, and, thus, paves the way to more studies in order to elucidate in roses the molecular mechanisms underlying rose plants development and flowering.

Construction of a Prognostic Model for Hypoxia-Related LncRNAs and Prediction of the Immune Landscape in the Digestive System Pan-Cancer.

Digestive system pan-cancer is a general term for digestive system tumors including colorectal carcinoma (CRC), esophageal carcinoma (ESCA), stomach adenocarcinoma (STAD), and liver hepatocellular carcinoma (LIHC). Since the anatomical location, function and metabolism are closely related, there may be similarities in development and progression of these tumors. Hypoxia is the consequence of an imbalance between oxygen demand and supply, and intracellular hypoxia is associated with malignant progression, treatment resistance, and poor prognosis in tumors. Therefore, an urgent and challenging task is to investigate the molecular mechanisms associated with hypoxia in digestive system pan-cancer for the prognosis and treatment of digestive tract tumors. In this study, we identified 18 hypoxia-related lncRNAs (HRlncRNAs) by co-expression analysis between hypoxia genes and lncRNAs from digestive system pan-cancer. Six HRlncRNAs were then obtained using lasso regression and multivariate cox analysis to construct a prognostic model. Next, the Akaike information criterion (AIC) values for 3-year receiver operating curve (ROC) were counted to determine the cut-off point and establish an optimal model to distinguish between high- or low-risk groups among patients with digestive system pan-cancer. To evaluate the stability of the prognosis model, we validated it in terms of survival outcomes, clinicopathological stage, tumor-infiltrating immune cells, immune checkpoint inhibitors (ICIs) and anticancer drugs sensitivity. The results suggested that high- risk group had a worse prognosis and a more positive association with tumor-infiltrating immune cells such as B cells, cancer-associated fibroblasts, endothelial cells, monocytes, macrophages and bone marrow dendritic cells in digestive system pan-cancer. Immune checkpoint inhibitors (ICIs) related biomarkers discovered that high-risk group was positively correlated with high expression of HAVCR2 in digestive system pan-cancer. The anticancer drugs sensitivity analysis showed that the high-risk group was associated with the lower half-inhibitory centration (IC50) of Imatinib in digestive system pan-cancer. In conclusion, the prognostic model of HRlncRNAs showed a promising clinical prediction value and may provide a useful reference for the diagnosis and treatment of the digestive system tumors.

Heparan sulfate proteoglycans-mediated targeted delivery of TGF-ß1-binding peptide to liver for improved anti-liver fibrotic activity in vitro and in vivo.

Elevated expressions of transforming growth factor ß1 (TGF-ß1) have been implicated in the pathogenesis of liver fibrosis, thus attenuating the excessive TGF-ß1's activity by TGF-ß1-binding peptide is an ideal strategy for the treatment of liver fibrosis. However, the application of small peptide as a pharmaceutical agent is obstacle due to difficult preparation and non-selective delivery. The I-plus sequences of circumsporozoite protein (CSP-I) possesses high affinity for heparan sulfate proteoglycans, which are primarily located on liver tissues. TGF-ß1-binding peptide P15 holds specific ability of binding to TGF-ß1. In this study, we describe an approach to efficiently preparing liver-targeting peptide P15-CSP-I, which is conjugation of the sequences of P15 to the N-terminus of CSP-I, from the cleavage of biological macromolecule SUMO-tagged P15-CSP-I. In vitro and ex vivo binding assay showed that P15-CSP-I specifically targeted to the hepatocytes and liver tissues. Moreover, P15-CSP-I inhibited cell proliferation, migration and invasion, and decreased fibrosis-related proteins expression in TGF-ß1-activated HSCs in vitro. Furthermore, P15-CSP-I ameliorated liver morphology and decreased the fibrosis responses in vivo. Taken together, P15-CSP-I may be a potential candidate for targeting therapy on liver fibrosis due to its high efficient preparation, specific liver-targeting potential and improved anti-liver fibrotic activity.

Biochar increases Panax notoginseng's survival under continuous cropping by improving soil properties and microbial diversity.

Replant problem is widespread in agricultural production and causes serious economic losses, which has limited sustainable cultivation of Panax notoginseng (PN), a well-known medicinal plant in Asia. Here we conducted a field experiment to investigate the effectiveness and possible mechanisms of biochar to improve its survival under continuous cropping. Biochar from tobacco stems was applied at 4 rates of 9.0, 12, 15, and 18 t/ha to a soil where PN has been continuously cultivated for 10 years. After 18 months, soil properties, 5 allelochemicals, including p-hydroxybenzoic acid, vanillic acid, syringic acid, p-coumaric acid, and ferulic acid, key pathogen Fusarium oxysporum, microbial community, and PN survival rate were investigated. Our results show that 10 years' continuous PN cropping led to soil acidification, accumulation of NH4+-N and F. oxysporum, and low PN survival rate. However, biochar increased its survival rate from 6.0% in the control to 69.5% under 15 t/ha treatment. Moreover, soil pH, available P and K, organic matter content, and microbial diversity were increased while NH4+-N and allelochemicals vanillic acid and syringic acid contents were decreased under biochar treatment (P<0.05). Soil available K increased from 177 to 283 mg·kg-1 while NH4+-N decreased from 6.73 to 4.79 mg·kg-1 under 15 t/ha treatment. Further, soil pH, available P and K, and microbial diversity (bacteria and fungi) were positively correlated with PN survival rate, however, NH4+-N content was negatively correlated (P<0.05). Our study indicates that biochar effectively increased the survival rate of Panax notoginseng under continuous cropping by improving soil properties and microbial diversity.

[Distribution of microbes and their hereditary diversity in the rhizosphere of carnation in greenhouse].

OBJECTIVE: To investigate the relationship between microbial community and the blight diseases in rhizosphere of carnation for biological control. METHODS: Bacterial strains isolated from the rhizosphere of healthy and blight carnation plants in greenhouse were replicated by morphology and 16S rRNA gene similarity, and investigated by using phylogenetic analysis based on 16S rRNA gene sequence alignments. RESULTS: Isolates belonged to 4 phyla of bacteria, 65 isolates from the samples of healthy carnation plants belonged to 9 genera and Bacillus, Streptomyces, Mortierella were the dominant bacteria. However, 33 isolates from the samples of blight carnation plants belonged to 12 genera and Stenotrophomonas, Sphingobacterium, Pseudomonas, Chryseobacterium, Amycolatopsis and Fusarium were only isolated from the sample of blight carnation plants. At least 13 isolates should represent potential novel species based on lower similarities of 16 S rRNA gene (90%-98% ). CONCLUSION: The result showed that either the percentage of the fungus in the total strains or the abundance of Bacillus groups in the total strains can be the referential targets to evaluate whether the carnation soil would be healthy for the carnational growth or lead to fusarium wilt diseases, accurately forecasting potential risks of the disease.

Bacillus subtilis strain BS06 protects soybean roots from Fusarium oxysporum infection.

Soybean, as a major oil crop, is one of the most widely planted crops in the world. Fusarium oxysporum causes soybean root rot, leading to great economic losses to soybean planting every year globally. Chemical fungicide for controlling soybean F. oxysporum diseases may cause environmental problems and has human health risks. Biological control methods avoid these shortcomings; however, few studies have focused on biocontrol of soybean diseases caused by F. oxysporum. Aiming at this problem, we obtained biocontrol bacteria against soybean F. oxysporum by plate confrontation method. The type of the strain with the highest biocontrol activity was identified by molecular biological methods, and then its biocontrol effects were verified through greenhouse experiments. One of our isolated strain named BS06 strain had the highest activity, which was identified as Bacillus subtilis. Our study showed that BS06 strain could effectively control soybean F. oxysporum disease and significantly reduce F. oxysporum to infect soybean roots. Compared with control and carbendazim treatments, BS06 treatment had higher root biomass, plant height, leaf chlorophyll content, stem base diameter and control efficiency. Our results indicated that BS06 could effectively protect soybean root (BS06 strain might produce substances to inhibit F. oxysporum), which was potentially useful for soybean planting.

Key soil parameters affecting the survival of Panax notoginseng under continuous cropping.

Negative plant-soil feedbacks lead to the poor growth of Panax notoginseng (Sanqi), a well-known herb in Asia and has been used worldwide, under continuous cropping. However, the key soil parameters causing the replant problem are still unclear. Here we conducted a field experiment after 5-year continuous cropping. Sanqi seedlings were cultivated in 7 plots (1.5 m × 2 m), which were randomly assigned along a survival gradient. In total, 13 important soil parameters were measured to understand their relationship with Sanqi's survival. Pearson correlation analysis showed that 6 soil parameters, including phosphatase, urease, cellulase, bacteria/fungi ratio, available N, and pH, were all correlated with Sanqi's survival rate (P < 0.05). Principal component analysis (PCA) indicated that they explained 61% of the variances based on the first component, with soil pH being closely correlated with other parameters affecting Sanqi's survival. The optimum pH for Sanqi growth is about 6.5, but the mean soil pH in the study area is 5.27 (4.86-5.68), therefore it is possible to ameliorate the poor growth of Sanqi by increasing soil pH. This study may also help to reduce the replant problem of other crops under continuous cropping since it is widespread in agricultural production.

An ultrasensitive disposable sandwich-configuration electrochemical immunosensor based on OMC@AuNPs composites and AuPt-MB for alpha-fetoprotein detection.

Early finding and diagnosis are critical for prevention and treatment of hepatocellular carcinoma (HCC). Alpha-fetoprotein (AFP) is a typical biomarker of HCC. Since AFP level can reflect the severity of HCC, it is essential to ensure the accurate detection of AFP. In this study, through a combination of the advantages exhibited by ordered mesoporous carbon (OMC)@gold nanoparticles (AuNPs) composites and AuPt-methylene blue (AuPt-MB), a disposable ultrasensitive sandwich-configuration electrochemical immunosensor for determination of AFP was designed. Characterized by excellent conductivity, highly ordered pore distribution and great surface area, OMC can be effective in promoting electron transfer and loading a large number of AuNPs. In the meantime, AuNPs can also immobilize AFP-Ab1 through Au-N bonds. As a new redox-active species, rod-like AuPt-MB demonstrates high conductivity, uniform morphology and excellent biocompatibility, which makes it capable not only to fix AFP-Ab2, but also to release electrochemical signals. A wide linearity of 10 fg mL-1-100 ng mL-1 and a low detection limit of 3.33 fg mL-1 (S/N = 3) were obtained. Moreover, the proposed immunosensor exhibited acceptable selectivity, high stability and reproducibility. The excellent performance in detecting serum samples endows the proposed immunosensor with broad prospects of extensive application in the detection of disease biomarkers.