Anti-thermal quenching phosphors based on the new phosphate host Ca3.6In3.6(PO4)6.

To enhance the working quality of WLEDs, considerable efforts have been made to upgrade the thermal quenching resistance of existing phosphors or design new anti-thermal quenching (ATQ) phosphors. Developing a new phosphate matrix material with special structural features has great importance for the fabrication of ATQ phosphors. By phase relationship and composition analysis, we have prepared a novel compound Ca3.6In3.6(PO4)6 (CIP). Coupling ab initio and Rietveld refinement techniques, the novel structure of CIP with partly vacant cationic positions was solved. Taking this unique compound as the host and using the inequivalent substitution of Dy3+ for Ca2+, a series of C1-xIP:Dy3+ rice-white emitting phosphors were successfully developed. When the temperature was raised to 423 K, the emission intensity of C1-xIP:xDy3+ (x = 0.01, 0.03, and 0.05) increased to 103.8%, 108.2%, and 104.5% of the original intensity at 298 K, respectively. Except for the strong bonding network and inherent cationic vacancy in the lattice, the ATQ property of the C1-xIP:Dy3+ phosphors is mainly attributed to the generation of interstitial oxygen from the substitution of unequal ions, which releases electrons with the thermal stimulus, causing anomalous emission. Finally, we have explored the quantum efficiency of C1-xIP:0.03Dy3+ phosphor and the working performance of PC-WLED prepared with C1-xIP:0.03Dy3+ phosphor and 365 nm chip. The research work sheds light on the relationship between lattice defects and thermal stability, and meanwhile offers a new strategy for the development of ATQ phosphors.

FGF10 Therapeutic Administration Promotes Mobilization of Injury-Activated Alveolar Progenitors in a Mouse Fibrosis Model.

Idiopathic pulmonary fibrosis (IPF) is a devastating interstitial lung disease with dire consequences and in urgent need of improved therapies. Compelling evidence indicates that damage or dysfunction of AT2s is of central importance in the development of IPF. We recently identified a novel AT2 subpopulation characterized by low SFTPC expression but that is enriched for PD-L1 in mice. These cells represent quiescent, immature AT2 cells during normal homeostasis and expand upon pneumonectomy (PNX) and were consequently named injury-activated alveolar progenitors (IAAPs). FGF10 is shown to play critical roles in lung development, homeostasis, and injury repair demonstrated in genetically engineered mice. In an effort to bridge the gap between the promising properties of endogenous Fgf10 manipulation and therapeutic reality, we here investigated whether the administration of exogenous recombinant FGF10 protein (rFGF10) can provide preventive and/or therapeutic benefit in a mouse model of bleomycin-induced pulmonary fibrosis with a focus on its impact on IAAP dynamics. C57BL/6 mice and SftpcCreERT2/+; tdTomatoflox/+ mice aged 8-10 weeks old were used in this study. To induce the bleomycin (BLM) model, mice were intratracheally (i.t.) instilled with BLM (2 µg/g body weight). BLM injury was induced after a 7-day washout period following tamoxifen induction. A single i.t. injection of rFGF10 (0.05 µg/g body weight) was given on days 0, 7, 14, and 21 after BLM injury. Then, the effects of rFGF10 on BLM-induced fibrosis in lung tissues were assessed by H&E, IHC, Masson's trichrome staining, hydroxyproline and Western blot assays. Immunofluorescence staining and flow cytometry was used to assess the dynamic behavior of AT2 lineage-labeled SftpcPos (IAAPs and mature AT2) during the course of pulmonary fibrosis. We observed that, depending on the timing of administration, rFGF10 exhibited robust preventive or therapeutic efficacy toward BLM-induced fibrosis based on the evaluation of various pathological parameters. Flow cytometric analysis revealed a dynamic expansion of IAAPs for up to 4 weeks following BLM injury while the number of mature AT2s was drastically reduced. Significantly, rFGF10 administration increased both the peak ratio and the duration of IAAPs expansion relative to EpCAMPos cells. Altogether, our results suggest that the administration of rFGF10 exhibits therapeutic potential for IPF most likely by promoting IAAP proliferation and alveolar repair.

Solute carrier family 2 members 1 and 2 as prognostic biomarkers in hepatocellular carcinoma associated with immune infiltration.

BACKGROUND: Metabolic reprogramming has been identified as a core hallmark of cancer. Solute carrier family 2 is a major glucose carrier family. It consists of 14 members, and we mainly study solute carrier family 2 member 1 (SLC2A1) and solute carrier family 2 member 2 (SLC2A2) here. SLC2A1, mainly existing in human erythrocytes, brain endothelial cells, and normal placenta, was found to be increased in hepatocellular carcinoma (HCC), while SLC2A2, the major transporter of the normal liver, was decreased in HCC. AIM: To identify if SLC2A1 and SLC2A2 were associated with immune infiltration in addition to participating in the metabolic reprogramming in HCC. METHODS: The expression levels of SLC2A1 and SLC2A2 were tested in HepG2 cells, HepG215 cells, and multiple databases. The clinical characteristics and survival data of SLC2A1 and SLC2A2 were examined by multiple databases. The correlation between SLC2A1 and SLC2A2 was analyzed by multiple databases. The functions and pathways in which SLC2A1, SLC2A2, and frequently altered neighbor genes were involved were discussed in String. Immune infiltration levels and immune marker genes associated with SLC2A1 and SLC2A2 were discussed from multiple databases. RESULTS: The expression level of SLC2A1 was up-regulated, but the expression level of SLC2A2 was down-regulated in HepG2 cells, HepG215 cells, and liver cancer patients. The expression levels of SLC2A1 and SLC2A2 were related to tumor volume, grade, and stage in HCC. Interestingly, the expression levels of SLC2A1 and SLC2A2 were negatively correlated. Further, high SLC2A1 expression and low SLC2A2 expression were linked to poor overall survival and relapse-free survival. SLC2A1, SLC2A2, and frequently altered neighbor genes played a major role in the occurrence and development of tumors. Notably, SLC2A1 was positively correlated with tumor immune infiltration, while SLC2A2 was negatively correlated with tumor immune infiltration. Particularly, SLC2A2 methylation was positively correlated with lymphocytes. CONCLUSION: SLC2A1 and SLC2A2 are independent therapeutic targets for HCC, and they are quintessential marker molecules for predicting and regulating the number and status of immune cells in HCC.

Relative Deprivation and Game Addiction in Left-Behind Children: A Moderated Mediation.

Previous findings show that relative deprivation has a profound influence on game addiction, but the potential mediating and moderating mechanisms are unclear, especially for left-behind children. The present study therefore examined the relationship between relative deprivation and game addiction, the mediating effect of deviant peer affiliation, and the moderating effect of beliefs about adversity in a sample of left-behind children. A total of 952 left-behind children (mean age = 13.67 years, SD = 1.34) participated in this study. The participants anonymously completed a battery of questionnaires, including the Relative Deprivation Scale, the Deviant Peer Affiliation Scale, the Beliefs about Adversity Scale, the Game Addiction Scale, and demographic variables. After controlling for gender, left-behind category, and socioeconomic status, the moderated mediation model showed that (a) relative deprivation significantly and positively predicted game addiction in left-behind children; (b) The mediation analysis showed that the positive association between relative deprivation and game addiction in left-behind children was mediated by deviant peer affiliation; (c) Beliefs about adversity moderated the association between relative deprivation and deviant peer affiliation and were weaker for left-behind children with higher levels of beliefs about adversity, consistent with the risk-buffering model, but the relationship between relative deprivation and game addiction was stronger for left-behind children with higher levels of beliefs about adversity, consistent with the reverse risk-buffering model. These findings have crucial implications for the prevention and intervention of game addiction in left-behind children.

The Non-Concentration-Quenching Phosphor Ca3Eu2B4O12 for WLED Application.

Commercial white LED devices usually suffer from a high color temperature and poor color rendering. Developing a new, efficient, and stable red phosphor is the key to solving this problem. In this work, a series of pure Ca3Y2-xB4O12:xEu3+ (0 < x ≤ 2) samples, including the new and fully transitional borate phosphor Ca3Eu2B4O12 (CEBO), have been successfully prepared by solid-state reaction synthesis. CEBO is isostructural with Ca3Y2B4O12 (CYBO), belonging to the orthorhombic system with space group Pnma (No. 62). Under optimal 393 nm excitation, this borate exhibits a strong red emission, peaking at 615 nm, with high color purity. Interestingly, the luminescence of CEBO is relatively higher than that of CYBO:Eu3+ phosphors. The quantum yield of this non-concentration-quenching phosphor reaches 95.6%. Furthermore, a warm pc-WLED device has been fabricated by mixing as-prepared CEBO powders and commercial BaMgAl10O17:Eu2+ and (Sr, Ba)2SiO4:Eu2+ phosphors, which exhibits a high color rendering index (Ra = 83.7) along with a color temperature of around 3883 K. The present work indicates that this new borate, with outstanding quantum efficiency and favorable thermal stability, can be used as a red phosphor for application in WLEDs.

Efficient and stable Sr3Eu2B4O12 red phosphor benefiting from low symmetry and distorted local environment.

The development of suitable red phosphors to obtain improved white color stands a good chance to serve in the new generation of white light-emitting diodes. Owing to multi-elements via doping and oxidation of reduced valence state of lanthanide or transition metal ions, most of the reported phosphors usually suffer from complex synthetic processes and unstable color of the lighting industry cycle. In this work, we present a new red emitting and stable Sr3Eu2B4O12 phosphor with regard to its special structure. It crystallizes as an orthorhombic cell, with Sr and Eu atoms co-occupying three different lattice sites in the space group of Pnma (no. 62). It is proposed that the long bond distance between activators minimizes the content quenching, while the high disorder of location restricts the thermal quenching. This phosphor emits bright red light with good color purity under UV excitation, with the luminescence intensity and quantum yield tunable via the fabrication temperature. Through a preliminary optimization of the synthesis process, the Sr3Eu2B4O12 phosphor prepared at 1250 °C has high quantum yields of about 94.7% and excellent thermal stability of 85.6% intensity retention at 150 °C relative to the initial value at room temperature. The calculated Judd-Ofelt intensity parameters (Ω2, Ω4) further clarified that the Eu3+ site in Sr3Eu2B4O12 had lower symmetry without an inversion center, and more distorted local environment and structural rigidity of the host, predicting excellent thermal stability. Finally, a warm pc-WLED device has been produced by mixing as-prepared Sr3Eu2B4O12 powders and commercial BaMgAl10O17:Eu2+ and (Sr, Ba)2SiO4:Eu2+ phosphors, which exhibits a high color rendering index (Ra = 83.4) along with a color temperature at around 4102 K. The present work indicates that the Sr3Eu2B4O12 phosphor is an efficient red component with excellent thermal stability for white-light production of near-UV-excited w-LEDs.

Are Emotion Regulation Strategies Different among 3-6-Year-Old Aggressive Children? Evidence from China.

BACKGROUND: During the long-time home quarantine due to COVID-19, preschool-age children can be easily stricken by negative emotions, which give rise to aggressive behaviors. Aggressive behaviors are of different types at the preschool stage. We aimed to investigate the differences of emotion regulation strategies among children age 3-6 yr old with different aggression types and explore the relationship between emotion regulation strategies and aggressive behaviors. METHODS: The aggressive behaviors of 1,187 children sampled (event sampling method) from 5 kindergartens in five cities in Henan Province of China were observed on the spot in 2020. Three aggression types (i.e., physical, verbal, and indirect) were selected to conduct a questionnaire survey on emotion regulation strategies and discuss the differences among aggressive children in emotion regulation strategies. RESULTS: Children of different genders are significantly different in aggressive behaviors and problem solving, as well as children at different age levels in self-comfort, passive reaction, and negative regulation strategies. Significant interaction exists between gender and aggression but not in negative regulation strategy; significant interaction also exists between age and aggression but not in cognitive reconstruction, substitutive activity, and aggressive behavior. Significant differences exist among children of different aggression types in positive and negative regulation strategies. The discrimination accuracy of emotion regulation strategies for aggression types is 66.5%. CONCLUSION: Significant differences exist among 3-6-yr-old aggressive children in emotion regulation strategies, and emotion regulation strategies can effectively distinguish aggressive children of different types.

Identification of a novel strain, Streptomyces blastmyceticus JZB130180, and evaluation of its biocontrol efficacy against Monilinia fructicola.

Peach brown rot, caused by Monilinia fructicola, is one of the most serious peach diseases. A strain belonging to the Actinomycetales, named Streptomyces blastmyceticus JZB130180, was found to have a strong inhibitory effect on M. fructicola in confrontation culture. Following the inoculation of peaches in vitro, it was revealed that the fermentation broth of S. blastmyceticus JZB130180 had a significant inhibitory effect on disease development by M. fructicola. The fermentation broth of S. blastmyceticus JZB130180 had an EC50 (concentration for 50% of maximal effect) of 38.3 µg/mL against M. fructicola, as determined in an indoor toxicity test. Analysis of the physicochemical properties of the fermentation broth revealed that it was tolerant of acid and alkaline conditions, temperature, and ultraviolet radiation. In addition, chitinase, cellulase, and protease were also found to be secreted by the strain. The results of this study suggest that S. blastmyceticus JZB130180 may be used for the biocontrol of peach brown rot.

Layered Crystal Structure, Color-Tunable Photoluminescence, and Excellent Thermal Stability of MgIn2P4O14 Phosphate-Based Phosphors.

Single-component white phosphors stand a good chance to serve in the next-generation high-power white light-emitting diodes. Because of low thermal stability and containing lanthanide ions with reduced valence state, most of reported phosphors usually suffer unstable color of lighting for practical packaging and comparably complex synthetic processes. In this work, we present a type of novel color-tunable blue-white-yellow-emitting MgIn2P4O14:Tm3+/Dy3+ phosphor with high thermal stability, which can be easily fabricated in air. Under UV excitation, the MgIn2P4O14:Tm0.02Dy0.03 white phosphor exhibits negligible thermal-quenching behavior, with a 99.5% intensity retention at 150 °C, relative to its initial value at room temperature. The phosphor host MgIn2P4O14 was synthesized and reported for the first time. MgIn2P4O14 crystallizes in the space group of C2/c (No. 15) with a novel layered structure built of alternate anionic and cationic layers. Its disordering structure, with Mg and In atoms co-occupying the same site, is believed to facilitate the energy transfer between rare-earth ions and benefit by sustaining the luminescence with increasing temperature. The measured absolute quantum yields of MgIn2P4O14:Dy0.04, MgIn2P4O14:Tm0.01Dy0.04, and MgIn2P4O14:Tm0.02Dy0.03 phosphors under the excitation of 351 nm ultraviolet radiation are 70.50%, 53.24%, and 52.31%, respectively. Present work indicates that the novel layered MgIn2P4O14 is a promising candidate as a single-component white phosphor host with an excellent thermal stability for near-UV-excited white-light-emitting diodes (wLEDs).

Metschnikowia persici sp. nov., A Novel Protease-Producing Yeast Species from China.

Three yeast strains, named as FHL-A, FHL-B, and FHL-C, were isolated from peach fruit surfaces collected from different regions in the North of China highly produced protease and were presented as single separate group in the genus Metschnikowia by sequence comparisons of 26S rRNA gene D1/D2 domain and internal transcribed spacer (ITS) region. BLASTn alignments on NCBI showed that the similarity of 26S rRNA gene sequences of the three strains to all sequences of other yeasts accessed into the GenBank/EMBL/DDBJ and other database was very low (≦93%). The phylogenetic tree based on the D1/D2 region of 26S rRNA gene sequences revealed that three strains are most closely related to Metschnikowia koreensis KCTC 7828T (AF257272.1) (sequence similarity: 93.0%) and Metschnikowia reukaufii CBS9709T (AJ716113.1) (sequence similarity: 93.0%). However, the strains are distinguished from M. koreensis by its non-assimilation of galactose, ribitol, and D-xylose, and by its growth at 37 °C or in vitamin-free medium, and are notably different from M. reukaufii by its non-assimilation of galactose, D-xylose, D-arabinose, and D-ribose, and by its growth at 35 °C or in vitamin-free medium. The strain FHL-B formed asci in V8 juice sporulation medium for 3 weeks. Therefore, the name Metschnikowia persici is proposed for the novel species, with FHL-B (= CBS12815T = CFCC 3578T) as the type strain.

[Comparition of ecological security stress effects of artificial landscapes on natural landscapes in different rapid urban sprawl areas]. / ä¸åŒç±»åž‹åŸŽå¸‚å¿«é€Ÿæ‰©å¼ åŒºåŸŸäººå·¥æ™¯è§‚å¯¹è‡ªç„¶æ™¯è§‚çš„ç”Ÿæ€å®‰å ¨èƒè¿«æ•ˆåº”æ¯”è¾ƒ.

The expansion of built-up area will cause stress effect on the regional natural ecological security pattern during urbanization process. Taking rapid expanding regions of four inland and coastal cities as study areas, including Tongzhou in Beijing, Zhengding in Hebei, Tanggu in Tianjin and Xiamen in Fujian, we constructed regional landscape stress indexes according to the principle of landscape ecology and comparatively analyzed the landscape pattern characteristics of rapid expanding regions and the differences of stress effect of artificial landscapes on four natural landscapes ecological security pattern in the process of rapid urbanization. Results showed that landscape erosion indexes of Tongzhou, Zhengding, Tanggu and Xiamen in 2015 were 1.039, 0.996, 1.239 and 0.945, respectively, which indicated that the natural landscapes were eroded significantly. Natural landscape types of those four regions presented different threatened levels. Among all natural landscape types, unused land and waters were worst threatened in Tongzhou, Zhengding and Tanggu, while in Xiamen cultivated land and waters showed the highest threat levels. The waters threat indexes of those four areas were all more than 0.743. Landscape isolation indexes of waters and unused land of the inland cities were greater than those of coastal cities, which meant water distribution of inland cities in the space was less gathered than that of coastal cities. Besides, compared with the other natural landscape, unused land and waters suffered the largest stress from artificial landscapes.

A two-domain protein triggers heat shock pathway and necrosis pathway both in model plant and nematode.

The entomopathogen Bacillus thuringiensis is equipped with multiple virulent factors. The genome sequence of B. thuringiensis YBT1520 revealed the presence of a two-domain protein named Nel which is composed of a necrosis-inducing phytophthora protein 1-like domain found in phytopathogens and a ricin B-like lectin domain. The merging of two distantly related domains is relatively rare. Nel induced necrosis and pathogen-triggered immunity (PTI) on model plants. The Nel also exhibited inhibition activity to nematode. Microscopic observation showed that the toxicity of Nel to nematodes targets the intestine. Quantitative proteomics revealed that Nel stimulated the host defence. The Nel thus possesses dual roles, as both toxin and elicitor. Remarkably, the Nel protein triggered a similar response, induction of the heat shock pathway and the necrosis pathway, in both model plants and nematodes. The unusual ability of Nel to function across kingdom suggests a highly conserved mechanism in eukaryotes that predates the divergence of plants and animal. It is also speculated that the two-domain protein is the result of horizontal gene transfer (HGT) between phytopathogens and entomopathogens. Our results provide an example that HGT occurs between members of different species or even genera with lower frequency are particularly important for evolution of new bacterial pathogen lineages with new virulence. Bacillus thuringiensis occupies the same ecological niches, plant and soil, as phytopathogens, providing the opportunity for gene exchange.

Candida pruni sp. nov. is a new yeast species with antagonistic potential against brown rot of peaches.

Brown rot caused by Monilinia spp. is among the most important postharvest diseases of commercially grown stone fruits, and application of antagonistic yeasts to control brown rot is one promising strategy alternative to chemical fungicides. In this research, new yeast strains were isolated and tested for their activity against peach brown rot caused by Monilinia fructicola. Three yeast strains were originally isolated from the surface of plums (cv Chinese Angelino) collected in the north of China. In artificially wounded inoculation tests, the yeast reduced the brown rot incidence to 20 %. The population of the yeast within inoculated wounds on peaches significantly increased at 25 °C from an initial level of 5.0×10(6) to 4.45×10(7) CFU per wound after 1 day. The antagonistic strains were belonging to a new species of the genus Candida by sequence comparisons of 26 S rDNA D1/D2 domain and internal transcribed spacer region. The strains are most closely related to C. asparagi, C. musae and C. fructus on the basis of the phylogenetic trees based on the D1/D2 region of 26S rDNA. However, the strains are notably different from C. asparagi, C. musae and C. fructus, in morphological and physiological characteristics. Therefore, the name Candida pruni is proposed for the novel species, with sp-Quan (=CBS12814T=KCTC 27526T=GCMC 6582T) as the type strain. Our study showed that Candida pruni is a novel yeast species with potential biocontrol against brown rot caused by M. fructicola on peaches.

Diversity Analysis of Bacterial Community from Permafrost Soil of Mo-he in China.

The permafrost soil of Mo-he in Northeast China presents a typical cold environment colonized by psychrophilic microorganisms. This study is aimed at assessing the bacterial communities of permafrost soil of Mo-he in China by sequencing the 16S rRNA genes and Mothur analysis. PCR products with universal 16S rRNA gene primers were cloned and partially sequenced, and bacterial identification at the species was performed by comparative analysis with the GenBank/EMBL/DDBJ database. A total of 266 clones were obtained with the average length of 1,050 bp. Mothur analysis showed that the coverage value of clone library was 53.78 %, Shannon diversity (H) was 4.03, Simpson diversity value was 0.018, and 74 operational taxonomic units were generated. Through phylogenetic assignment using BLASTN by more than 97 % similarity, a total of 87 tentative taxa were identified. The majority of bacterial sequences recovered in this study belonged to the Acidobacteria, Proteobacteria, Verrucomicrobia, Bacteroidetes, Chloroflexi and Chlorobi. Among them, Acidobacteria are dominant community, accounting for 30.1 % of total bacteria, followed by Proteobacteria which accounted for 22.2 %. This result reflected the acidic characteristics of the permafrost soil of which pH value was 6.0. Our study indicated that the permafrost soil of Mo-he in China has a high diversity of bacteria and represents a vast potential resource of novel bacteria. As far as we knew, this is the first report on bacterial diversity of permafrost soil of Mo-he in China.

Identification of an antifungal metabolite produced by a potential biocontrol Actinomyces strain A01 / Identificação de um metabólito antifúngico produzido pela cepa Actinomyces A01

Actinomyces strain A01 was isolated from soil of a vegetable field in the suburb of Beijing, China. According to the morphological, cultural, physiological and biochemical characteristics, and 16S rDNA sequence analysis, strain A01 was identified as Streptomyces lydicus. In the antimicrobial spectrum test strain A01 presented a stable and strong inhibitory activity against several plant pathogenic fungi such as Fusarium oxysporum, Botrytis cinerea, Monilinia laxa, etc. However, no antibacterial activity was found. In pot experiments in greenhouse, the development of tomato gray mold was markedly suppressed by treatment with the fermentation broth of the strain A01, and the control efficacy was higher than those of Pyrimethanil and Polyoxin. A main antifungal compound (purity 99.503 percent) was obtained from the fermentation broth of strain A01 using column chromatography and HPLC. The chemical structural analysis with UV, IR, MS, and NMR confirmed that the compound produced by the strain A01 is natamycin, a polyene antibiotic produced by S. chattanovgensis, S. natalensis, and S. gilvosporeus, widely used as a natural biological preservative for food according to previous reports. The present study revealed a new producing strain of natamycin and its potential application as a biological control agent for fungal plant diseases.

A cepa Actinomyces A01 foi isolada do solo de um campo agrícola no subúrbio de Beijing, China. De acordo com as características morfológicas, culturais, fisiológicas e bioquímicas, e análise da sequência 16S rDNA , a cepa A01 foi identificada como Streptomyces lydicus. Nos testes de espectro antimicrobiano, a cepa A01 apresentou atividade inibitória intensa e estável contra vários fungos patogênicos para plantas, como Fusarium oxysporum, Botrytis cinerea, Monilia laxa, etc. Entretanto, não foi encontrada atividade antibacteriana. Em experimentos em estufas, o desenvolvimento do fungo cinza do tomate foi fortemente inibido pelo tratamento com o caldo de fermentação da cepa A01, com eficiência superior à do pyremethanil e polyoxin. Por cromatografia em coluna e HPLC, obteve-se um composto fúngico (pureza 99,503 por cento), cuja análise estrutural por UV, IR, MS e NMR revelou ser natamicina, um antibiótico polienico produzido por S. chattanovgensis, S. natalensis e S.gilvosporeus, empregado como conservador biológico natural em alimentos. O presente estudo relata a detecção de uma nova cepa produtora de natamicina e sua aplicação potencial como um agente de controle biológico de doenças fúngicas em plantas.

Identification of an antifungal metabolite produced by a potential biocontrol Actinomyces strain A01.

Actinomyces strain A01 was isolated from soil of a vegetable field in the suburb of Beijing, China. According to the morphological, cultural, physiological and biochemical characteristics, and 16S rDNA sequence analysis, strain A01 was identified as Streptomyces lydicus. In the antimicrobial spectrum test strain A01 presented a stable and strong inhibitory activity against several plant pathogenic fungi such as Fusarium oxysporum, Botrytis cinerea, Monilinia laxa, etc. However, no antibacterial activity was found. In pot experiments in greenhouse, the development of tomato gray mold was markedly suppressed by treatment with the fermentation broth of the strain A01, and the control efficacy was higher than those of Pyrimethanil and Polyoxin. A main antifungal compound (purity 99.503%) was obtained from the fermentation broth of strain A01 using column chromatography and HPLC. The chemical structural analysis with U V, IR, MS, and NMR confirmed that the compound produced by the strain A01 is natamycin, a polyene antibiotic produced by S. chattanovgensis, S. natalensis, and S. gilvosporeus, widely used as a natural biological preservative for food according to previous reports. The present study revealed a new producing strain of natamycin and its potential application as a biological control agent for fungal plant diseases.

[Cloning, expression of the CP gene and antiserum preparation of zucchini yellow mosaic virus infecting Benincasa hispida Cogn. var. chieh-qua How].

A Guangzhou isolate of ZYMV infecting Benincasa hispida Cogn. var. chieh-qua How was identified by indicator tests and partial sequence amplification. The coat protein (CP) gene of this virus was amplified by RT-PCR, and ligated to the expression vector pET-22b(+). The recombinant plasmid pET-ZCP was transformed into E. coli BL21 (DE3) and then induced to express by IPTG. It was shown that the CP gene was highly expressed by SDS-PAGE and Western blot analysis. The molecular weight of the recombinant protein was about 33.0 kD. Antiserum with high specificity was produced after the rabbit was immunized with purified recombinant protein, and the titer was determined to be 1/4096 by antigen coating plate-ELISA (ACP-ELISA).