Crystal Field Engineering Inducing Transformation from Narrow Band of Eu3+ to Broadband of Eu2.

The complete transformation from narrow peak emission of Eu3+ to broadband emission of Eu2+ was first realized in La1-xSr2+xAl1-xSixO5:Eu series solutions relying on crystal field engineering and adjustment of synthesis parameters. The original red phosphor La0.97Sr2AlO5:0.03Eu3+peaks at 703 nm originated from 5D0 →7F4 transition of Eu3+ under 395 nm excitation. As the x value regularly increased, Sr2SiO4-type green phosphor La0.17Sr2.8Al0.2Si0.8O5:0.03Eu2+ was synthesized at x = 0.8, which can be efficiently excited by UV/blue light chips. Moreover, when x > 0.975, Sr3SiO5:Eu2+ type broadband orange phosphor Sr2.945Al0.025Si0.975O5:0.03Eu2+ with excellent thermal stability (91.3% peak intensity at 150 °C) was obtained. Variations in the crystal structure, phase, and luminescence properties were studied in detail. We hope this work can provide a reference that solid solution between distinct but structurally related systems is a strategy to explore the possible phosphors for phosphor-converted light-emitting diodes.

Whole-Genome Sequencing of Fusarium oxysporum f. sp. cucumerinum Strain Race-4 Infecting Cucumber in China.

Fusarium oxysporum f. sp. cucumerinum, which causes root and vascular wilting, is one of the most devastating diseases infecting cucumber. Here, we report the first genome resource with high-quality assembly for F. oxysporum f. sp. cucumerinum strain Race-4, which is primarily endemic to China. The genome was 59.11 Mb in size and consisted of 48 scaffolds with an N50 of 3.87 Mb using PacBio long reads (301.77×) sequencing, and encodes 14,898 proteins from analyzing RNA-seq data. Gene annotations identified pathogen-host interaction genes, fungal virulence factors, secreted proteins, transcription factors, and secondary metabolite biosynthesis gene. Moreover, functional genes reported in previous studies were also identified in the genome of Race-4. These genes and genome resource may play important roles in understanding F. oxysporum f. sp. cucumerinum-cucumber interactions and will be useful for further research.

The vegetable SNP database: An integrated resource for plant breeders and scientists.

Single nucleotide polymorphisms (SNPs) are widely used in genetic research and molecular breeding. To date, the genomes of many vegetable crops have been assembled, and hundreds of core germplasms for each vegetable have been sequenced. However, these data are not currently easily accessible because they are stored on different public databases. Therefore, a vegetable crop SNP database should be developed that hosts SNPs demonstrated to have a high success rate in genotyping for genetic research (herein, "alpha SNPs"). We constructed a database (VegSNPDB, http://www.vegsnpdb.cn/) containing the sequence data of 2032 germplasms from 16 vegetable crop species. VegSNPDB hosts 118,725,944 SNPs of which 4,877,305 were alpha SNPs. SNPs can be searched by chromosome number, position, SNP type, genetic population, or specific individuals, as well as the values of MAF, PIC, and heterozygosity. We hope that VegSNPDB will become an important SNP database for the vegetable research community.

CsATAF1 Positively Regulates Drought Stress Tolerance by an ABA-Dependent Pathway and by Promoting ROS Scavenging in Cucumber.

The NAC transcription factors play vital roles in responding to drought stress in plants; however, the molecular mechanisms remain largely unknown in cucumber. Suppression of CsATAF1 via RNA interference (RNAi) weakened drought stress tolerance in cucumber due to a higher water loss rate in leaves, a higher level of hydrogen peroxide (H2O2) and superoxide radicals (O2·-), increased malondialdehyde (MDA) content, lower Fv/Fm ratios and lower antioxidant enzyme activity. The analysis of root length and stomatal apertures showed that CsATAF1-RNAi cucumber plants were less responsive to ABA. In contrast, CsATAF1-overexpression (OE) plants showed increased drought stress tolerance and sensitivity to ABA. Quantitative PCR (qPCR) analysis showed that expression of several stress-responsive genes was significantly up-regulated in CsATAF1-OE transformants and down-regulated in CsATAF1-RNAi transformants. CsABI5, CsCu-ZnSOD and CsDREB2C were verified as direct target genes of CsATAF1. Yeast one-hybrid analysis and electrophoretic mobility shift assay (EMSA) further substantiated that CsATAF1 bound to the promoters of CsABI5, CsCu-ZnSOD and CsDREB2C. Transient expression in tobacco leaves and cucumber protoplasts showed that CsATAF1 directly up-regulated the expression of CsABI5, CsCu-ZnSOD and CsDREB2C. Our results demonstrated that CsATAF1 functioned as a positive regulator in response to drought stress by an ABA-dependent pathway and decreasing reactive oxygen species (ROS) accumulation in cucumber.

Fine genetic mapping of target leaf spot resistance gene cca-3 in cucumber, Cucumis sativus L.

KEY MESSAGE: The cucumber target leaf spot resistance gene cca - 3 was fine mapped in a 79-kb region harboring a CC-NB-ARC type R gene that may be responsible for the hypersensitive responses to infection of the target leaf spot pathogen in cucumber. The target leaf spot (TLS) is one of the most important foliar diseases in cucumber (Cucumis sativus L.). In this study, we conducted fine genetic mapping of a simply inherited recessive resistance gene, cca-3 against TLS with 193 F2:3 families and 890 F2 plants derived from the resistant cucumber inbred line D31 and the susceptible line D5. Initial mapping with microsatellite markers and bulked segregant analysis placed cca-3 in a 2.5-Mbp region of cucumber chromosome 6. The D5 and D31 lines were re-sequenced at 10× genome coverage to explore new markers in the target region. Genetic mapping in the large F2 population delimited the cca-3 locus in a 79-kb region with flanking markers Indel16874230 and Indel16953846. Additional fine mapping and gene annotation in this region revealed that a CC-NB-ARC type resistance gene analog, Csa6M375730, seems to be the candidate gene for cca-3. One single nucleotide polymorphism (SNP) was found in the NB-ARC domain of this candidate gene sequence between D31 and D5 that may lead to amino acid change, thus altering the function of the conserved NB-ARC motif. This SNP was validated in the segregating population as well as 24 independent cucumber lines. There was significantly higher level of cca-3 expression in the leaves of D5 (susceptible) than in D31 (resistant), and the expression level was positively correlated with the areas of necrotic spots on leaves after inoculation. It seems the cca-3 resistance gene was able to induce hypersensitive responses to the infection by TLS pathogen.

Oxynitride K2Ba6.72Si16O40-1.5yNy:0.28Eu2+ phosphor with high thermal stability realized by crystal field engineering.

Extensive research has gone into modifying the chemical composition of phosphors to achieve desirable optical properties. Here, oxynitride phosphors K2Ba6.72Si16O40-1.5yNy:0.28Eu2+ were synthesized by introducing N3- (y) into a K2Ba6.72Si16O40:0.28Eu2+ lattice. An uneven shrinking of the cell parameters a, b, and c was observed through a combination of X-ray diffraction studies and Rietveld refinements. This shrinking caused a large centroid shift (εc) and splitting of the 5d energy level (εcfs), thus inducing the broadening of the excitation spectra (104 → 127 nm, y = 0 → y = 12) and the red shift of the emission spectra (501 → 543 nm, y = 0 → y = 12). The modified series of samples have a broad excitation spectrum, suitable of use in UV, near-UV, and blue light-emitting LEDs. In addition, the optimal sample, K2Ba6.72Si16O31N6:0.28Eu2+, benefits from an increased activation energy and thermal stability.

Effects of the pestle needle therapy, a type of acupoint stimulation, on post-hemorrhoidectomy pain: A randomized controlled trial.

BACKGROUND: Hemorrhoids are one of the most common conditions that lead to surgery, and until now surgical hemorrhoidectomy has been the major effective treatment. Post-operative pain from hemorrhoidectomy has been experienced by thousands of patients and remains a major inconvenience of the operation. OBJECTIVE: This study evaluates the clinical efficacy of the pestle needle therapy, an acupoint stimulation method, for relief of post-hemorrhoidectomy pain. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS: This was a single-center, patient-assessor-blinded and randomized controlled trial with 154 patients receiving Milligan hemorrhoidectomy surgery. Eligible patients were randomly assigned to either a treatment group or a control group at a ratio of 1:1. The treatment group received the pestle needle therapy, with manual stimulation at Yaoshu (DU2), Mingmen (DU4), Changqiang (DU1), Chengshan (BL57), Erbai (EX-UE2) and the perianal points (1, 3, 5, 7, 9, and 11o'clock around the lesion); while the control group received a sham treatment with very light pressure. Three sessions of treatment were performed at 30 min, 4 h and 12 h after the surgery, and each lasted for 15 min. MAIN OUTCOME MEASURES: The primary outcome was post-operative pain measured with the visual analogue scale (VAS) at 12 h after surgery. The secondary outcomes included the VAS scores measured at 0.5, 2, 4, 6, 8, 24 and 48 h after surgery, the analgesic dose, the time and the VAS score of the patients' first defecation after surgery, as well as the Hamilton Rating Scale for Anxiety (HAMA) evaluated before discharge. RESULTS: The mean pain score of the treatment group was significantly lower than that of the control group (3.10 ± 1.27 vs 4.82 ± 1.29; P < 0.001) at 12 h after surgery. Compared with the control group, patients in the treatment group needed a smaller dose of analgesic within the first 24 hours after surgery (P = 0.002); and their HAMA scores before discharge were lower (4.07 ± 2.40 vs 5.10 ± 2.45, P = 0.009). Compared to the treatment group, patients in the control group had a greater time to the first defecation after surgery ([52.34 ± 15.72] h vs [27.08 ± 13.68] h; P < 0.001), but there was no difference in their VAS scores at the first defecation (P = 0.092). CONCLUSION: The pestle needle therapy was effective for relieving pain, reducing anxiety and improving bowel function after hemorrhoidectomy, and it is worthy of clinical application.

Target SSR-Seq: A Novel SSR Genotyping Technology Associate With Perfect SSRs in Genetic Analysis of Cucumber Varieties.

Simple sequence repeats (SSR) - also known as microsatellites - have been used extensively in genetic analysis, fine mapping, quantitative trait locus (QTL) mapping, as well as marker-assisted selection (MAS) breeding and other techniques. Despite a plethora of studies reporting that perfect SSRs with stable motifs and flanking sequences are more efficient for genetic research, the lack of a high throughput technology for SSR genotyping has limited their use as genetic targets in many crops. In this study, we developed a technology called Target SSR-seq that combined the multiplexed amplification of perfect SSRs with high throughput sequencing. This method can genotype plenty of SSR loci in hundreds of samples with highly accurate results, due to the substantial coverage afforded by high throughput sequencing. We also detected 844 perfect SSRs based on 182 resequencing datasets in cucumber, of which 91 SSRs were selected for Target SSR-seq. Finally, 122 SSRs, including 31 SSRs for varieties identification, were used to genotype 382 key cucumber varieties readily available in Chinese markets using our Target SSR-seq method. Libraries of PCR products were constructed and then sequenced on the Illumina HiSeq X Ten platform. Bioinformatics analysis revealed that 111 filtered SSRs were accurately genotyped with an average coverage of 1289× at an extremely low cost; furthermore, 398 alleles were observed in 382 cucumber cultivars. Genetic analysis identified four populations: northern China type, southern China type, European type, and Xishuangbanna type. Moreover, we acquired a set of 16 core SSRs for the identification of 382 cucumber varieties, of which 42 were isolated as backbone cucumber varieties. This study demonstrated that Target SSR-seq is a novel and efficient method for genetic research.

Comparative analysis of miRNA and mRNA abundance in determinate cucumber by high-throughput sequencing.

Determinate cucumber is a type of short vines, fewer nodes, and terminal flowers, it is suitable for high-density planting and available harvesting in field cultivation, whereas the indeterminate cucumber is preferred to cultivate in greenhouses. However, many biotic or abiotic stresses could lead indeterminate cucumber to be determinate in greenhouse cultivation, which may decrease yield and fruit quality. Therefore, it is urgent and essential to investigate the key factors forming determinate and terminal flowering in cucumber. In this study, two close background inbred lines were selected and conducted the miRNA and mRNA high throughput sequencing. Interestingly, ethylene-associated miRNAs and mRNAs were intensively obtained, indicating that the plant hormone ethylene is a key factor impacting determinate and terminal flowering in cucumber. The ethylene metabolites analysis showed that significant higher ethylene was observed in determinate line than that in the indeterminate line. The RT-qPCR validation of ethylene related miRNAs Cas-miR172, Cas-miR396, and Cas-miR414 and their target mRNAs showed a significant negative correlation. These data suggested that ethylene-associated miRNAs might affect determinate and terminal flower phenotypes by regulating their target genes expression. This study not only provides a potential molecular mechanism for determinate formation in cucumber but also establishes a method to demonstrate important physiological processes through the comprehensive association of miRNA and mRNA high-throughput sequencing.

Identification and characterisation of Dof transcription factors in the cucumber genome.

Cucumber is vulnerable to many foliage diseases. Recent studies reported cloning of candidate genes for several diseases in cucumber; however, the exact defence mechanisms remain unclear. Dof genes have been shown to play significant roles in plant growth, development, and responses to biotic and abiotic stresses. Dof genes coding for plant-specific transcription factors can promote large-scale expression of defence-related genes at whole genome level. The genes in the family have been identified and characterized in several plant species, but not in cucumber. In the present study, we identified 36 CsDof members from the cucumber draft genomes which could be classified into eight groups. The proportions of the CsDof family genes, duplication events, chromosomal locations, cis-elements and miRNA target sites were comprehensively investigated. Consequently, we analysed the expression patterns of CsDof genes in specific tissues and their response to two biotic stresses (watermelon mosaic virus and downy mildew). These results indicated that CsDof may be involved in resistance to biotic stresses in cucumber.

[Integrative expression of XynB of Aspergillus niger UV-11 in industrial yeast].

The cDNA sequence of beta-xylanase gene (xynB) was cloned from Aspergillus niger UV-11. It was inserted into the yeast expression vector and the recombinant plasmid pAX2 was obtained. The plasmid pAX2 was introduced into an industrial S. cerevisiae 2.346 and integrated into yeast genome by co-transformation of a YEPtype plasmid pBEJ16 carrying G418 resistance. The stable engineered yeast strain XY2 was obtained. It could express and secret extracellular xylanase, and enhance the alcohol production in wheat flour fermentation compared with the host strain S. cerevisiae 2.346.

[Phylogenetic diversity analyse of rumen bacteria using culture independent method].

Culture independent method was used to study the diversity of rumen bacteria. Molecular diversity of rumen bacteria was analyzed by PCR amplification and sequencing of 16S rDNA clone libraries prepared from the rumen content of Holstein cows. The total DNA directly extracted from rumen fluid was used as PCR template. Bacteria universal primer 27F and 1492R was used as primer. Random clones, containing almost full size 16S rDNA sequences (about 1.5 kb long), were sequenced and subjected to an on line similarity search. The 16S rDNA sequence analysis indicated that more than half of the sequences belonged to the not-yet-cultured groups. The 16S rDNA similarity levels with cultured species was less than 90%. The bacterial community structure was also revealed by phylogenetic tree of known sequences and selected sequence. In the library from the rumen fluid, the sequences were mainly affiliated with the following major phyla: low G + C Gram-positive bacteria, Cytophaga-Flexibacter-Bacteroides, and the remaining sequences were placed within not-yet-uncultured groups that had an uncertain affiliation. These several sequences are likely to represent novel taxonomic groupings. The nucleotide sequences have been submitted to the GenBank/EMBL /DDBJ databases under accession numbers AY986777-AY986791.

[Expression of B-glucosidase gene of Sacchromycopsis fibuligera in Pichia pastoris].

A beta-Glucosidase gene (BGL 1) was amplified with PCR from the total DNA of Sacchromycopsis fibuligera, and was linked with pGEM-T vector. After cut down by restriction enzyme from pGEM-T vector, BGL 1 was inserted into the expression vector pPIC9K of Pichia pastoris in reading frame with alpha-factor secreting signal peptide sequence to construct the recombinant plasmid pSHL9K. The recombinant plasmid pSHL9K was transformed into Pichia pastoris GS115 with electroporation. The recombinant Pichia pastoris strains which could efficiently secret recombinant beta-Glucosidase were selected. The optimum temperature of the recombinant beta-Glucosidase was 50degreesC, and the optimum pH was 5.4. The activity of beta-Glucosidase could reach to 47U/mL in the culture medium.

Synthesis, structure, and luminescence properties of SrSiAl2O3N2:Eu(2+) phosphors for light-emitting devices and field emission displays.

A series of SrSiAl2O3N2:Eu(2+) (0.005 ≤x≤ 0.05) phosphors were successfully synthesized through a pressureless, facile, and efficient solid state route. The crystal structure, band structure, and their photoluminescence and cathodoluminescence properties were investigated in detail. The phosphors exhibit rod shape morphology with a uniform Eu(2+) distribution. Under n-UV excitation the emission spectra shift from 477 to 497 nm with an increase of Eu(2+) concentration. The concentration quenching mechanism of Eu(2+) emission was dominated by the dipole-dipole interaction. The thermal stability is comparable to that of the commercial Ba2SiO4:Eu(2+) phosphor. The phosphor also exhibits high current saturation and high resistance under low voltage electron bombardment. All the results indicate that the SrSiAl2O3N2:Eu(2+) phosphors can be considered as candidates for application in both white LEDs and FEDs.

Expression patterns of genes encoding plasma membrane aquaporins during fruit development in cucumber (Cucumis sativus L.).

Aquaporins are membrane channels precisely regulating water movement through cell membranes in most living organisms. Despite the advances in the physiology of fruit development, their participation during fruit development in cucumber still barely understood. In this paper, the expressions of 12 genes encoding plasma membrane intrinsic proteins (PIPs) were analyzed during cucumber fruit development in our work. Based on the homology search with known PIPs from rice, Arabidopsis and strawberry, 12 cucumber PIP genes subfamily members were identified. Cellular localization assays indicated that CsPIPs were localized in the plasma membrane. The qRT-PCR analysis of CsPIPs showed that 12 CsPIPs were differentially expressed during fruit development. These results suggest that 12 genes encoding plasma membrane intrinsic proteins (CsPIPs) play very important roles in cucumber life cycle and the data generated will be helpful in understanding their precise roles during fruit development in cucumber.

Homologous overexpression of alkyl hydroperoxide reductase subunit C (ahpC) protects Bifidobacterium longum strain NCC2705 from oxidative stress.

The ability to manage reactive oxygen species (ROS) effectively is crucial for the survival of gut bifidobacteria under conditions of oxidative stress. Alkyl hydroperoxide reductase catalytic subunit C (ahpC) of Bifidobacterium longum responds to various oxidative stresses. In this study, an ahpC-overexpressing transformant of B. longum strain NCC2705 was constructed to investigate the role and function of ahpC in oxidative stresses inflicted by treatments with hydrogen peroxide (H2O2), cumene hydroperoxide, and aerobic oxygen. Results indicated that in B. longum, AhpC is the primary scavenger of endogenous H2O2 generated by aerobic metabolism, but it is unable to detoxify high concentrations of exogenous H2O2. The ahpC-overexpressing B. longum strain showed increased resistance to organic hydroperoxide killing, increased viability under aerobic growth, but decreased resistance to exogenous H2O2 in comparison to the control strain. Analysis of genes from the oxidative stress-defense pathway encoding oxygen-independent coproporphyrinogen III oxidase (HemN), NADH oxidase (Nox) and thioredoxin reductase-like protein (TrxB) showed increased transcript levels in the ahpC-overexpressing vs. control strain. These findings suggest that elevated ahpC expression facilitates or activates the different electron donor-dependent ROS-elimination pathways in B. longum's response to oxidative stress.

[Expression of endo-beta-mannanase gene from Trichoderma reesei in Pichia pastoris].

Complete mannanase gene with two introns was cloned from Trichoderrna reesei by PCR. The two introns were then removed by overlap extension PCR. The gene encoding the mature mannanase protein was inserted into the expression vector pPIC9K, downstream of a alpha-factor signal peptide sequence. The resultant recombinant vector was named pM242. After linearized with Sac I , pM242 was transformed to Pichia pastoris GS115 by electroporation. After screening, the recombinant strain Gpmf25 that expresses the secretory protein at high level was obtained. The activity of the recombinant mannanase reached 12.5 IU/mL. Optimum pH and temperature for the recombinant enzyme were 5.0 and 80 degrees C, respectively. The enzyme was stable at pH 5.0-6.0 and maintained over 50% of original activity after incubation at 70 degrees C for 30 min.

[Expression, purification and enzymatic characterization of Bacillus polymyxa beta-glucosidase gene( bglA ) in Escherichia coli].

The beta-glucosidase encoding gene bglA was cloned from Bacillus polymyxa 1.794. The bglA gene was inserted in expression vector pET28a(+) and transformed into Escherichia coli BL21 (DE3), finally the recombinant strain BL1979 was obtained. Induced by IPTG, the expression P-glucosidase activity reached to 24.7 IU/mL. The optimum temperature and optimum pH of the recombinant expression P-glucosidase in BL1979 were 37 degrees C and 7.0 respectively,the purity can reach to 92.7%. Analysis of the fusion protein by nondenaturing gradient gel electrophoresis, we found the fusion protein exists in dimmer, tetramer,hexamer and octamer, they all have hydrolase activity.