Major QTL for Fusarium crown rot resistance in a barley landrace

Fusarium crown rot (FCR) is a serious cereal disease in semi-arid regions worldwide. In assisting the effort of breeding cultivars with enhanced resistance, we identified several barley genotypes with high levels of FCR resistance. One of these genotypes, AWCS079 which is a barley landrace originating from Japan, was investigated by developing and assessing three populations of recombinant inbred lines. Two QTL, one located on the long arm of chromosome 1H (designated as Qcrs.cpi-1H) and the other on 3HL (designated as Qcrs.cpi-3H), were found to be responsible for the FCR resistance of this genotype. Qcrs.cpi-1H is novel as no other FCR loci have been reported on this chromosome arm. Qcrs.cpi-3H co-located with a reduced height (Rht) locus and the effectiveness of the former was significantly affected by the latter. The total phenotypic variance explained by these two QTL was over 60 %. Significant effects were detected for each of the QTL in each of the three populations assessed. The existence of these loci with major effects should not only facilitate breeding and exploitation of FCR-resistant barley cultivars but also their further characterization based on fine mapping and map-based gene cloning.

Choice of microsatellite markers for identifying homozygosity of mitotic gynogenetic diploids in Japanese flounder Paralichthys olivaceus

A set of 72 microsatellite markers distributed evenly among 24 linkage groups were selected from the published genetic linkage maps of Japanese flounder Paralichthys olivaceus. In two normal diploid full-sib families, the test for Mendelian inheritance showed that genotypic segregation deviations were not significant at all analysed loci. To estimate microsatellite-centromere map distances, four meiotic gynogenetic diploid lines were produced by the activation of eggs using UV irradiated sperm of red seabream Pagrus major and cold-shock treatment to block the extrusion of the second polar body. Under the assumption of complete interference, 21 markers were located in the centromeric region, 39 in the telomeric region and the rest in the intermediate region of linkage groups. A total of 192 mitotic gynogenetic diploids from one spawn were identified by these markers. Genotype analysis showed that the number of homozygous individuals decreased as microsatellite-centromere map distance increased on each linkage group.

Synthesis, structure-activity relationship and in vitro anti-mycobacterial evaluation of 13-n-octylberberine derivatives

Twenty-eight new 13-n-octylberberine derivatives were synthesized and evaluated for their activities against drug-susceptible Mycobacterium tuberculosis (M. tuberculosis) strain H(37)Rv. Among these compounds, compound 16e was the most effective anti-tubercular agent with a MIC value of 0.125 μg/mL. Importantly, compound 16e exhibited more potent effect against rifampicin (RIF)- and isoniazid (INH)-resistant M. tuberculosis strains than both RIF and INH, suggesting a new mechanism of action. Therefore, it has been selected as a drug candidate for further investigation, or as a chemical probe for identifying protein target and studying tuberculosis biology. We consider 13-n-octylberberine analogs to be a promising novel class of antituberculars against multi-drug-resistant (MDR) strains of M. tuberculosis.

Polymorphisms of the ATP1A1 gene associated with mastitis in dairy cattle

Mastitis affects the concentrations of potassium and sodium in milk. Since sodium-potassium adenosine triphosphatase (Na(+), K(+)-ATPase) is critical for maintaining the homeostasis of these two ions, and is involved in cell apoptosis and pathogenesis, we presumed that polymorphism of the ATP1A1 gene, which encodes the bovine Na(+), K(+)-ATPase α1 subunit could be associated with mastitis. The ATP1A1 gene was analyzed in 320 Holstein cows using PCR low ionic strength single-strand conformation polymorphism (PCR-LIS-SSCP) and DNA sequencing methods. A C/A SNP was identified at nucleotide position -15,739 in exon 17 of the ATP1A1 gene, but it did not induce any change in amino acids. We examined a possible association of polymorphism of the ATP1A1 gene with somatic cell score and 305-day milk yields. Individuals with genotype CC in ATP1A1 had significantly lower somatic cell scores and 305-day milk yields than those with genotype CA. We also examined changes in Na(+), K(+)-ATPase activity of red cell membranes. The Na(+), K(+)-ATPase activity was significantly higher in dairy cows with genotype CC compared to the other two genotypes, and the Na(+), K(+)-ATPase activity of the resistant group was significantly higher than that of the susceptible group in dairy cows. We conclude that this polymorphism has potential as a marker for mastitis resistance in dairy cattle.

Detection of the Treponema pallidum gene and variation of treponemal DNA load before and after therapy

We explored a genetic detection method for Treponema pallidum (TP) in the peripheral blood of infected patients to compare the loads of treponemal DNA before and after therapy and to see if this new technique enabled assessment of therapeutic effect and detection of serum resistance. Polymerase chain reaction was used for a qualitative detection of TP DNA in peripheral blood and then a semiquantitative method was adopted to estimate the load of TP DNA in blood, both before and after treatment of syphilis. Among 30 untreated patients, three cases were TP DNA-positive. Among 42 treated patients with demonstrated serum resistance, three cases were TP DNA-positive. Five cases in which the rapid plasma reagin had become negative had no detectable TP DNA in their peripheral blood. The TP DNA load in blood after treatment was significantly lower than that before therapy. We conclude that the detection of TP DNA in peripheral blood of TP-infected patients is not yet sufficiently sensitive, but we observed that TP DNA load declines significantly after treatment.

The effects of Mn2+ doping on the luminescence properties of 12CaO 7Al2O:Eu2+ nanocrystal phosphor

The long lasting blue phosphorescence (LLP) and photostimulated luminescence (PSL) after ultraviolet light irradiation at room temperature in 12CaO 7Al2O3:xEu2+, yMn2+ (x = 0, 0.001; y = 0, 0.01) prepared by the chemical co-precipitation method were observed. It was shown that novel oxide 12CaO 7Al2O3:Eu2+, Mn2+ (C12A7:Eu2+, Mn2+) with unique nanocage structure can store energy when irradiated with 365 nm photons. And photon energy can be subsequently released by exposed to 980 nm light. The codopant Mn2+ enhances the intensity of the persistent phosphorescence and PSL due to the existence of more shallow and new deeper electron traps in C12A7: Eu2+, Mn2+. A model for energy storing and recovering and the detailed mechanism of PSL are presented through comparing with the luminescence properties of the co-doped C12A7:Eu2+, Mn2+ and C12A7:Eu2+.

Characterization and luminescence of Eu3+ ions doped 12CaO 7Al2O3 nanopowders

Eu3+ ions doped 12CaO 7Al2O3 (C12A7) powders with different Eu3+ concentrations were prepared by sol-gel combined with solid state reaction method. The results of XRD and Raman spectra showed that single cubic phase polycrystalline C12A7:Eu3+ powders were prepared. The absorption peaks attributed to f-f transition of Eu3+ ion can be observed, indicating that Eu3+ had been incorporated into C12A7 lattice site. Visible PL peaks around 578, 588, 614 nm were ascribed to 5D0 --> 7FJ (J = 0, 1, 2) transitions of Eu3+ under the excitation of 488 nm line. The PL of C12A7:Eu3+ showed the strongest emission intensity at Eu3+ concentration of 0.5 at%. Two different types of Eu3+ centers were identified by the two lines from 5D0 --> 7F0 transition emission. The doping mechanism of C12A7:Eu3+ might be attributed to Eu3+ ions substitution for two types of Ca2+ lattice sites in C12A7. The temperature dependent PL spectra of Eu-doped C12A7 were measured in the range from 100 to 300 K under the excitation of 488 nm laser line. The PL intensities as a function of temperature were well fitted by using a unified theoretical model, considering thermal activation and nonradiative energy transfer processes.

Visible luminescence mechanism of ZnO nanoparticles synthesized by sol-gel method

We presented our investigations on the absorption and emission properties of the nanocrystalline ZnO particles of different particle sizes (2 nm-5 nm) by sol-gel method. In the room temperature PL spectra, three emission bands, ultraviolet (UV), blue and green were observed. With increasing the particle sizes, both the UV and the visible emission bands shifted to lower energies progressively. From the size-dependency, there was a linear relationship between the energetic maxima of the UV and the green emission bands with a slope of about 0.26, which indicated that the green luminescence of ZnO was produced by the transitions of electrons from deep level to the valence band (or shallow acceptor level). A linear dependence was also found between the energetic maxima of the UV and the blue emissions with a slope of 0.15, the origin this blue emission band is not clear at present. While in van Dijken et al.'s paper, however, they identified only two emission bands in the emission spectra, an UV and a broad visible emission band, and the linear fit between the energetic maxima of these two bands in particles of different sizes has a slope of 0.6, so they proposed that the visible emission in ZnO was originated from the recombination of a shallowly trapped electron with a deeply trapped hole. We attributed this divergence to the fact that the broad visible band is actually composed of two separate emission bands originated from two different recombination processes, and should not had been treated as one emission band.

Luminescence and energy transfer characteristics of Ce3+- and Tb3+-codoped nanoporous 12CaO 7Al2O3 phosphors

The novel green-emitting phosphors of 12CaO 7Al2O3:Ce3+ , Tb3+ (C12A7:Ce3+, Tb3+) were synthesized by a solid-state reaction. Upon the excitation of Ce3+ at 350 nm, the C12A7:Ce3+, Tb3+ phosphor shows intense green emissions located at 543 nm assigning to 5D4-7F5 transitions of Tb3+ ions, and weak blue emissions centered at 434 nm due to the transitions of Ce3+ 5d-4f. The photoluminescence (PL) intensity of Ce3+ decrease with increasing Tb3+ concentration, indicating the effective energy transfer (ET) occurred from Ce3+ to Tb3+ in C12A7:Ce3+, Tb3+. The ET efficiency between Ce3+ and Tb3+ in the optimum composition reaches to 99%. Based on Dexter's ET theory, we have demonstrated that the efficient ET is a resonant type via dipole-dipole mechanism with an energy transfer critical distance of 4.02 A. Our results suggested that C12A7:Ce3+, Tb3+ phosphor would be a promising green-emitting phosphor for UV-converting white light-emitting diodes.

Synthesis, structure-activity relationship and biological evaluation of novel N-substituted matrinic acid derivatives as host heat-stress cognate 70 (Hsc70) down-regulators

Oxymatrine (1) is a natural anti-hepatitis B virus (HBV) drug that down-regulates host heat-stress cognate 70 (Hsc70) expression through a mechanism different from that of nucleosides. Taking Hsc70 as a target against HBV, 26 novel N-substituted matrinic acid analogs were designed, synthesized and evaluated for their regulation of Hsc70 mRNA expression with 1 as the lead. The SAR analysis revealed that (i) the carboxyl group at the 11-position was required for activity; (ii) introducing of a substituent on the nitrogen atom at the 12-position of 3, especially substituted benzyl, might significantly improve the activity. Among these analogs, compound 9p possessing N-p-methoxylbenzyl afforded an increased anti-HBV effect in comparison with 1. We consider 9p a promising anti-HBV candidate.

Plant height affects Fusarium crown rot severity in wheat

Effects of plant height on Fusarium crown rot (FCR) disease severity were investigated using 12 pairs of near-isogenic lines (NILs) for six different reduced height (Rht) genes in wheat. The dwarf isolines all gave better FCR resistance when compared with their respective tall counterparts, although the Rht genes involved in these NILs are located on several different chromosomes. Treating plants with exogenous gibberellin increased FCR severity as well as seedling lengths in all of the isolines tested. Analysis of the expression of several defense genes with known correlation with resistance to FCR pathogens between the Rht isolines following FCR inoculation indicated that the better resistance of the dwarf isolines was not due to enhanced defense gene induction. These results suggested that the difference in FCR severity between the tall and dwarf isolines is likely due to their height difference per se or to some physiological and structural consequences of reduced height. Thus, caution should be taken when considering to exploit any FCR locus located near a height gene.

[Analysis of HSP70 mRNA level and association between linked microsatellite loci and heat tolerance traits in dairy cows]

The objective of this study was to investigate the variation of HSP70 mRNA level in dairy cows and relationships of its closely linked microsatellite loci with heat tolerance traits. Blood samples were collected from ten healthy Holstein cows with the same age and milking stage at different temperatures-humid-index (THI) (86.2, high temperature; 70.9, critical high temperature, and 56.8, optimum temperature). The mRNA levels of HSP70 of lymphocytes in peripheral blood were analyzed using real-time RT-PCR. The mRNA level of HSP70 was increased with the THI; the mRNA level of HSP70 at high temperature was higher than others (P<0.01). This indicated that the bovine HSP70 gene may act as a potential can-didate gene for response to heat shock. Genetic variation of three microsatellite loci BMS468, BM1258, and BM1815, which were closely linked to HSP70 gene on chromosome 23, was analyzed in 160 Holstein cows with non-denaturing poly-acrylamide gel electrophoresis. The association between these microsatellite loci and heat tolerance traits were analyzed by least square linear model. The results showed that 134 bp/128 bp at BMS468 and 186 bp/148 bp at BM1815 were the most favorable genotypes for HTC, red cell potassium, and decrement rate of milk yield in high temperature (P<0.05); 101 bp/99 bp at BM1258 was the most favorable genotype for decrement rate of milk yield in high temperature (P<0.05).

Association of ATP1A1 gene polymorphism with heat tolerance traits in dairy cattle

Heat stress produces oxidative stress and affects the alternation of plasma K(+) and Na(+). Since Na(+),K(+)-ATPase is sensitive to oxidative stress and critical for maintaining the homeostasis of these two ions, we examined the genetic polymorphism of the ATP1A1 gene in 160 Holstein cows using polymerase chain reaction low ionic strength single-strand conformation polymorphism and DNA sequencing methods. G to A at position -14103 in exon 14 and C to T at position -14242 in intron 14 of the bovine ATP1A1 gene were identified, but the former single nucleotide polymorphism was silent with respect to the amino acid sequence of the protein. However, we found significant correlations between ATP1A1 gene polymorphism and the coefficient of heat tolerance (P<0.01) and with respiratory rate (P<0.01). Genotype AC was the most favorable genotype for heat tolerance. This polymorphism site has potential as a genetic marker for heat tolerance traits in dairy cattle breeding.

[Relationships of three microsatellite loci with GSH-Px, SOD and Na+/K+-ATP enzyme activities and daily milk yield in different seasons in Holstein cows]

Genetic variation of three microsatellite loci BMS2258, SOD1, and BM723, which were closely correlated with GSH-Px, SOD, and Na+/K+-ATPase genes, was analyzed in 130 Holstein cows by PCR and nondenaturing polyacrylamide gel-electrophoresis. Polymorphic information content, effective number of alleles and heterozygosity of these microsatellite loci were determined. Relationships of the three microsatellite loci with enzyme activities and daily milk yields in Holstein cows were analyzed by least squares linear model. The results showed significant correlations of the three microsatellite loci with their corresponding enzyme activities and daily milk yield in summer and fall (Plt;0.05). The least square means of GSH-Px activities and daily milk yields for BMS2258 (182 bp/164 bp), SOD activities for SOD1 (148 bp/148 bp), and daily milk yields for SOD1 (148 bp/146 bp), Na+/K+-ATPase activities and daily milk yields for BM723 (161 bp/111 bp) were relatively higher. These genotypes were the most favorable genotypes for enzyme activity and daily milk yields in summer and fall, which could be references for marker assisted selection in heat resistance traits in dairy cattle.

Identification and validation of a major QTL conferring crown rot resistance in hexaploid wheat

Crown rot (CR), caused by various Fusarium species, is a chronic wheat disease in Australia. As part of our objective of improving the efficiency of breeding CR resistant wheat varieties, we have been searching for novel sources of resistance. This paper reports on the genetic control of one of these newly identified resistant genotypes, 'CSCR6'. A population derived from a cross between CSCR6 and an Australian variety 'Lang' was analyzed using two Fusarium isolates belonging to two different species, one Fusarium pseudograminearum and the other Fusarium graminearum. The two isolates detected QTL with the same chromosomal locations and comparable magnitudes, indicating that CR resistance is not species-specific. The resistant allele of one of the QTL was derived from 'CSCR6'. This QTL, designated as Qcrs.cpi-3B, was located on the long arm of chromosome 3B and explains up to 48.8% of the phenotypic variance based on interval mapping analysis. Another QTL, with resistant allele from the variety 'Lang', was located on chromosome 4B. This QTL explained up to 22.8% of the phenotypic variance. A strong interaction between Qcsr.cpi-3B and Qcsr.cpi-4B was detected, reducing the maximum effect of Qcrs.cpi-3B to 43.1%. The effects of Qcrs.cpi-3B were further validated in four additional populations and the presence of this single QTL reduced CR severity by up to 42.1%. The fact that significant effects of Qcrs.cpi-3B were detected across all trials with different genetic backgrounds and with the use of isolates belonging to two different Fusarium species make it an ideal target for breeding programs as well as for further characterization of the gene(s) involved in its resistance.

Characterization and optical transition in tb-doped 12CaO x 7Al2O3 powders

Tb-doped 12CaO x 7Al2O3 (C12A7:Tb3+) powders with strong green emission were prepared using the sol-gel method. X-ray diffraction, micro-Raman spectra, scanning electron microscopy and absorption spectra showed that C12A7:Tb3+ powders with grain size of 200-300 nm were synthesized. Porous powders could be formed as the concentration of Tb3+ was 5 at%. The absorption band around 209 nm was attributed to the host lattice absorption, and the bands around 255 nm and 274 nm were related to the 4f-5d transitions of Tb3+. The absorption intensity of the visible region was enhanced due to the presence of one 100 nm-diameter hole in every grain of C12A7:Tb3+ powders. The emission spectra showed noticeable influence of Tb-Tb cross relaxation, which favored the green photoluminescence (PL) over the blue PL. The study on the concentration quenching indicated that the energy transfers depopulating the 5D3 and 5D4 levels were assigned to the mechanisms of electric dipole-dipole and exchange interaction, respectively.

Probing the visible luminescence mechanism in ZnO nanoparticles by band edge modulation

The visible luminescence mechanism of ZnO is an important but controversial problem. In this paper, we report the structural and optical properties of Mg-doped ZnO nanoparticles (approximately 3-4 nm) synthesized via the sol-gel method. X-ray diffraction (XRD) analysis and absorption spectra observations revealed that Mg ions replace Zn ions in the lattice. In the room temperature photoluminescence (PL) spectra, three emission bands, ultraviolet (UV), blue, and green, were observed. With increasing concentration of Mg, the near band edge (NBE) emission band progressively shifted to the higher energy side. The green emission in the visible emission band, however, presented an inconspicuous shift. The reason is probably that the bottom of the conduction band in ZnO is determined by the Zn 4s state, and the top of the valence band is determined by the O 2p state. Mg ions in ZnO substitute for zinc ions and enter a slightly distorted tetrahedral site, which causes the bottom of the ZnO conduction band to be shifted to higher energy and leaves the top of the valence band unchanged. This combined with the fact that the deep level position is insensitive to the shift of the band edge led us to conclude that the green emission originates from electronic transition between the deep defect level and the top of the valence band (or very shallow acceptor level).

Characterization and water activation behavior of tourmaline nanoparticles

Tourmaline nanoparticles were prepared by using a wet mechanochemisty method. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) results showed that the tourmaline grain size is in the range from tens of nanometers to several hundred nanometers. Through characterization by Fourier transform infrared spectroscope, it was found that the milled tourmaline had a better far infrared emitting performance due to the increase of radiation surface area. The structure change of liquid water clusters induced by the addition of tourmaline nanoparticles was observed by nuclear magnetic resonance (NMR). The results showed that the addition of tourmaline nanoparticles reduced the 17O NMR full width at half maximum intensity (FWHM) for treated water and the volume of water molecule clusters. The feature of activated water was enhanced with decreasing tourmaline nanoparticles size due to the cooperation of strong surface electric field and high far infrared emissivity. Moreover the activation time can be maintained at 480 h suggesting the potential application of tourmaline in wastewater treatment.

Effects of annealing on the ferromagnetism and photoluminescence of Cu-doped ZnO nanowires

Room temperature ferromagnetic Cu-doped ZnO nanowires have been synthesized using the chemical vapor deposition method. By combining structural characterizations and comparative annealing experiments, it has been found that both extrinsic (CuO nanoparticles) and intrinsic (Zn(1-x)Cu(x)O nanowires) sources are responsible for the observed ferromagnetic ordering of the as-grown samples. As regards the former, annealing in Zn vapor led to a dramatic decrease of the ferromagnetism. For the latter, a reversible switching of the ferromagnetism was observed with sequential annealings in Zn vapor and oxygen ambience respectively, which agreed well with previous reports for Cu-doped ZnO films. In addition, we have for the first time observed low temperature photoluminescence changed with magnetic properties upon annealing in different conditions, which revealed the crucial role played by interstitial zinc in directly mediating high T(c) ferromagnetism and indirectly modulating the Cu-related structured green emission via different charge transfer transitions.

Genotyping of hantaviruses occurring in Linyi, China, by nested RT-PCR combined with single-strand conformation polymorphism analysis

The hemorrhagic fever with renal syndrome (HFRS) incidence rate still holds in high level in some areas of the world, but a reliable and simple typing method that can be used in clinical diagnosis and epidemiologic surveys is not available. In this study, 48 serum samples were collected from patients with HFRS in Linyi area, China, that is seriously affected by this disease. The collected samples were analyzed by nested RT-PCR combined with single-strand conformation polymorphism (SSCP) for genotyping of hantaviruses (HV). Out of 48 serum samples, 41 samples were positive by the nested RT-PCR. According to the SSCP patterns, Seoul virus (SEOV) was found in 33 samples and Hantaan virus (HTNV) in 8 samples. The comparison of sequence identities of nested RT-PCR products of tested samples with reference isolates SEOV and HTNV supported the typing results. Thus, genotyping of HV by nested RT-PCR/SSCP is suitable in early diagnosis of HV infection and in epidemiologic surveys.