Authors:J. Zhang, J. Zeng, Y. Liu, L. Sun, F. Xu, W. You, and Y. Sawada
Pb(1,4-BDC)·(DMF)(H2O) (1,4-BDC=1,4-benzenedicarboxylate; DMF=dimethylformamide) has been synthesized and investigated by elemental analysis,
FTIR spectroscopy, thermogravimetry (TG), derivative thermogravimetry (DTG). TG-DTG curves show that the thermal decomposition
occurs in four stages and the corresponding apparent activation energies were calculated with the Ozawa-Flynn-Wall (OFW) and
the Friedman methods. The most probable kinetic model function of the dehydration reaction of the compound has been estimated
by the Coats-Redfern integral and the Achar-Bridly-Sharp differential methods in this study.
Authors:J. Zhang, Y. Liu, J. Zeng, F. Xu, L. Sun, W. You, and Y. Sawada
Zinc formate dihydrate has been synthesized and characterized by powder X-ray diffraction, elemental analysis, FTIR spectra
and thermal analysis. The molar heat capacity of the coordination compound was measured by a temperature modulated differential
scanning calorimetry (TMDSC) over the temperature range from 200 to 330 K for the first time. The thermodynamic parameters
such as entropy and enthalpy vs. 298.15 K based on the above molar heat capacity were calculated. The thermal decomposition characteristics of this compound
were investigated by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). TG curve showed that the
thermal decomposition occurred in two stages. The first step was the dehydration process of the coordination compound, and
the second step corresponded to the decomposition of the anhydrous zinc formate. The apparent activation energy of the dehydration
step of the compound was calculated by the Kissinger method using experimental data of TG analysis. There are three sharply
endothermic peaks in the temperature range from 300 to 650 K in DSC curve.
Authors:Z. Ren, W. Liu, Y. Hou, Y. Zhu, L. Chang, and D. Ma
Thermogravimetry (TG) was employed to study the thermal degradation kinetics of poly(etherketone/sulfone)ethylimide (PEK-IE and PES-IE). The corresponding decomposition activation energies and reaction orders were obtained and the comparison was made with their parent polymerspoly(ether-ketone/sulfone) with Cardo group (PEK-C and PES-C). The results show that the degradation activation energies of PEK-IE and PES-IE were lower than that of PEK-C and PES-C; and two stages of the degradation process were found for all the four polymers. For PEK-IE and PES-IE, the activation energies in the first decomposition stage are much lower than that in the second stage and the two stages can be taken as slow induction and fast degradation, whereas for PEK-C and PES-C the activation energies in the first decomposition stage are larger than that in the second stage, and the two stages can both be taken as two fast degradation stages. The decomposition mechanism of the two stages was also speculated.
Authors:L. Wei, S.G. Bai, X.J. Hou, J.M. Li, B. Zhang, W.J. Chen, D.C. Liu, B.L. Liu, and H.G. Zhang
Among 20 awnless Tibetan wheat cultivars analyzed by SDS-PAGE, the migration rate of an HMW-GS in XM001584 and XM001593, named 1BX23*. was shown to be slightly faster than 1Bx6. and slower than Bx7. Its nucleotide sequence was isolated based on homology clones. In a phylogenetic tree of 1Bx genes, 1Bx23* was apparently clustered with 1Bx23. Compared with 1Bx23. eight single nucleotide replacements caused four single amino acid replacements in 1Bx23*. The deletion of “G” at base pair 1463 and insertion of “A” at 1509 bps induced a 42-nucleotide frame shift. “GQRQQAGQWQRPGQ” was replaced by “DKGNRQDNGNDRDK”. The new segment cannot be found in other HMW-GSs, and it is very similar to a segment found in collagen. Moreover, an 18-nucleotide deletion made 1Bx23* six amino acids shorter than 1Bx23. The cultivar XM001593 had 28 chromosomes, which signifies that it was tetraploid wheat, and that the new HMW-GS 1Bx23* cannot be used directly for breeding in common wheat.
Authors:Z.L. Li, H.Y. Li, G. Chen, X.J. Liu, C.L. Kou, S.Z. Ning, Z.W. Yuan, M. Hao, D.C. Liu, and L.Q. Zhang
Seven Glu-A1m allelic variants of the Glu-A1mx genes in Triticum monococcum ssp. monococcum, designated as 1Ax2.1a, 1Ax2.1b, 1Ax2.1c, 1Ax2.1d, 1Ax2.1e, 1Ax2.1f, and 1Ax2.1g were characterized. Their authenticity was confirmed by successful expression of the coding regions in E. coli, and except for the 1Ax2.1a with the presence of internal stop codons at position of 313 aa, all correspond to the subunit in seeds. However, all the active six genes had a same DNA size although their encoding subunits showed different molecular weight. Our study indicated that amino acid residue substitutions rather than previously frequently reported insertions/deletions played an important role on the subunit evolution of these Glu-A1mx alleles. Since variation in the Glu-A1x locus in common wheat is rare, these novel genes at the Glu-A1mx can be used as candidate genes for further wheat quality improvement.
Authors:J.Q. Xu, L. Wang, B.L. Liu, T.F. Xia, D.C. Liu, X. Chang, T.W. Zhang, H.G. Zhang, and Y.H. Shen
As one of the world’s earliest domesticated crops, barley is a model species for the study of evolution and domestication. Domestication is an evolutionary process whereby a population adapts, through selection; to new environments created by human cultivation. We describe the genome-scanning of molecular diversity to assess the evolution of barley in the Tibetan Plateau. We used 667 Diversity Arrays Technology (DArT) markers to genotype 185 barley landraces and wild barley accessions from the Tibetan Plateau. Genetic diversity in wild barley was greater than in landraces at both genome and chromosome levels, except for chromosome 3H. Landraces and wild barley accessions were clearly differentiated genetically, but a limited degree of introgression was still evident. Significant differences in diversity between barley subspecies at the chromosome level were observed for genes known to be related to physiological and phenotypical traits, disease resistance, abiotic stress tolerance, malting quality and agronomic traits. Selection on the genome of six-rowed naked barley has shown clear multiple targets related to both its specific end-use and the extreme environment in Tibet. Our data provide a platform to identify the genes and genetic mechanisms that underlie phenotypic changes, and provide lists of candidate domestication genes for modified breeding strategies.
Authors:Y.Q. Wang, X.J. Hou, B. Zhang, W.J. Chen, D.C. Liu, B.L. Liu, and H.G. Zhang
Red coleoptile is an easily observed agronomic trait of wheat and has been extensively studied. However, the molecular mechanism of this trait has not yet been revealed. In this study, the MYB gene TaMYB-D1 was isolated from the wheat cultivar ‘Gy115’, which possesses red coleoptiles. This gene resided at the short arm of the homoelogous group 7 chromosomes. TaMYB-D1 was the only gene expressed in the coleoptiles of ‘Gy115’ and was not expressed in ‘Opata’ and ‘CS’, which have uncoloured coleoptiles. Phylogenetic analysis placed TaMYB-D1 very close to ZmC1 and other MYB proteins regulating anthocyanin biosynthesis. The encoded protein of TaMYB-D1 had an integrated DNA binding domain of 102 amino acids and a transcription domain with 42 amino acids, similar to the structure of ZmC1. Transient expression analysis in onion epidermal cells showed that TaMYB-D1 was located at the plant nucleus, which suggested its role as a transcription factor. The expression of TaMYB-D1 was accompanied with the expression of TaDFR and anthocyanin biosynthesis in the development of the coleoptile of ‘Gy115’. Transient expression analysis showed that only TaMYB-D1 induced a few ‘Opata’ coleoptile cells to synthesize anthocyanin in light, and the gene also induced a colour change to red in many cells with the help of ZmR. All of these results suggested TaMYB-D1 as the candidate gene for the red coleoptile trait of ‘Gy115’.
Authors:J.W Guo, Q. Li, W.Q. Chen, X. Li, L.Q. Li, T.G. Liu, Z.L. Ren, and P.G. Luo
Leaf senescence is a notably important trait that limits the yield and biomass accumulation of agronomic crops. Therefore, determining the chromosomal position of the expression sequence tags (ESTs) that are associated with leaf senescence is notably interesting in the manipulation of leaf senescence for crop improvement. A total of 32 ESTs that were previously identified during the delaying leaf senescence stage in the stay-green wheat cultivar CN17 were mapped to 42 chromosomes, a chloroplast, a mitochondrion, and a ribosome using in silico mapping. Then, we developed 19 pairs of primers based on these sequences and used them to determine the polymorphisms between the stay-green cultivars (CN12, CN17, and CN18) and the control cultivar MY11. Among the 19 pairs of primers, 5 pairs produced polymorphisms between the stay-green cultivar and the non-stay-green control. Further studies of Chinese Spring nullisomic-tetrasomics show that JK738991 is mapped to 3B, JK738983 is mapped to 5D, and JK738989 is mapped to 2A, 4A, and 3D. The other two ESTs, JK738994 and JK739003, were not assigned to a chromosome using the Chinese Spring nullisomic-tetrasomics, which indicates that these ESTs may be derived from rye DNA in the wide cross. In particular, the ESTs that produce polymorphisms are notably useful in identifying the stay-green cultivar using molecular marker-assisted selection. The results also suggest that the in silico mapping data, even from a comparison genomic analysis based on the homogeneous comparison, are useful at some points, but the data were not always reliable, which requires further investigation using experimental methods.
Authors:W. Xiong, R.Q. Yan, Y.N. Liu, S.W. Peng, Z.Z. Jiang, X. Chai, A.D. Qi, and Y.F. Wang
Compound danshen preparations (CDPs) are used clinically for the treatment of cardiovascular and cerebrovascular diseases. By using the quantitative analysis of multi-components by single-marker (QAMS) method, sixteen compounds (danshensu, protocatechuic acid, protocatechuicaldehyde, caffeic acid, rosmarinic acid, lithospermic acid, notoginsenoside R1, salvianolic acid B, ginsenoside Rg1, ginsenoside Re, salvianolic acid A, salvianolic acid C, ginsenoside Rb1, ginsenoside Rd, cryptotanshinone, and tanshinone IIA were quantified on an ACQUITY ultraperformance liquid chromatography (UPLC) HSS T3 column (2.1 × 100 mm, 1.8 μm) with the mobile phase consisting of 0.1% formic acid aqueous solution (A) and acetonitrile (B) using a gradient elution at the flow rate of 0.30 mL/min in 30 min at 30°C, which was also validated by UPLC-diode array detection (DAD) and UPLC-electrospray ionization multistage/mass spectrometry (ESI-MS/MS) for assuring the feasibility and accuracy. Tested by robustness experiment under slightly changeable conditions, the stability of relative correction factor (RCF) proved to be stable, with RSDs below 5.69%, except for notoginsenoside R1 with relative standard deviation (RSD) 7.83%. This reliable and convenient QAMS method resolved the problem of standard substance insufficiency and improved the quality assessment of preparations consisting of complex compounds with different chemical structures, such as CDPs.
Authors:N. Li, Z. Yu, L. Wang, Y. Zheng, J. Jia, Q. Wang, M. Zhu, X. Liu, X. Xia, and W. Li
The aim of this study was to investigate the effects of maternal lead exposure on the learning and memory ability and expression of tau protein phosphorylation (P-tau) and beta amyloid protein (Aβ) in hippocampus of mice offspring. Pb exposure initiated from beginning of gestation to weaning. Pb acetate administered in drinking solutions was dissolved in distilled deionized water at the concentrations of 0.1%, 0.5% and 1% groups. On the 21
of postnatal day, the learning and memory ability of the mouse pups was tested by Water Maze test and the Pb levels in blood and hippocampus of the offspring were also determined. The expression of P-tau and Aβ in hippocampus was measured by immunohistochemistry and Western blotting. The Pb levels in blood and hippocampus of all exposure groups were significantly higher than that of the control group (
< 0.05). In Water Maze test, the performances of 0.5% and 1% groups were worse than that of the control group (
< 0.05). The expression of P-tau and Aβ was increased in Pb exposed groups than that of the control group (
< 0.05). Tau hyper-phosphorylation and Aβ increase in the hippocampus of pups may contribute to the impairment of learning and memory associated with maternal Pb exposure.