The calorimetric data of blended shrinkage-compensating binders with different compositions were measured at 25C at different
water-binder ratios using an isothermal calorimeter. The hydration characteristics of shrinkage-compensating binders were
evaluated and their influence on the expansive properties of blended shrinkage-compensating binders was determined. Composition
and w/b ratio significantly affect the hydration rate and degree of shrinkage-compensating binders, as well as their expansive
and mechanical properties. The total heat of hydration of binders decreases with w/c ratios. Its final hydration degree also
decreases with w/c ratio. The ternary binders composed with Portland cement, mineral admixture and expansive agent show low
hydration heat and rate of heat evolution, but their total heat of hydration increases continuously and surpasses that of
binary binder in later period at low w/b ratio.
Authors:X. Geng, M. Zheng, B. Wang, Z. Lei, and X. Geng
Calorimetric measurement of adsorption enthalpies of native lysozyme(Lyz) on a moderately hydrophobic surface at 25°C, pH
7.0 and various salt concentrations was performed. Based on the thermodynamics of stoichiometric displacement theory (SDT),
we calculated the fractions of thermodynamic functions involving four subprocesses during a displacement adsorption process
from the directly determined enthalpies in combination with adsorption isotherm measurements. The thermodynamic fractions
reveal the relative degree of the four subprocesses for contributions to enthalpy, entropy and free energy. The results show
that native Lyz adsorption on a moderately hydrophobic surface is an entropy driven process contributed mainly by conformational
loss of adsorbed Lyz.
Authors:J. Wang, Z. Yan, Y. Zheng, W. Cao, and Y. Wei
Fructose-bisphosphate aldolase (FBA, EC 184.108.40.206) catalyzes an aldol cleavage of fructose-1, 6-bisphosphate to dihydroxyacetone-phosphate and glyceraldehyde 3-phosphate and a reversible aldol condensation. Three candidate genes with 1077bp coding for fructose-bisphosphate aldolase were cloned and sequenced in wheat, barley and rye. These genes could encode 358 amino acid residues. Sequence analysis indicated that wheat, barley and rye FBA genes were conserved with high identity (94.13%), while maize sequence had a 9bp deletion near the 3’ terminal. According to the alignment of 75 amino acid sequences, conserved domains of the FBAs were detected. These conserved domains might be the important functional sites of the FBAs. The cytoplasmic FBAs of wheat, barley and rye were clustered together, and the cluster was close to maize and rice FBAs. Nine peptides of the FBAs and the last amino acid Tyr (necessary for preference for fructose 1,6-bisphosphate over fructose 1-phosphate) were most conserved in plants, animals and algae. Current findings suggested that the FBAs could be divided into three main subgroups: plant cytoplasmic FBA, plant chloroplastic FBA and animal FBA. These results also indicated that the active and binding sites of FBAs had rare variations during the long-term evolution.
Authors:Z. Yan, S. Dai, D. Liu, Y. Wei, and Y. Zheng
A novel HMW-GS of Dx5** with slightly faster migration rate than that of Dx5, was found in a Tibet bread wheat landrace using SDS-PAGE. Moreover, Dx5** is the subunit with the fastest migration rate in
locus. The gene for this subunit was isolated and its sequence was obtained in the present study. This gene was very similar to Dx5 both in nucleotide and deduced amino acid sequence. At the nucleotide sequence level, Dx5** different from Dx5 by the deletion of a 27 bp fragment and two nucleotide replacements at position 353(G/C) and 692(C/G), respectively. At the amino acid sequence level, Dx5** different from Dx5 by the deletion of a hexaploid (LGQGQQ) and a tripeptide (GQQ) repetitive motif and two amino acid replacements at position 118(C/S) and 231(A/G), respectively. These results suggested that the Dx5** was a derivation of Dx5 and was formed by replication slippage. Moreover, the specific cysteine (C) located at the beginning of the repetitive domain of Dx5, which proved to be critical for the end-use quality of wheat flours, was replaced by serine (S) in Dx5**.
Authors:Z. Huang, H. Long, Y. Wei, P. Qi, Z. Yan, and Y. Zheng
The most abundant seed storage proteins of wheat are gliadins and glutenins. Gliadins, including
types, are normally monomeric proteins and account for about 50% of the gluten proteins. In this study, 55 sequences of
-gliadin genes were obtained from species of
section, the deduced B genome donors of wheat. Despite the high sequence similarities to the known
-gliadin genes, extensive variations were also found. Using the extensive sequence information deposited in database and obtained in this study, a comprehensive classification of the
-gliadin multigene families were performed based on the primary structures and phylogenic analysis. All the
-gliadin genes analyzed could be divided into 2 types, which contain 8 and 9 cysteines, respectively. Type I (with 8 cysteines) and type II (with 9 cysteines) are further classified to 7 and 4 groups, respectively, and several subgroups are also identified. The genes derived from A, B and D genomes of common wheat were clustered distinctly, indicating that there was apparent genomic specificity in
-gliadins genes. Besides the high homology between
-gliadin genes from
species and B genome of wheat, some unique groups or subgroups were also identified in
section, suggesting that it could be considered as a valuable source of
-gliadin genes. The comparison of deduced primary structures of each group and/or subgroup was conducted, from which their evolution and quality properties were also speculated.
Authors:L. Zhang, Z. Yan, S. Dai, Q. Chen, Z. Yuan, Y. Zheng, and D. Liu
Two experiments to investigate the crossability of
are described. In the first experiment, 372 wide hybridization combinations were done by crossing 196
lines belonging to seven subspecies with 13
accessions. Without embryo rescue and hormone treatment, from the 66220 florets pollinated, 3713 seeds were obtained, with a mean crossability percentages of 5.61% which ranged from 0 to 75%. A lot of hybrid seeds could germinate and produce plants. Out of 372 combinations, 73.12% showed a very low crossability less than 5%, 23.39% showed the crossability of 5–30%, 2.69% showed the crossability of 30–50%, 0.81% showed high crossability more than 50%, respectively. Among the seven
subspecies, there were significant differences in crossability. The ssp.
showed the highest crossability, while polonicum the lowest. All the crossability percentages more than 30% were obtained from the crossing of ssp.
.In the second experiment, the genetics of crossability was investigated using
cultivar Langdon and the D-genome disomic substitution lines of Langdon. Compared with the control Langdon, lines 7D(7A) and 4D(4B) showed higher crossability, which suggested that chromosomes 7A and 4B of tetraploid wheat cv. Langdon carried dominant alleles inhibiting crossability with
. The relationships of present results with previously reported crossability genes of wheat are discussed.
Authors:Z. Yan, Z. Guo, D. Liu, S. Dai, Y. Wei, and Y. Zheng
is the generally accepted D genome diploid donor of hexaploid wheat. The significance of
HMW-GS genes on bread-making properties of bread wheat has been well documented. Among them,
was thought as the pair with potentially value in endowing synthetic hexaploid wheat with good end-use qualities. In this paper, we isolated and sequenced genes Dx5
accession As63. Amino acid sequence comparison indicated that Dy12
is more similar to Dy10 rather than Dy12 of bread wheat. The sequence of Dx5
accession As63 showed higher similarity to that of Dx5 in bread wheat than others. However, it is notable that Dx5
lacked the additional cysteine residue in Dx5, which is responsible for good bread-making quality in common wheat. Moreover, compared to Dx5, Dx5
has an extra hexpeptide repetitive motif unit (SGQGQQ) as well as five amino acid substitutions.
Authors:Y. Zhang, W. Zheng, Q.C. Ying, L.-E. Shi, Z.-L. Zhang, M.-Z. Shi, and Z.-X. Tang
The sub-acute toxicity of E. faecalis HZNU P2 was investigated in rats fed with different doses for 14 days. To evaluate the acute oral toxicity of E. faecalis HZNU P2, rats were fed with E. faecalis HZNU P2 at a high dose of 2×1011 CFU kg−1 for 10 days. Results showed that there were no abnormal clinical signs in any of the groups during the experiment. There were no significant differences in live weight gain among rats fed with E. faecalis HZNU P2, compared to those in control group. Macroscopic or microscopic examinations of organs revealed no abnormalities, indicating that E. faecalis HZNU P2 did not adversely affect the health of rats. Results of this study demonstrated that digestion of E. faecalis HZNU P2 in rats did not show any obvious signs of toxicity.
Authors:W. J. Duan, Z. J. Zheng, Y. L. Geng, J. H. Liu, and X. Wang
A preparative high-speed countercurrent chromatograph (HSCCC) method for the isolation and purification of C6-C2 natural alcohol and benzyl ethanol from Forsythia suspensa was successfully established. Cornoside, forsythenside F, forsythiaside, and acteoside were rapidly obtained for the first time by HSCCC with a two-phase solvent system ethyl acetate-n-butanol-methanol-water (5:1:0.5:5, υ/υ) in one-step separation. The purities of them were all above 97% as determined by high-performance liquid chromatography, and the combination of ESI-MS and NMR analysis confirmed the chemical structures of the four compounds.
Authors:J. Ji, J. Wang, Q. Zheng, J. Li, Z. Wang, X. Zhang, and A. Zhang
The introgressed alien chromosome in BC
progeny of the cross between common wheat (
Agropyron elongatum (Host) (2n=7X=70)
(Popd.) Barkworth & D.R. Dewey] was determined by genomic
hybridization (GISH), fluorescence
hybridization (FISH), using genomic DNA from
as a probe in GISH and repeat sequence pAs1, pSc119.2 as probes in FISH, and molecular marker techniques. The results revealed that the line was a chromosome additional line in which a pair of the chromosomes added was composed of chromosome segment from E-genome of
and short arm of 5B of common wheat cultivar Gao 38 identified by E-genome-specific primers. Powdery mildew test showed the line was highly resistant to powdery mildew as its
parent and this indicated that the gene of resistant to powdery mildew might come from
and localized on E-genome.