Authors:Y. Li, F.Q. Lu, Y. Feng, Z.D. He, and X.L. Wu
Analysis of the binding interaction of (−)-epigallocatechin-3-gallate (EGCG) and pepsin is important for understanding the inhibition of digestive enzymes by tea polyphenols. We studied the binding of EGCG to pepsin using fluorescence spectroscopy, Fourier transform infrared spectroscopy, isothermal titration calorimetry, and protein-ligand docking. We found that EGCG could inhibit pepsin activity. According to thermodynamic parameters, a negative ΔG indicated that the interaction between EGCG and pepsin was spontaneous, and the electrostatic force accompanied by hydrophobic binding forces may play major role in the binding. Data from multi-spectroscopy and docking studies suggest that EGCG could bind pepsin with a change in the native conformation of pepsin. Our results provide further understanding of the nature of the binding interactions between catechins and digestive enzymes.
Authors:X. Li, S. Lan, Y. Zhang, L. Lu, S. Liu, L. Wang, and S. Rajaram
Abiotic stresses like salinity and abnormally cold environments cause significant yield losses in many crops including wheat. Therefore, concerted efforts are being made by breeders to develop new varieties with salt and cold tolerance to ensure stable yields over varied environments. This study was undertaken to screen six hundred and seventy-seven accessions of international wheat genetic resources to identify lines with high level of tolerance to salinity and cold environments. Based on the results of two years study in different agroecological locations, 51 accessions were classified as salt tolerant and 115 accessions were classified as cold tolerant. Of these, 35 accessions had good agronomic characteristics. Also, there were 39 genotypes with combined tolerance to cold as well as salinity. Thus, there were good lines which can be used directly or as parents for breeding wheat varieties for wide adaptation and high yield. Further analysis of the data showed that early genotypes had good cold tolerance but a poor salt tolerance. It was also observed that small number of both test spikelet and spikelet, short spike length and good seed-plump were positively associated with cold tolerance. Therefore, maturity and spike traits should be taken into considered when selecting wheat lines for wide adaptation breeding.
Authors:C. Wang, L. Li, X. Zhang, Q. Gao, R. Wang, and D. An
Molecular markers are important tools that have been used to identify the short arm of rye chromosome 1R (1RS) which contains many useful genes introgressed into wheat background. Wheat expressed sequence tag (EST) sequences are valuable for developing molecular markers since ESTs are derived from gene transcripts and more likely to be conserved between wheat and its relative species. In the present study, 35 sequence-tagged site (STS) primers were designed based on EST sequences distributed on homology group 1 chromosomes of
and used to screen specific markers for chromosome 1RS of
. Two primer pairs different from the early studies, STS
, which amplified a 1680-bp and a 1750-bp fragment, and STS
, which produced a 850-bp fragment from rye genome, were proved to be specific to chromosome 1RS since the corresponding fragments were only amplified from 1R chromosome addition line and wheat-rye lines with chromosome 1RS, but not from wheat-rye 2R-7R chromosome addition lines and the other lines lacking chromosome 1RS. Eleven wheat-rye lines derived from ‘Xiaoyan 6’ and ‘German White’ were used to test the presence of specific markers for 1RS. The specific fragments of 1RS were amplified in 4 wheat-rye lines, but not in the other lines. The testing results using EST-STS markers of 1RS were consistent with those obtained from fluorescence
hybridization (FISH), suggesting that these markers specific to 1RS could be used in marker-assisted selection (MAS) for incorporating 1RS into wheat cultivars in breeding.
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.
Authors:L. Ma, P. Xiao, J. Cai, X. Li, Z. Ji, Y. Xia, C. Yang, and J. Bao
Uniformity in the height of main stem and tillers is a key factor affecting ideal plant type, a key component in super high-yielding rice breeding. An understanding of the genetic basis of the panicle layer uniformity may thus contribute to breeding varieties with good plant type and high yield. In the present study, a doubled haploid (DH) population, derived from a cross between
rice variety Zhai-Ye-Qing 8 (ZYQ8) and
rice variety Jing-Xi 17 (JX17) was used to analyze quantitative trait loci (QTL) for panicle layer uniformity related traits. Six, four and three QTL were detected for the highest panicle height (HPH), lowest panicle height (LPH) and panicle layer dis-uniformity (PLD), respectively. qHPH-1-1 and qPLD-1 were located at the same interval on chromosome 1. The JX17 allele(s) of these QTL increased HPH and PLD by 2.57 and 1.26 cm, respectively. Similarly, qPLD-7 and qHPH-7 were located at the same interval on chromosome 7, where the ZYQ8 allele(s) increased HPH and PLD by 3.74 and 1.96 cm, respectively. These four QTL were unfavourable for panicle layer uniformity improvement because a decrease of the PLD was accompanied by decrease of the plant height. qPLD-6 and qLPH-6-1 were located at the same interval on chromosome 6, however here the JX17 allele(s) increased LPH, but decreased PLD, suggesting that this QTL was favourable for improvement of panicle layer uniformity. The markers identified in this study are potential for marker assisted breeding for the improvement of the panicle layer uniformity and ideal plant type.
Authors:L.H. Feng, Y.Q. Li, G.J. Sun, and X.Z. Zhao
The objective of this work was to research the antibacterial effects of orange pigment, which was separated from Monascus pigments, against Staphylococcus aureus. The increase of the diameter of inhibition zone treated with orange pigment indicated that orange pigment had remarkable antibacterial activities against S. aureus. Orange pigment (10 mg ml−1) had a strong destructive effect on the membrane and structure of S. aureus by the analysis of scanning electron microscopy as well as transmission electron microscopy. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) further demonstrated that the cell membrane was seriously damaged by orange pigment, which resulted in the leakage of protein from S. aureus cells. A significant decrease in the synthesis of DNA was also seen in S. aureus cells exposed to 10 mg ml−1 orange pigment. All in all, orange pigment showed excellent antibacterial effects against S. aureus.
Authors:Q. Li, K. Ji, X. Song, E. Zhang, Y. Pei, and Y. Yan
Gliadins were extracted from three wheat varieties, viz. Nongda 99260037 (good quality), Henan 9023 (media quality) and Nongda 98123 (poor quality), and
α-, β-, γ-, ω
-gliadins were purified from Nongda 99260037 using preparative SDS-PAGE. The total gliadins and
α-, β-, γ-, ω
-gliadins were used as antigens to immunise BALB/C mice, and the corresponding polyclonal antibodies were prepared, designated as Anti-A, Anti-B, Anti-C, Anti-A
, respectively. Binding of the polyclonal antibodies with 8 varieties, that varied in quality properties, showed correlations with some wheat quality parameters. Correlation coefficients between antibodies against total gliadins or
-gliadin of Nongda 99260037 and quality parameters were higher than other antibodies. Of seven polyclonal antibodies tested, three (Anti-A
and Anti-A) displayed significant positive or negative associations between antibody binding and dough development time, strength, valorimenter value and stability time, but no significant correlations were observed with water absorption. These results suggest that polyclonal antibodies could be used for rapid prediction and screening of wheat quality parameters.
Authors:J. Zhou, Z. Yang, J. Feng, X. Zhang, G. Li, and Z. Ren
plays an important role in wheat improvement. Here we report a new triticale, named Fenzhi-1, derived from the wide cross MY11
after the in vitro rye pollen has been irradiated by He-Ne laser. Morphologically, Fenzhi-1 is characterized by branched-spikes. Genetically, Fenzhi-1 displays stable fertility and immunity to wheat powdery mildew and stripe rust. In situ hybridization (FISH) and seed storage protein electrophoresis revealed that Fenzhi-1 is a new primary hexaploid triticale (AABBRR). The present study not only provides a new method to synthesize an artificial species, but also shows that Fenzhi-1 could be a valuable source for wheat improvement.
Authors:W. Dong, W. Li, H. Zhang, X. Wang, Z. You, C. Zhou, J. Du, and Z. Tao
The stability constants for tracer concentrations of Co(II) complexes with the red earth fulvic acid were determined at pH
3.8–6.8 and ionic strength 0.0010–1.0 mol/l by using the cation exchange equilibrium method and the radiotracer60Co. The effects of ionic strength and pH on the stability constants of 1∶1 Co(II) complexes were investigated, and it was
found that the stability constants of complexes of humic substances do not vary with ionic strength and pH in a manner similar
to that of simple complexes.
Authors:J. Du, W. Li, H. Zhang, X. Wang, Z. You, C. Zhou, W. Dong, and Z. Tao
The stability constants for tracer concentrations of Co(II) complexes with both the red earth humic and fulvic acids were
determined at pH 5.9 and ionic strength 0.010 mol/l by using theArdakani-Stevenson cation exchange equilibrium method and the radiotracer60Co. It was found that the 1:1 complexes of Co(II) with the red earth humic and fulvic acids were formed and that the average
values of logβ (stability constant) of humic and fulvic acid complexes were 5.76±0.19 and 4.42±0.03, respectively.