Triticum dicoccoides, wild emmer wheat, is the direct progenitor of cultivated wheats, has the same genome formula as durum wheat, and has contributed two genomes to bread wheat. It harbors many useful genes, more than can be used for wheat improvement. These genes are associated with many agronomic traits, abiotic stress tolerances, biotic stress resistances, grain protein content and micronutrient mineral concentrations. In this review, we summarized the achievements regarding gene discovery, i.e. gene identification, mapping and cloning in wild emmer wheat. These genes, controlling important agronomic traits, disease resistance, drought tolerance, high protein content and micronutrient mineral content, should be very useful for improvement of wheat production and food nutrition. However, the majority of genetic resources in wild emmer remain untapped, demonstrating the need for further exploration and utilization for wheat breeding programs. The large number of molecular markers, genomics tools and efficient cloning techniques available for wheat will greatly accelerate the application of wild emmer germplasm to wheat improvement and ensure sustainability of global wheat production.
The bread wheat germplasm comprising of 222 accessions was evaluated for tolerance to Sitobion avenae. A 1000-kernel weight loss rate and an unbiased test of the tolerance were used to quantify tolerance trait. The population structure analysis revealed three subpopulations in this wheat collection. After 103 SSR loci which evenly covered all wheat chromosomes were scanned for association, eight SSR loci significantly associated with S. avenae tolerance. The information reported in this study would be helpful for wise utilization of the S. avenae tolerant germplasm and selection of parental lines in wheat breeding programs.
Authors:S. Elfatih, Y. Peng, J. Ma, J. Peng, D. Sun and W. Ma
A total of 232 accessions of tetraploid species, durum wheat (Triticum turgidum L. ssp. durum Desf., 2n=4x=28, AABB) with a widespread origin of various countries were used in this study. Their high molecular weight glutenin subunit (HMW-GS) composition was identified by Matrix-assisted laser desorption/ionization time-of-flight Mass Spectrometry (MALDI-TOF-MS). Among all accessions analyzed, 194 were homogeneous for HMW-GS, 38 were heterogeneous, and 62 possessed unusual or new subunits. The results revealed a total of 43 alleles, including 5 at Glu-A1 and 38 at Glu-B1, resulting in 60 different allele combinations. The Glu-B1 locus displayed higher variation compared with Glu-A1. Glu-A1c (55.2%) and Glu-B1aj (17.7%) were the most frequent alleles at Glu-A1 and Glu-B1, respectively. Two allele types (“null” and 1) at the Glu-A1 locus and three allele types (7OE + 8, 14+15, 8) at the Glu-B1 locus appeared to be the common types in the 232 accessions. A total of 23 new alleles represented by unusual subunits were detected at the Glu-A1 and the Glu-B1 locus.
Authors:X. Feng, X. Geng, J. Peng, H. Hou and Q. Bai
The displacement adsorption enthalpies (ΔH) of denatured α-Amylase (by 1.8 mol L−1 GuHCl) adsorbed onto a moderately hydrophobic surface (PEG-600, the end-group of polyethylene glycol) from solutions (x mol L−1 (NH4)2SO4, 0.05 mol L−1 KH2PO4, pH 7.0) at 298 K are determined by microcalorimeter. Further, entropies (ΔS), Gibbs free energies (ΔG) and the fractions of ΔH, ΔS, and ΔG for net adsorption of protein and net desorption of water are calculated in combination with adsorption isotherms of α-Amylase
based on the stoichiometric displacement theory for adsorption (SDT-A) and its thermodynamics. It is found that the displacement
adsorptions of denatured α-Amylase onto PEG-600 surface are exothermic and enthalpy driven processes, and the processes of
protein adsorption are accompanied with the hydration by which hydrogen bond form between the adsorbed protein molecules favor
formation of β-sheet and β-turn structures. The Fourier transformation infrared spectroscopy (FTIR) analysis shows that the
contents of ordered secondary structures of adsorbed α-Amylase increase with surface coverages and salt concentrations increment.
Many investigations and researches studied the reaction
ability between high explosive RDX and RDX with other chemicals. However,
accidents still occur and operating problems exist among the RDX manufacturing
process. This study utilized inherent safety concepts and DSC thermal analysis
to assess the incompatible reaction hazards of RDX during usage, handling,
storage, transporting and manufacturing. This assessment includes thermal
curve observations and kinetic evaluations. A decomposition mechanism of the
incompatible reaction is proposed. Among all the contaminants evaluated in
this study, the existence of ferrous chloride tetrahydrate, ferric chloride
hexahydrate and nitric acid shifted the main endothermic and exothermic reactions
of RDX. These contaminants further advanced the exothermic temperature onset
average by about 53, 46 and 61C, respectively. The summarized results
suggest that ferric oxide, ferrous chloride tetrahydrate, ferric chloride
hexahydrate, acetone solution and nitric acid can influence the reaction and
thermokinetic properties of RDX. These chemicals could induce potential hazards
by causing temperature control instability, heating and cooling systems failure,
and produce an unexpected secondary explosion. According to the conclusions
of this study, potential incompatible RDX hazards during usage and manufacturing
could be avoided.
Authors:J.-J. Peng, S.-H. Wu, H.-Y. Hou, C.-P. Lin and C.-M. Shu
Over 90% of the cumene hydroperoxide (CHP) produced in the world is applied in the production of phenol and acetone. The additional
applications were used as a catalyst, a curing agent, and as an initiator for polymerization. Many previous studies from open
literature have verified and employed various aspects of the thermal decomposition and thermokinetics of CHP reactions. An
isothermal microcalorimeter (thermal activity monitor III, TAM III), and a thermal dynamic calorimetry (differential scanning
calorimetry, DSC) were used to resolve the exothermic behaviors, such as exothermic onset temperature (T0), heat power, heat of decomposition (ΔHd), self-heating rate, peak temperature of reaction system, time to maximum rate (TMR), etc. Furthermore, Fourier transform
infrared (FT-IR) spectrometry was used to analyze the CHP products with its derivatives at 150 °C. This study will assess
and validate the thermal hazards of CHP and incompatible reactions of CHP mixed with its derivatives, such as acetonphenone
(AP), and dimethylphenyl carbinol (DMPC), that are essential to process safety design.
Authors:N. Kopelev, V. Chechersky, A. Nath, B. O, M. Larkin, J. Markert, J. Peng and R. Greene
The as-prepared electron-doped system Nd2–xCexCuO4 (where x0.16) is not superconducting. It becomes superconducting only after removal of a minuscule amount of extraneous oxygen (0.02 of O per unit formula). Mössbauer effect studies were carried out for oxygenated and deoxygenated Nd2–xCexCu(57Co)O4 with x=0.14, 0.16, and 0.18. The spectra show evidence of oxygen anions attaching to the probe57Co in apical positions, to form 5- and 6-coordinated species. A conventional procedure for deoxygenation brings about little change in the Mössbauer spectra both above and below the optimal superconducting concentration; however, for x=0.16, a dramatic change is observed—a major fraction of the magnetically split five-coordinated species manifests itself as a paramagnetically relaxed doublet upon deoxygenation, which costitutes a microscopic measure of the superconducting volume fraction. This apparently anomalous behavior at x0.16, where the extraneous oxygen is more readily desorbed, may be related to an electronic and/or local structural change in the CuO2 plane.
Authors:Y. Feng, S. Zhang, X. Peng, J. Yuan, Y. Yang, H. Zhan and Y. Gong
In mammals, testis development is initiated by the expression of the sex-determining gene,
, where-as the genetic trigger for sex determination in birds remains unknown. In the present study, the expression of seven genes implicated in vertebrate sex determination and differentiation were studied in chicken embryonic gonads from day 4 to day 12 of incubation using reverse transcription and the polymerase chain reaction (RT-PCR). Results showed transcription of c
were sexually dimorphic during chicken gonadal development, whereas c
were expressed at similar levels in both sexes. Results of comparative studies between mammals and chickens show that vertebrate sex-determining pathways comprise both conserved and divergent elements: expression profiles of c
are similar to those in mammals, while others appear some differences. Possible functions of these genes on chicken gonadal development were analyzed based on their expression profiles.
Authors:Q. Xu, W.J. Feng, H.R. Peng, Z.F. Ni and Q.X. Sun
Members of WRKY gene family encode transcription factors involved in plant developmental processes and response to biotic and abiotic stresses. In order to understand the function of the TaWRKY71 gene, a homologue gene was isolated and characterised in wheat (Triticum aestivum L.) genotype TAM107. Tissue-specific gene expression profiles indicated that TaWRKY71 was constitutively expressed in roots, stems, leaves, stamen and pistil. The relative expression of TaWRKY71 was elucidated under ABA treatment and other abiotic stresses. In agreement with this, several putative cis-acting elements involved in ABA-response, drought-inducibility, low-temperature and heat response were detected in the promoter region of TaWRKY71. The function of TaWRKY71 was further determined by transforming Arabidopsis thaliana. Transgenic plants over-expressing TaWRKY71 displayed enhanced seed germination under ABA treatment and were tolerant to salt and drought stresses. These results indicate that TaWRKY71 gene might play important roles in seed germination and abiotic stress response.
Authors:J. Zhao, L. Zhong, L. Zou, C. Zhang, L. Peng, W. Xiao and G. Zhao
The purpose of this study was to investigate the effects of endophytic fungi from tartary buckwheat on the host sprout growth and functional metabolite production. Without obvious changes in the appearance of the sprouts, the exogenous fungal mycelia elicitors notably stimulated the sprout growth and rutin accumulation, and the stimulation effect was mainly depended on the mycelia elicitor species along with its treatment dose. Three endophytic fungi Fat6 (Bionectria pityrodes), Fat9 (Fusarium oxysporum) and Fat15 (Alternaria sp.) were screened to be the most effective candidates for promoting F. tataricum sprout growth and rutin production. With application of polysaccharide (PS, 150 mg/l) of endophyte Fat6, PS (200 mg/l) of endophyte Fat9, and PS (150 mg/l) of endophyte Fat15, the rutin yield was effectively increased to 47.89 mg/(100 sprouts), 45.85 mg/(100 sprouts) and 46.83 mg/(100 sprouts), respectively. That was about 1.5- to 1.6-fold compared to the control culture of 29.37 mg/(100 sprouts). Furthermore, the present study revealed that the biosynthesis of the functional flavonoid resulted from the stimulation of the phenylpropanoid pathway by mycelia polysaccharide treatments. Application of specific fungal elicitors could be an efficient strategy for improving the nutritional and functional quality of tartary buckwheat sprouts.