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Powdery mildew (PM) is one of the major fungal diseases and can cause severe damage to pumpkin (Cucurbita moschata) crops worldwide. The causative agent of pumpkin PM is Podosphaera xanthii, a biotrophic fungus. To identify PM-related genes in pumpkin seedlings, cDNA representational difference analysis was previously performed using a RNA-seq method. One of the genes cloned from the transcriptome is homologous to pumpkin MYBR1-like gene encoding the R1-type MYB-like transcription factor. Here, we characterized this MYBR1-like homolog (named CmMYB1) from pumpkin and investigated its role in biotic stresses. The expression of CmMYB1 in resistant pumpkin seedlings was dramatically induced by PM spores inoculation at the early infection stage (before 48 h), and was suppressed by exogenously sprayed hydrogen peroxide, hormones treatments (salicylic acid, abscisic acid, methyl jasmonate, ethephon), and salt stress using quantitative RT-PCR. Constitutive overexpression of CmMYB1 in tobacco slightly aggravated the visible mildew symptoms of leaves, H2O2 accumulation and cell necrosis in seedlings inoculated with PM pathogens. Furthermore, the expression of NPR1 and PDF1.2 in the transgenic plants was lower than that in the wild-type plants. On the other hand, following inoculations with bacterial wilt and scab pathogens, the concentrations of bacterial pathogens near the infection sites were higher in the transgenic lines than in the wild-type plants, respectively. In conclusions, overexpression of CmMYB1 in tobacco displayed increased susceptibility to PM, bacterial wilt and scab. CmMYB1 transgenic tobacco may reduce stress resistance by downregulating hormone-mediated defense genes to aggravate the leaf damage caused by PM. CmMYB1 may play negative roles in biotic stresses in tobacco. [ABSTRACT FROM AUTHOR]

Milk fat determines the quality of milk and is also a main targeted trait in dairy cow breeding. Recent studies have revealed important regulatory roles of microRNAs (miRNA) in milk fat synthesis in the mammary gland. However, the role of miRNA in bovine mammary epithelial cells (BMEC) remains largely unknown. In this study, we found that the overexpression of miR-130a significantly decreased cellular triacylglycerol (TAG) levels and suppressed lipid droplet formation, whereas the inhibition of miR-130a resulted in greater lipid droplet formation and TAG accumulation in BMEC. MiR-130a also significantly affected mRNA expression related to milk fat metabolism. Specifically, the overexpression of miR-130a reduced the mRNA expression of PPARG, FABP3, PLIN2, and FATP1, whereas the downregulation of miR-130a increased the mRNA expression of PPARG, C/EBPβ, C/EBPα, PLIN2, FABP3, and FATP1. Furthermore, western blot analysis revealed the protein level of PPARG in miR-130a mimic and inhibitor transfection groups to be consistent with the mRNA expression response. Finally, luciferase reporter assays verified that PPARG was the direct target of miR-130a. This study provides the first experimental evidence that miR-130a directly affects TAG synthesis in BMEC by targeting PPARG, suggesting that miR-130a potentially could be used to improve beneficial milk components in dairy cows. [ABSTRACT FROM AUTHOR]

Tuwan aduwa was prepared from foxtail millet flours (FMF) and desert date aqueous extract (DDE). FMF were first tested for some functional properties. Tuwan aduwa samples were evaluated for bitterness, colour, softness, flavour and overall acceptability using a 5 point Hedonic scale. Variations in swelling and water holding capacity (WHC) of FMF were lower than the moist heat treated flour samples (FMFH) contrary to oil absorption capacity (OAC); and flour yellowish reduced significantly after heat treatment. Hardness test showed that Tuwan aduwa (M222) prepared with 1:1:1 (v/v/w) water/DDE/FMF was consistently softer than the M333 prepared with ratio 2:1 (DDE/FMF, v/w) and the control C111 made with FMF and water alone. Sensory evaluation revealed that C111 scored the highest in overall liking as indicated by hedonic ratings. These results suggested that use of DDE have significantly (p<0.05) affected the texture, taste and colour of the Tuwan aduwa. [ABSTRACT FROM AUTHOR]

Structures and stabilities of clusters have been systematically studied via using density functional theory (DFT) with generalized gradient approximation (GGA). The calculations show that the stable configurations of are such structures with one N atom bonded to the external of the basic constructions consisting of Os atoms. Meanwhile, clusters represent 'magic number' effect, and 8 is the magic number. Additionally, the ground-state structures of clusters have the best stability, while that of cluster possesses the worst stability. The result of the study on the ionization potential (IP) and the electron affinity (EA) shows that there are not topological differences among the configurations of clusters. [ABSTRACT FROM AUTHOR]

Polypropylene/metallocene polyethylene (PP/mPE) thermoplastic elastomer nanocomposites were prepared by a melt blending process. Metallocene polyethylenes grafted with vinyltriethoxy silane (mPE-g-silane) and neat mPE, both premixed with commercial organoclay (20A) to serve as the elastomer domains, were compared to investigate the silane curing effect on the prepared nanocomposites. According to X-ray diffraction and transmission electron microscopy analyses, the mPE-g-silane was of help in facilitating the intercalation and partial exfoliation of clay for PP/mPE-g-silane/clay system. A slight melting temperature depression of mPE and its nanocomposites was observed with the introduction of the silane curing due to the induced imperfect crystals. There was no silane curing effect found on the thermal stability, but the incorporation of clay increased the thermal stabilities. The PP/mPE-g-silane/clay system conferred higher tensile strength and tear strength than that of PP/mPE/clay system, mainly attributed to the better dispersion in the case of PP/mPE-g-silane. In general, the addition of clay gave more positive enhancement to the tensile and tear properties of the PP/mPE-g-silane/clay system in comparison with the PP/mPE/clay system. [ABSTRACT FROM AUTHOR]

Taxus cuspidata var. nana is a cultivated variety of Taxus cuspidata and contains taxol, a valuable secondary metabolite of medical importance, both in their stems and leaves. In this paper, random amplified polymorphic DNA (RAPD) markers were used to assess the genomic diversity of individual plants within T. cuspidata population. Seventy-four randomly selected plants were analyzed by 29 selected primers among which 25 primers produced polymorphic banding patterns. The coefficient of similarity among the plants ranged from 0.30 to 1.00 with a mean of 0.605. Our results showed that a surprisingly high level of genomic diversity existed within T. cuspidata, and RAPD markers were effective in revealing the diversity. Cluster analysis divided the plants into two groups. This data, when taken together with earlier findings showing variation in taxol content within a natural population of T. cuspidata, suggests a tantalizing possibility for selecting genomically homogeneous T. cuspidata plant lines with elevated and stable taxol content. [ABSTRACT FROM AUTHOR]

A three-dimensional representative volume-element model is presented to study the micromechanical behavior of woven-fabric composites. The effects of the fiber undulation zone and the fiber braid angle on the elastic modulus of the composites are taken into account in the unit cell. Based on isostrain and isostress assumptions, a standard homogenization procedure is used to calculate the effective elastic properties of woven-fabric composites, and all the final stiffness components are expressed in an explicit form. The results obtained by the model considered agree with published experimental results very well. The relationship between the geometric parameters, such as fiber width, thickness, volume fraction, etc., and the macromechanical behavior of the composites can be obtained by this model. [ABSTRACT FROM AUTHOR]