Inhibition of dipeptidyl peptidase-IV (DPP-IV) activity is a promising strategy for treatment of type 2 diabetes. In the current study, DPP-IV inhibitory peptides were identified from mare whey protein hydrolysates obtained by papain. The results showed that all the mare whey protein hydrolysates obtained at various hydrolysis durations possessed more potent DPP-IV inhibitory activity compared with intact whey protein. The 4-h hydrolysates showed the greatest DPP-IV inhibitory activity with half-maximal inhibitory concentration of 0.18 mg/mL. The 2 novel peptides from 4-h hydrolysate fractions separated by successive chromatographic steps were characterized by liquid chromatography-electrospray ionization tandem mass spectrometry. The novel peptides Asn-Leu-Glu-Ile-Ile-Leu-Arg and Thr-Gln-Met-Val-Asp-Glu-Glu-Ile-Met-Glu-Lys-Phe-Arg, which corresponded to β-lactoglobulin 1 f(71-77) and β-lactoglobulin 1 f(143-155), demonstrated DPP-IV inhibitory activity with half-maximal inhibitory concentrations of 86.34 and 69.84 μM, respectively. The DPP-IV inhibitory activity of the 2 peptides was retained or even improved after simulated gastrointestinal digestion in vitro. Our findings indicate that mare whey protein-derived peptides may possess potential as functional food ingredients in the management of type 2 diabetes.

Baseline sensitivity to flumorph, a carboxylic acid amide (CAA) fungicide used to control some oomycetes, was examined using 83 Phytophthora capsici isolates, resulting in a unimodal distribution of effective concentration for 50% inhibition of mycelial growth ranging from 0AE716 to 1AE363, with a mean of 1AE033 ± 0AE129 lg mL )1 . To assess the potential risk of developing flumorph resistance, 13 flumorph-resistant mutants of P. capsici were obtained using ultraviolet irradiation. Most of these mutants and their progeny had high levels of fitness, including mycelial growth, sporulation and virulence. The resistance to flumorph changed slightly, either increasing or decreasing, after 10 transfers on agar media. Cross-resistance was found between flumorph and other CAA fungicides (dimethomorph and iprovalicarb), but not between flumorph and non-CAA fungicides (cymoxanil, metalaxyl, azoxystrobin and cyazofamid). To investigate the genetics of the flumorph resistance, 619 progeny were obtained by self-crossing and sexual hybridization. Segregation of sensitivity to fungicide was measured as a ratio of sensitive (S) to resistant (R) isolates. Segregation of the progeny, from self-crossed isolate PCAS1 (flumorph resistant), was 1:15 in the first generation; and 0:1 or 1:15 in the second generation. In sexual hybridization, segregation of progeny was 0:1 and 1:7 for R · R hybridization; and 1:3 for R · S hybridization. Therefore, the resistance of P. capsici against flumorph was controlled by two dominant genes.

To characterize the prevalence of viruses associated with grapevine leafroll disease in China, 249 grapevine (Vitis spp.) samples (86 popular cultivars and a rootstock) from 19 provinces and regions were collected and tested for Grapevine leafroll-associated virus 1 (GLRaV-1), GLRaV-2, GLRaV-3, GLRaV-4, and GLRaV-4 strain 5 by SYBR Green real-time reverse-transcription polymerase chain reaction (RT-PCR), and RT-PCR and sequencing. GLRaV-3 was found in 100% of the samples while GLRaV-1, GLRaV-2, and GLRaV-4 were detected in 24.9% (62/249), 15.3% (38/249), and 0.80% (2/249) of the samples, respectively. Single infections with GLRaV-3 were found in 66.3% (165/249) of the samples, and the remaining samples were mixed infections of GLRaV-3 with one or two other GLRaVs, those with GLRaV-1 being the most common (18.5%, 46/249). The genetic variability of Chinese GLRaV-3 isolates was characterized based on the coat protein (CP) gene. In total, 153 full-length CP gene sequences (94 sequences newly generated) of Chinese GLRaV-3 isolates from different grapevine-growing regions showed 89.3 to 100.0% and 92.7 to 100.0% identity at the nucleotide and amino acid levels, respectively. The average nucleotide diversity for the population of Chinese GLRaV-3 isolates was estimated at 0.037 (standard error = 0.0032). GLRaV-3 isolates from China segregated into five distinct phylogenetic groups and two novel recombination events were found in the viral population. This is the first and most extensive report of the prevalent species of GLRaV in China, which also provides an assessment of genetic variability of GLRaV-3 Chinese isolates.

Selenium (Se) is an essential trace element for humans and animals. A hydroponic experiment was performed to study the effects of sulphur (S) on Se uptake, translocation, and assimilation in wheat (Triticum aestivum L.) seedlings. Sulphur starvation had a positive effect on selenate uptake and the form of Se supplied greatly influenced Se speciation in plants. Compared with the control plants, Se uptake by the S-starved plants was enhanced by 4.81-fold in the selenate treatment, and selenate was readily transported from roots to shoots. By contrast, S starvation had no significant effect on selenite uptake, and selenite taken up by roots was rapidly converted to organic forms and tended to accumulate in roots. X-ray absorption near edge spectroscopy (XANES) analysis showed that organic forms of selenium, including selenocystine, Se-methyl-selenocysteine (MeSeCys), and selenomethionine-Se-oxide, were dominant in the plants exposed to selenite and accounted for approximately 90 % of the total Se. Whereas selenate remained as the dominant species in the roots and shoots exposed to selenate, with little selenate converted to selenite and MeSeCys. Besides, sulphur starvation increased the proportion of inorganic Se species in the selenate-supplied plants, but had no significant effects on Se speciation in plants exposed to selenite. The present study provides important knowledge to understand the associated mechanism of Se uptake and metabolism in plants.

Rumplessness in Hongshan chickens has been reported as a novel sex-linked characteristic. Re-sequencing data suggest that a pseudogene on the Z chromosome, LOC431648, is affiliated with this phenotype. In this study, we chose 23 rumpless and 25 normal Hongshan chickens to localize the potential variation by means of a genome-wide association study using a high density microarray. A region on the Z chromosome was found to be closely associated with rumplessness in Hongshan chickens. The region, located in gene LINGO2, was approximately 3 Mb away from pseudogene LOC431648. The function of this gene has not yet been studied in birds. Differential expression of the candidate genes in the tail feather follicles was not detected by q-PCR, which suggests that the rumplessness trait could be attributed to other genetic mechanisms.

Efforts to control viral diseases of grapevine include the production of certified material and development of virus‐resistant transgenic grapevines. However, effective antiviral agents, once the viruses have infected the plants, are still lacking. This study shows that a crude garlic extract has significant antiviral activity against grapevine viruses. Replication of grapevine leafroll‐associated virus 2 (GLRaV‐2) was obviously inhibited in grapevine cv. Cabernet Sauvignon calli treated with diluted (1:100) garlic extract. The relative RNA levels of GLRaV‐2 and grapevine fleck virus (GFkV) in cv. Summer Black grapevine in in vitro‐grown plantlets 10 days after treatment with diluted (1:100) garlic extract were about 22% and 20%, respectively, of that in controls. The viral RNA accumulation of GLRaV‐2, GFkV, grapevine virus A (GVA), grapevine fanleaf virus (GFLV) and grapevine rupestris stem pitting‐associated virus (GRSPaV) in field‐grown grapevine cv. Centennial Seedless plants sprayed with diluted (1:100) garlic extract were about 31–40%, 26–38%, 18–31%, 17–42% and 15–18%, respectively, of that in controls. Moreover, the garlic extract treatment led to a significant decrease in viral RNA accumulation of GLRaV‐3, GLRaV‐2, GVA, GFkV, GFLV, GRSPaV and grapevine Pinot Gris virus in pot‐grown grapevine cv. Shine Muscat plants, and viral disease symptoms in these plants were obviously attenuated. In addition, this extract significantly induced expression of pathogenesis‐related protein genes and stimulated activity of antioxidant enzymes in grapevines. Taken together, these results indicate that the crude garlic extract acts as a significant inhibitor against a broad range of grapevine viruses.

To determine prevalence and distribution of Grapevine leafroll-associated virus 7 (GLRaV-7) in China, a total of 213 grapevine (Vitis spp.) samples (92 popular cultivars) from 13 Chinese provinces and regions were tested for the presence of GLRaV-7 by reverse transcription polymerase chain reaction (RT-PCR) assays and sequencing. GLRaV-7 was found in 40Á4% of the samples, and shown to be widely distributed in major grapevine growing areas in China. GLRaV-7 was found in more than 50 grapevine cultivars. Some popular grape cultivars showed a high incidence of GLRaV-7 infection, such as Manicure Finger (100%), Cabernet Sauvignon (83Á3%), Merlot (60%), Fujimineri (60%) and Red Globe (50%). The genetic variability of GLRaV-7 isolates was characterized based on partial nucleotide sequences (nucleotides 945-1329 and 97-598 of the ORF) of heat shock protein 70 homologue (HSP70h) and 61-kDa protein (p61) (nucleotides 1073-1572 of the ORF) genes. The overall mean values of nucleotide diversity were low (ranging from 0Á009 to 0Á066), and phylogenetic analysis based on p61 showed that the GLRaV-7 isolates segregated into three phylogenetic clusters. The results also showed that two previously described primer pairs failed to amplify a wide range of GLRaV-7 isolates present in China. However, a new primer pair reported here, based on the p61 gene and its associated downstream intergenic region, detected more GLRaV-7 Chinese isolates. This is the first report on the prevalence and distribution of GLRaV-7 in China, and also provides an improved RT-PCR assay for detecting the virus.

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