Knockdown of Polyphenol Oxidase Gene Expression in Potato (Solanum tuberosum L.) with Artificial MicroRNAs.

It is of great importance and interest to develop crop varieties with low polyphenol oxidase (PPO) activity for the food industry because PPO-mediated oxidative browning is a main cause of post-harvest deterioration and quality loss of fresh produce and processed foods. We recently demonstrated that potato tubers with reduced browning phenotypes can be produced by inhibition of the expression of several PPO gene isoforms using artificial microRNA (amiRNA) technology. The approach introduces a single type of 21-nucleotide RNA population to guide silencing of the PPO gene transcripts in potato tissues.

Design, Construction, and Validation of Artificial MicroRNA Vectors Using Agrobacterium-Mediated Transient Expression System.

Artificial microRNA (amiRNA) technology utilizes microRNA (miRNA) biogenesis pathway to produce artificially selected small RNAs using miRNA gene backbone. It provides a feasible strategy for inducing loss of gene function, and has been applied in functional genomics study, improvement of crop quality and plant virus disease resistance. A big challenge in amiRNA applications is the unpredictability of silencing efficacy of the designed amiRNAs and not all constructed amiRNA candidates would be expressed effectively in plant cells.

Genomic Comparison of Non-Typhoidal Salmonella enterica Serovars Typhimurium, Enteritidis, Heidelberg, Hadar and Kentucky Isolates from Broiler Chickens.

Background: Non-typhoidal Salmonella enterica serovars, associated with different foods including poultry products, are important causes of bacterial gastroenteritis worldwide. The colonization of the chicken gut by S. enterica could result in the contamination of the environment and food chain.

Identification and characterization of rye genes not expressed in allohexaploid triticale.

Background: One of the most important evolutionary processes in plants is polyploidization. The combination of two or more genomes in one organism often initially leads to changes in gene expression and extensive genomic reorganization, compared to the parental species. Hexaploid triticale (x Triticosecale) is a synthetic hybrid crop species generated by crosses between T.

Antibiotics in Canadian poultry productions and anticipated alternatives.

The use of antibiotics in food-producing animals has significantly increased animal health by lowering mortality and the incidence of diseases. Antibiotics also have largely contributed to increase productivity of farms. However, antibiotic usage in general and relevance of non-therapeutic antibiotics (growth promoters) in feed need to be reevaluated especially because bacterial pathogens of humans and animals have developed and shared a variety of antibiotic resistance mechanisms that can easily be spread within microbial communities.

An in vivo transient expression system can be applied for rapid and effective selection of artificial microRNA constructs for plant stable genetic transformation.

The utility of artificial microRNAs (amiRNAs) to induce loss of gene function has been reported for many plant species, but expression efficiency of the different amiRNA constructs in different transgenic plants was less predictable. In this study, expressions of amiRNAs through the gene backbone of Arabidopsis miR168a were examined by both Agrobacterium-mediated transient expression and stable plant genetic transformation. A corresponding trend in expression of amiRNAs by the same amiRNA constructs between the transient and the stable expression systems was observed in the experiments.

In vitro and in vivo antibacterial activities of cranberry press cake extracts alone or in combination with β-lactams against Staphylococcus aureus.

Background: Cranberry fruits possess many biological activities partly due to their various phenolic compounds; however the underlying modes of action are poorly understood. We studied the effect of cranberry fruit extracts on the gene expression of Staphylococcus aureus to identify specific cellular processes involved in the antibacterial action.

Methods: Transcriptional profiles of four S.

Host-induced gene silencing of wheat leaf rust fungus Puccinia triticina pathogenicity genes mediated by the Barley stripe mosaic virus.

Rust fungi are devastating plant pathogens and several Puccinia species have a large economic impact on wheat production worldwide. Disease protection, mostly offered by introgressed host-resistance genes, is often race-specific and rapidly overcome by newly-emerging virulent strains. Extensive new genomic resources have identified vital pathogenicity genes but their study is hampered because of the biotrophic life styles of rust fungi.

Optimization of furfural and 5-hydroxymethylfurfural production from wheat straw by a microwave-assisted process.

Optimization of acid-catalyzed conversion conditions of wheat straw into furfural, 5-hydroxymethylfurfural (HMF), glucose, and xylose was studied by response surface methodology (RSM). A central composite design (CCD) was used to determine the effects of independent variables, including reaction temperature (140-200 °C), residence time (1-41 min), pH (0.1-2.

Acid-catalyzed conversion of xylose, xylan and straw into furfural by microwave-assisted reaction.

Furfural is a biomass derived-chemical that can be used to replace petrochemicals. In this study, the acid-catalyzed conversion of xylose and xylan to furfural by microwave-assisted reaction was investigated at selected ranges of temperature (140-190°C), time (1-30 min), substrate concentration (1:5-1:200 solid:liquid ratio), and pH (2-0.13).

Characteristics of lignin from flax shives as affected by extraction conditions.

Lignin, a polyphenolic molecule, is a major constituent of flax shives. This polyphenolic molecular structure renders lignin a potential source of a variety of commercially viable products such as fine chemicals. This work compares the performance of different lignin isolation methods.

Identification of the Phytoplasma Associated with Wheat Blue Dwarf Disease in China.

Wheat blue dwarf disease (WBD) was first reported in China in the 1960s. It has caused severe losses on several occasions in winter wheat (Triticum aestivum) in northwestern China, and the nature of the pathogenic agent has been unknown. Here we have shown that WBD was caused by a 16SrI-C phytoplasma transmitted by Psammotettix striatus.

Isolation and characterization of lignins extracted from flax shives using pressurized aqueous ethanol.

High-molecular weight lignins (HML) and low-molecular weight lignins (LML) were extracted from flax shives using pressurized 30% aqueous ethanol, and isolated by precipitation and ultrafiltration. The isolated lignin samples and two commercial lignins were assayed for monolignol content and functional groups, solubility assays, thermal analysis using differential scanning calorimetry (DSC), size exclusion chromatography (SEC), and Fourier transform infrared spectroscopy (FT-IR). The highest yield of HML was 13.

In vitro bioavailability of phenolic compounds from five cultivars of frozen sweet cherries (Prunus avium L.).

The bioavailability of phenolic compounds from five cultivars of frozen sweet cherries was assessed by a digestion process involving pepsin-HCl digestion (to simulate gastric digestion) and pancreatin digestion with bile salts (to simulate small intestine conditions) and dialyzed to assess serum- and colon-available fractions. After pepsin digestion, the % recovery of total phenolics, relative to the original starting material, increased, whereas the % anthocyanins did not change. Following pancreatic digestion and dialysis, the total phenolics in the IN (serum-available) fraction was about 26-30% and the OUT (colon-available) fraction was about 77-101%.

Repellency of a wireworm, Agriotes obscurus (Coleoptera: Elateridae), on exposure to synthetic insecticides in a soil-less bioassay.

A soil-less bioassay arena to test repellency of wireworms (A. obscurus) to insecticides and carrier solvents is described. The bioassay and variables measured distinguish between shorter-range (contact and/or volatile) and longer-range (volatile) repellency.

Soil bioassay for studying behavioral responses of wireworms (Coleoptera: Elateridae) to insecticide-treated wheat seed.

A bioassay for observing wireworm behavior in soil is described. The bioassay permits analysis of orientation, feeding, repellency, and postcontact toxicity behaviors of wireworms in response to insecticide-treated wheat seeds. Wireworm positions were recorded every 5 min for 3 h, and the time required to orient to and contact seeds, and the duration of individual feeding events, was calculated.

Influence of mixtures of kaolin particle film and synthetic insecticides on mortality of larval obliquebanded leafrollers (Lepidoptera: Tortricidae) from resistant and susceptible populations.

Experiments were conducted to determine potential interactions between kaolin particle film and three insecticides on neonate larvae of the obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae). Kaolin did not significantly affect the toxicity of azinphosmethyl or indoxacarb to an insecticide-susceptible population when applied simultaneously with either insecticide in a 7-d leaf disk bioassay. Methoxyfenozide was slightly more toxic to the same leafroller population when coapplied with kaolin.

Fractionation of flax shives by water and aqueous ammonia treatment in a pressurized low-polarity water extractor.

Fractionation of flax shives into cellulose, hemicellulose, and lignin with a two-stage extraction process using water and aqueous ammonia was carried out in a pressurized low-polarity water extractor operated at different temperatures, flow rates, and ammonia concentrations. During the first stage with water, 84% of hemicellulose and 32% of lignin were removed at 190 degrees C at a flow rate of 1.5 mL/min for 30 min.

Yield and composition of grape seed oils extracted by supercritical carbon dioxide and petroleum ether: varietal effects.

Grape seed has a well-known potential for production of oil as a byproduct of winemaking and is currently produced as a specialty oil byproduct of wine manufacture. Seed oils from eight varieties of grapes crushed for wine production in British Columbia were extracted by supercritical carbon dioxide (SCE) and petroleum ether (PE). Oil yields by SCE ranged from 5.

Nicotiana occidentalis: A New Herbaceous Host for Blueberry scorch virus.

Blueberry scorch virus(BlScV) is a carlavirus that causes a serious disease of blueberries (Vaccinium corymbosum L.) in North America (2). In aphid-transmission studies of BlScV using blueberry as host and test species, we found the rate of transmission to be low, and a lengthy incubation period was required before BlScV could be detected.

Molecular aspects of plant virus transmission by olpidium and plasmodiophorid vectors.

The genome structures of a large number of viruses transmitted by olpidium and plasmodiophorid vectors have been determined. The viruses are highly diverse, belonging to 12 genera in at least 4 families. Plasmodiophorids are now classified as protists rather than true fungi.

Anthocyanin metabolites in human urine and serum.

In the present study we investigated the metabolic conversion of cyanidin glycosides in human subjects using solid-phase extraction,HPLC-diode array detector, MS, GC, and enzymic techniques. Volunteers consumed approximately 20 g chokeberry extract containing 1.3 g cyanidin 3-glycosides (899 mg cyanidin 3-galactoside, 321 mg cyanidin 3-arabinoside, 51 mg cyanidin 3-xyloside and 50 mg cyanidin 3-glucoside).

Nitrogen mobilization, nitrogen uptake and growth of cuttings obtained from poplar stock plants grown in different N regimes and sprayed with urea in autumn.

Nitrogen mobilization, nitrogen uptake and growth of cuttings obtained from poplar stock plants fertigated with different nitrogen (N) treatments and sprayed with urea in autumn were studied. Stock plants propagated from poplar cuttings were trained to a single shoot and fertigated with 0, 5, 10, 15 or 20 mmol l(-1) N during the first growing season. In October, a subset of stock plants from each N fertigation treatment was sprayed twice with either 3% urea or water, and overwintered outside.