Effects of temperature on a Chinese population of Amblyseius andersoni (Acari: Phytoseiidae) fed with Tetranychus urticae

International audienceThe development and fecundity of Amblyseius andersoni (Chant) fed with Tetranychus urticae Koch was studied at five different temperatures (17, 20, 25, 30 and 35 °C) and life parameters of the population were calculated. The development, reproduction, longevity, and life table parameters of A. andersoni were significantly affected by the different temperatures. The duration of the egg, larval, protonymph, deutonymph and total immature stages were reduced when the temperature increased. The total oviposition of A. andersoni was highest at 25 °C and lowest at 35 °C, and the daily average oviposition increased as the temperature increased, but few eggs were laid at 17 °C. The values of the intrinsic rate of increase (rm, 0.108--0.200), net reproduction rate (R0, 18.71--36.47) and the mean generation time (T, 14.68--29.73) significantly differed among the five temperatures. The highest net reproduction rate (R0 = 36.47) was obtained at 25 °C. The results of this study indicated that A. andersoni has a high inherent potential for the control of the T. urticae at certain temperatures

Comparison of gene expression profiles in Bacillus megaterium treated tobacco leaves using microarray

The MP agent, prepared from Bacillus megaterium isolated from the soil near tobacco fields, can improve metabolic products, and hence the aroma, of tobacco (Nicotiana tabacum) leaf. To explore genes regulating metabolic responses in tobacco leaf, we used microarrays to analyze differentially expressed genes in tobacco leaves subjected to various treatments. The expressed genes were classified into six groups based on their expression profile. In total, 753 genes were significantly differentially expressed between microorganism-treated and water-treated samples. Gene ontology (GO) analyses showed that most of these genes were involved in metabolic and cellular processes. Some upregulated genes were related to the plant defense response, such as NtMMP1 and NtACRE231. Some genes were involved in metabolism responses, such as NtDXS. Semi-quantitative reverse transcriptase (RT)-PCR analysis of NtMMP1 and quantitative RT-PCR analysis of NtDXS showed that their expression levels increased after MP agent treatment, confirming the microarray results. We evaluated NtMMP1 and NtDXS in terms of their associations with Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Phylogenetic analyses of NtMMP1, NtACRE231, and NtDXS revealed their relationships with homologs in other species. These microarray data increase our understanding of the mechanisms by which MP agent induces a metabolic response in tobacco leavesKey words: Nicotiana tabacum, Microarray, MP agent, plant defense response, aroma

Genetic variation analysis of reemerging porcine epidemic diarrhea virus prevailing in central China from 2010 to 2011

Porcine epidemic diarrhea has re-emerged with devastating impact in central China since October 2010. To investigate and analyze the reason of this outbreak, the M and ORF3 genes of 15 porcine epidemic diarrhea viruses (PEDV), which were collected from different areas of central China during October 2010 and December 2011, were amplified by reverse transcriptase polymerase chain reaction, cloned, sequenced, and analyzed. Sequence analyses showed that the nucleotides and amino acids were changed at some sites in the M and ORF3 genes of the 15 PEDV strains compared with those genes of CV777 reference strain. Based on the phylogenetic analyses, PEDVs in central China and reference strains could be separated into three groups: G1, G2, and G3. The 15 PEDV strains belonged to G3 group and showed a close relationship with Korean strains (2007), Thai strains (2007–2008), and partial other Chinese strains (2010–2011), but differed genetically from European strains (Br1/87) and the vaccine strain (CV777 vs) being used in China. Furthermore, all 15 PEDV strains from central China and some other isolates in China from 2003 to 2007 (LJB-03, QH, and LZC) belonged to different group. Therefore, PEDV exhibits rapid variation and genetic evolution, and the currently prevailing PEDV strains in central China are a new genotype

Carbohydrate intake quality and gestational diabetes mellitus, and the modifying effect of air pollution

BackgroundNutritional management is the cornerstone of gestational diabetes mellitus (GDM) prevention. High quality instead of low quantity of carbohydrate intake has been paying attention in controlling glycemia. Air pollution exposure can be interacted with dietary sourced nutrients, which may modify the associations with GDM. This study aims to explore the associations between overall quality of carbohydrate intake and GDM as well as the modifying effect of prenatal air pollution exposure.MethodsCarbohydrate quality index (CQI) was calculated was calculated by summing scores of the four components; Land use regression prediction models were used to assess the air pollution exposure levels. GDM definition was based on 75 g glucose tolerance test results. Associations between pre-pregnancy CQI, pre-natal air pollution as well as the modifying effect on GDM were explored based on a birth cohort in China.ResultsA total of 3,183 participants were included, of which 784 (24.63%) were diagnosed with GDM. Higher pre-pregnancy CQI was associated with a lower incidence of GDM [odds ratio (OR) = 0.75, 95% confidence interval (CI): 0.56–0.99, Pfor trend = 0.04], especially for higher fasting blood glucose related GDM (OR = 0.66, 95% CI: 0.47, 0.91). Higher air pollution exposure before and during pregnancy was associated with a greater risk of GDM. Higher exposure to particulate matter with an aerodynamic diameter of < 2.5 μm (Pfor interaction < 0.01), particulate matter with an aerodynamic diameter of < 10 μm (Pfor interaction < 0.01), and sulfur dioxide (Pfor interaction = 0.02) during pregnancy decreased the beneficial effect of high pre-pregnancy CQI on GDM.ConclusionCQI related dietary interventions pre-pregnancy to prevent GDM incidence should be considered. Women who are planning to be pregnant should avoid high exposure to air pollution during pregnancy