Transportability of non-target arthropod field data for the use in environmental risk assessment of genetically modified maize in Northern Mexico

In country, non-target arthropod (NTA) field evaluations are required to comply with the regulatory process for cultivation of genetically modified (GM) maize in Mexico. Two sets of field trials, Experimental Phase and Pilot Phase, were conducted to identify any potential harm of insect-protected and glyphosate-tolerant maize (MON89Ø34-3 × MON-88Ø17-3 and MON-89Ø34-3 × MON-ØØ6Ø3-6) and glyphosatetolerant maize (MON-ØØ6Ø3-6) to local NTAs compared to conventional maize. NTA abundance data were collected at 32 sites, providing high geographic and environmental diversity within maize production areas from four ecological regions (ecoregions) in northern Mexico. The most abundant herbivorous taxa collected included field crickets, corn flea beetles, rootworm beetles, cornsilk flies, aphids, leafhoppers, plant bugs and thrips while the most abundant beneficial taxa captured were soil mites, spiders, predatory ground beetles, rove beetles, springtails (Collembola), predatory earwigs, ladybird beetles, syrphid flies, tachinid flies, minute pirate bugs, parasitic wasps and lacewings. Across the taxa analysed, no statistically significant differences in abundance were detected between GM maize and the conventional maize control for 69 of the 74 comparisons (93.2%) indicating thatthe single or stacked insect-protected and herbicide-tolerant GM traits generally exert no marked adverse effects on the arthropod populations compared with conventional maize. The distribution of taxa observed in this study provides evidence that irrespective of variations in overall biodiversity of a given ecoregion, important herbivore, predatory and parasitic arthropod taxa within the commercial maize agroecosystem are highly similar indicating that relevant data generated in one ecoregion can be transportable for the risk assessment of the same or similar GM crop in another ecoregion

Isolation and study of a ubiquitously expressed tomato pectin methylesterase regulatory region

Pectin methylesterase (PME) is an enzyme located in the plant cell wall of higher plants whose physiological role is largely unknown. We had isolated a PME gene from a tomato genomic library, including 2.59 kb of 5′ flanking region and the coding region. Both coding and promoter region were sequenced and computer analyzed. Tobacco transgenic plants were created harboring constructs in which 2.596 Kb, 1.306 Kb and 0.267 Kb sizes of the promoter were driving the expression of β-Glucuronidase gene (GUS). GUS activity was studied by histochemical and fluorometric assays. Two introns of 106 and 1039 bp were found in the coding region and phylogenetic analysis placed this PME gene closer to genes from Citrus sinensis and Arabidopsis thaliana than tomato fruit-specific PME genes. In the promoter, it was found direct repeats, perfect inverted repeats and light responsive elements. GUS histochemical analysis showed activity in all plant tissues with the exception of pollen. The reduction in the promoter size induced a reduction in GUS activity in root, stem and leaf. Furthermore, root and leaf showed the highest and lowest activity, respectively. We had isolated a tomato PME gene with novel characteristics as compared with other known PME genes from tomato

Photocatalytic hydrogen production over titania modified by gold – Metal (palladium, nickel and cobalt) catalysts

The photocatalytic production of hydrogen on modified Au/TiO2-based photocatalysts by using water/methanol mixtures was studied. The main goal was to study the effect of surface modification of Au/TiO2 with Pd, Ni and Co on H2 production under UV light irradiation (λ ca. 254 nm). Catalysts were produced by depositing Pd, Ni or Co precursors (nitrates hydrated salts) on TiO2 (Evonik, P25) by incipient wetness impregnation followed by thermal treatment under H2 (Pd and Co) or air (Ni). Thereafter, Au was incorporated by deposition-precipitation with urea (DPU method) and then the catalysts were thermally activated again under air flow. The photocatalysts were characterized by UV?Vis diffuse reflectance, HAADF-TEM, EDXS, FTIR CO adsorption, XPS and photoluminescence. In order to obtain detailed information about the composition of the nanoparticles, high-resolution elemental analyses (EDXS line scans) were performed. The Au-Pd, Au-Ni and Au-Co on TiO2 photocatalysts showed higher performance for H2 production (266, 256 and 171 mmol H2 mmolAu −1 h−1, respectively) compared to the Au/TiO2 material (106 mmol H2 mmolAu −1 h−1). PL results showed that the improved H2 production rate could be explained by an enhanced charge separation. The highest H2 production showed by the Au-Pd/TiO2 sample could be attributed to synergistic effects, derived from the interaction between Au and Pd particles. For the Au-Ni/TiO2 and Au-Co/TiO2 samples it is proposed that nickel or cobalt oxides worked as promoters (with additives effects) because of the formation of a p-n heterojunction.Fil: Barrios, Celina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina. Universidad Nacional Autónoma de México; MéxicoFil: Albiter, E.. Universidad Nacional Autónoma de México; MéxicoFil: Gracia y Jimenez, J. M.. Benemérita Universidad Autónoma de Puebla; MéxicoFil: Tiznado, H.. Universidad Nacional Autónoma de México; MéxicoFil: Romo Herrera, J.. Universidad Nacional Autónoma de México; MéxicoFil: Zanella, R.. Universidad Nacional Autónoma de México; Méxic

Fabrication of macro-mesoporous zirconia-alumina materials with a one-dimensional hierarchical structure

A series of one dimensional (1D) zirconia/alumina nanocomposites were prepared by the deposition of zirconium species onto the 3D framework of boehmite nanofibres formed by dispersing boehmite nanofibres into butanol solution. The materials were calcined at 773K and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), N2 adsorption/desorption, infrared emission spectroscopy (IES). The results demonstrated that when the molar percentage X=100*Zr/(Al+Zr) was > 30 %, extremely long ZrO2/Al2O3 composite nanorods with evenly distributed ZrO2 nanocrystals on the surface were formed. The stacking of such nanorods gave rise to a new kind of macroporous material without the use of any organic space filler\template or other specific technologies. The mechanism for the formation of long ZrO2/Al2O3 composite nanorods was proposed in this work