• MeSH
• geneticky modifikované potraviny MeSH
• kukuřice setá MeSH
• zemědělské plodiny MeSH
• Geografické názvy
• Česká republika MeSH

Transgenic Bt maize is a potentially important tool against insect pest in the EU and other countries. Bt maize (e.g. MON 810, Bt 11) which carries the Bt gene is highly resistant to larval feeding of European corn borer, stalk borer, and Southwestern corn borer, depending on Bt toxin (δ toxin) production. Effective measures used to fight pests may often have positive side-effects in that they may also contribute to reducing mycotoxin concentrations. A systematic review has been used for the purposes of evaluating the studies on the reduction of aflatoxins in Bt maize. According to five studies, Bt maize has significantly lower concentrations of aflatoxins than non-Bt maize hybrids, only one study has shown no significant effect of Bt maize. Other studies have shown mixed results (four studies). The results of these studies were influenced by the year of sampling or by using maize breeding lines selected for resistance to aflatoxin accumulation.

• Klíčová slova
• Bt kukuřice,
• MeSH
• aflatoxiny * škodlivé účinky   MeSH
• bezpečnost potravin MeSH
• geneticky modifikované rostliny * MeSH
• kukuřice setá * genetika   MeSH
• mykotoxiny MeSH
• odolnost vůči nemocem genetika   MeSH
• Publikační typ
• práce podpořená grantem MeSH
• přehledy MeSH

Understanding indirect, trophic-level effects of genetically engineered plants, expressing insecticidal proteins derived from the bacterium, Bacillus thuringiensis (Bt), is essential to the ecological risk assessment process. In this study, we examine potential indirect, trophic-level effects of Bt-sensitive prey using the predator, Harmonia axyridis (Pallas), feeding upon Spodoptera frugiperda (J.E. Smith) larvae, which had delayed development (lower body mass) following ingestion of Cry1Ab maize leaves. We found no adverse effects on development and survival when H. axyridis larvae were fed S. frugiperda larvae that had fed on Cry1Ab maize tissue. Presence of Cry1Ab in H. axyridis decreased considerably after switching to another diet within 48 h. In a no-choice assay, H. axyridis larvae consumed more Bt-fed S. frugiperda than non-Bt-fed larvae. Preference for S. frugiperda feeding on Bt maize was confirmed in subsequent choice assays with H. axyridis predation on Bt-fed, 1-5-d-old S. frugiperda larvae. We suggest that H. axyridis preferred prey, not based on whether it had fed on Bt or non-Bt maize, but rather on larval mass, and they compensated for the nutritional deficiency of lighter larvae through increased consumption. Pest larvae with variable levels of resistance developing on Bt diet are often stunted versus sensitive larvae developing on non-Bt diet. It is possible that such larvae may be preferentially removed from local field populations. These results may have implications for insect resistance management and may be played out under field conditions where seed blends of Bt and non-Bt hybrids are planted.

• MeSH
• Bacillus thuringiensis klasifikace   MeSH
• bakteriální proteiny metabolismus   MeSH
• biologická kontrola škůdců * MeSH
• brouci růst a vývoj   fyziologie   MeSH
• endotoxiny metabolismus   MeSH
• geneticky modifikované rostliny genetika   růst a vývoj   fyziologie   MeSH
• hemolyziny metabolismus   MeSH
• kukuřice setá genetika   růst a vývoj   fyziologie   MeSH
• larva růst a vývoj   mikrobiologie   fyziologie   MeSH
• potravní řetězec * MeSH
• predátorské chování * MeSH
• Spodoptera růst a vývoj   mikrobiologie   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Genetically engineered (GE) crops with stacked insecticidal traits expose arthropods to multiple Cry proteins fromBacillus thuringiensis(Bt). One concern is that the different Cry proteins may interact and lead to unexpected adverse effects on non-target species. Bi- and tri-trophic experiments with SmartStax maize, herbivorous spider mites (Tetranychus urticae), aphids (Rhopalosiphum padi), predatory spiders (Phylloneta impressa), ladybeetles (Harmonia axyridis) and lacewings (Chrysoperla carnea) were conducted. Cry1A.105, Cry1F, Cry3Bb1 and Cry34Ab1 moved in a similar pattern through the arthropod food chain. By contrast, Cry2Ab2 had highest concentrations in maize leaves, but lowest in pollen, and lowest acquisition rates by herbivores and predators. While spider mites contained Cry protein concentrations exceeding the values in leaves (except Cry2Ab2), aphids contained only traces of some Cry protein. Predators contained lower concentrations than their food. Among the different predators, ladybeetle larvae showed higher concentrations than lacewing larvae and juvenile spiders. Acute effects of SmartStax maize on predator survival, development and weight were not observed. The study thus provides evidence that the different Cry proteins do not interact in a way that poses a risk to the investigated non-target species under controlled laboratory conditions.

• MeSH
• Bacillus thuringiensis MeSH
• bakteriální proteiny genetika   MeSH
• členovci * MeSH
• endotoxiny genetika   MeSH
• geneticky modifikované rostliny genetika   MeSH
• hemolyziny genetika   MeSH
• kukuřice setá genetika   MeSH
• larva MeSH
• potravní řetězec * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Transgenic maize MON88017, expressing the Cry3Bb1 toxin from Bacillus thuringiensis (Bt maize), confers resistance to corn rootworms (Diabrotica spp.) and provides tolerance to the herbicide glyphosate. However, prior to commercialization, substantial assessment of potential effects on non-target organisms within agroecosystems is required. The MON88017 event was therefore evaluated under field conditions in Southern Bohemia in 2009-2011, to detect possible impacts on the above-ground arthropod species. The study compared MON88017, its near-isogenic non-Bt hybrid DK315 (treated or not treated with the soil insecticide Dursban 10G) and two non-Bt reference hybrids (KIPOUS and PR38N86). Each hybrid was grown on five 0.5 ha plots distributed in a 14-ha field with a Latin square design. Semiquantitative ELISA was used to verify Cry3Bb1 toxin levels in the Bt maize. The species spectrum of non-target invertebrates changed during seasons and was affected by weather conditions. The thrips Frankliniella occidentalis was the most abundant species in all three successive years. The next most common species were aphids Rhopalosiphum padi and Metopolophium dirhodum. Frequently observed predators included Orius spp. and several species within the Coccinellidae. Throughout the three-year study, analysis of variance indicated some significant differences (P<0.05). Multivariate analysis showed that the abundance and diversity of plant dwelling insects was similar in maize with the same genetic background, for both Bt (MON88017) and non-Bt (DK315) untreated or insecticide treated. KIPOUS and PR38N86 showed some differences in species abundance relative to the Bt maize and its near-isogenic hybrid. However, the effect of management regime on arthropod community was insignificant and accounted only for a negligible portion of the variability.

• MeSH
• biologická kontrola škůdců * MeSH
• brouci fyziologie   MeSH
• endotoxiny metabolismus   MeSH
• genetické inženýrství * MeSH
• geneticky modifikované rostliny genetika   metabolismus   mikrobiologie   MeSH
• hodnocení rizik MeSH
• insekticidy farmakologie   MeSH
• kukuřice setá genetika   metabolismus   mikrobiologie   MeSH
• rezistence k insekticidům * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Thermogenic uncoupling has been proven only for UCP1 in brown adipose tissue. All other isoforms of UCPs are potentially acting in suppression of mitochondrial reactive oxygen species (ROS) production. In this contribution we show that BAT mitochondria can be uncoupled by lauric acid in the range of approximately 100 nM when endogenous fatty acids are combusted by carnitine cycle and beta-oxidation is properly separated from the uncoupling effect. Respiration increased up to 3 times when related to the lowest fatty acid content (BSA present plus carnitine cycle). We also illustrated that any effect leading to more coupled states leads to enhanced H2O2 generation and any effect resulting in uncoupling gives reduced H2O2 generation in BAT mitochondria. Finally, we report doubling of plant UCP transcript in cells as well as amount of protein detected by 3H-GTP-binding sites in mitochondria of shoots and roots of maize seedlings subjected to the salt stress.

• MeSH
• buněčné dýchání MeSH
• financování organizované MeSH
• guanosintrifosfát metabolismus   MeSH
• hnědá tuková tkáň metabolismus   MeSH
• iontové kanály MeSH
• karnitin metabolismus   MeSH
• kořeny rostlin metabolismus   MeSH
• kukuřice setá metabolismus   MeSH
• kyseliny laurové farmakologie   metabolismus   MeSH
• mastné kyseliny metabolismus   MeSH
• membránové proteiny fyziologie   MeSH
• mitochondriální proteiny MeSH
• mitochondrie metabolismus   MeSH
• oxidační stres MeSH
• peroxid vodíku metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rostlinné proteiny fyziologie   MeSH
• rozpřahující látky farmakologie   metabolismus   MeSH
• savci MeSH
• techniky in vitro MeSH
• transportní proteiny fyziologie   MeSH
• vazebná místa MeSH
• výhonky rostlin metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• přehledy MeSH