The Colorado potato beetle (CPB; Leptinotarsa decemlineata) is an important potato pest with known resistance to pyrethroids and organophosphates in Czechia. Decreased efficacy of neonicotinoids has been observed in last decade. After the restriction of using chlorpyrifos, thiacloprid and thiamethoxam by EU regulation, growers seek for information about the resistance of CPB to used insecticides and recommended antiresistant strategies. The development of CPB resistance to selected insecticides was evaluated in bioassays in 69 local populations from Czechia in 2017-2022 and in 2007-2022 in small plot experiments in Zabcice in South Moravia. The mortality in each subpopulation in the bioassays was evaluated at the field-recommended rates of insecticides to estimate the 50% and 90% lethal concentrations (LC50 and LC90, respectively). High levels of CPB resistance to lambda-cyhalothrin and chlorpyrifos were demonstrated throughout Czechia, without significant changes between years and regions. The average mortality after application of the field-recommended rate of lambda-cyhalothrin was influenced by temperature before larvae were sampled for bioassays and decreased with increasing temperature in June. Downwards trends in the LC90 values of chlorpyrifos and the average mortality after application of the field-recommended rate of acetamiprid in the bioassay were recorded over a 6-year period. The baseline LC50 value (with 95% confidence limit) of 0.04 mg/L of chlorantraniliprole was established for Czech populations of CPBs for the purpose of resistance monitoring in the next years. Widespread resistance to pyrethroids, organophosphates and neonicotinoids was demonstrated, and changes in anti-resistant strategies to control CPBs were discussed.

• MeSH
• brouci * účinky léků   MeSH
• dursban * farmakologie   MeSH
• insekticidy * farmakologie   MeSH
• larva účinky léků   MeSH
• neonikotinoidy * farmakologie   MeSH
• nitrily farmakologie   MeSH
• pyrethriny farmakologie   MeSH
• rezistence k insekticidům * MeSH
• Solanum tuberosum parazitologie   MeSH
• thiamethoxam MeSH
• thiaziny * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• cyhalothrin MeSH Prohlížeč
• dursban * MeSH
• insekticidy * MeSH
• neonikotinoidy * MeSH
• nitrily MeSH
• pyrethriny MeSH
• thiacloprid MeSH Prohlížeč
• thiamethoxam MeSH
• thiaziny * MeSH

Phytophthora infestans is the pathogen of potato late blight, which is one of the most serious diseases of the potato. Myxobacteria, especially Myxococcus, become a valuable biological control resource due to their preponderant abilities to produce various secondary metabolites with novel structure and remarkable biological activity. In a previous study, Myxococcus fulvus B25-I-3 with antagonistic activity against P. infestans was isolated from an environmental sample by rabbit fecal induction method. The biocontrol mechanism of M. fulvus B25-I-3 against P. infestans and its control efficiency on potato late blight were studied. The results showed that the active substances produced by strain B25-I-3 had strong inhibitory effect on the asexual reproduction and sexual reproduction of P. infestans. In addition, the active substances could reduce the content of soluble proteins and the activity of the protective enzymes (polyphenol oxidase, peroxidase, phenylalanine ammonia lyase, superoxide dismutase) in P. infestans and increase the oxidative damage and permeability of cell membrane. And the active substances could inhibit the infection of the detached potato leaves by P. infestans significantly. In conclusion, M. fulvus B25-I-3 can produce active substances against P. infestans and has potential value to develop into biological pesticides for the control of potato late blight. The completion of this work may provide basic data for the isolation and identification of active substances and the development of pesticides against potato late blight.

• MeSH
• biologická kontrola škůdců * metody   MeSH
• mikrobiální interakce fyziologie   MeSH
• Myxococcus * fyziologie   MeSH
• nemoci rostlin * parazitologie   prevence a kontrola   MeSH
• Phytophthora infestans * fyziologie   MeSH
• Solanum tuberosum * mikrobiologie   parazitologie   MeSH
• Publikační typ
• časopisecké články MeSH

The potato cyst nematodes Globodera pallida and G. rostochiensis are economically important plant pathogens causing losses to UK potato harvests estimated at £50 m/ year. Implications of climate change on their future pest status have not been fully considered. Here, we report growth of female G. pallida and G. rostochiensis over the range 15 to 25°C. Females per plant and their fecundity declined progressively with temperatures above 17.5°C for G. pallida, whilst females per plant were optimal between 17.5 and 22.5°C for G. rostochiensis. Relative reproductive success with temperature was confirmed on two potato cultivars infected with either species at 15, 22.5 and 25°C. The reduced reproductive success of G. pallida at 22.5°C relative to 15°C was also recorded for a further seven host cultivars studied. The differences in optimal temperatures for reproductive success may relate to known differences in the altitude of their regions of origin in the Andes. Exposure of G. pallida to a diurnal temperature stress for one week during female growth significantly suppressed subsequent growth for one week at 17.5°C but had no effect on G. rostochiensis. However, after two weeks of recovery, female size was not significantly different from that for the control treatment. Future soil temperatures were simulated for medium- and high-emission scenarios and combined with nematode growth data to project future implications of climate change for the two species. Increased soil temperatures associated with climate change may reduce the pest status of G. pallida but benefit G. rostochiensis especially in the southern United Kingdom. We conclude that plant breeders may be able to exploit the thermal limits of G. pallida by developing potato cultivars able to grow under future warm summer conditions. Existing widely deployed resistance to G. rostochiensis is an important characteristic to retain for new potato cultivars.

• Klíčová slova
• Globodera pallida, Globodera rostochiensis, climate change, plant pathogens, potato cyst nematode, soil temperature simulations, soil-borne pests,
• MeSH
• klimatické změny * MeSH
• půda MeSH
• Solanum tuberosum parazitologie   MeSH
• Tylenchoidea fyziologie   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Spojené království MeSH
• Názvy látek
• půda MeSH

Several recombinant derivatives of serine protease inhibitor called silk protease inhibitor 2 (SPI2), which is a silk component in Galleria mellonella (Lepidoptera, Insecta), were prepared in the expression vector Pichia pastoris. Both the native and the recombinant protease inhibitors were highly active against subtilisin and proteinase K. The synthetic SPI2 gene with Ala codon in the P1 position was fused with mGFP-5 to facilitate detection of the transgene and its protein product. A construct of the fusion gene with plant regulatory elements (promoter 35S and terminator OCS) was inserted into the binary vector pRD400. The final construct was introduced into Agrobacterium tumefaciens that was then used for genetic transformation of the potato variety Velox. The transgene expression was monitored with the aid of ELISA employing polyclonal antibody against natural SPI2. In vitro tests showed increased resistance to the late blight Phytophthora infestans in several transformed lines. No effect was seen on the growth, mortality, life span or reproduction of Spodoptera littoralis (Lepidoptera, Insecta) caterpillars, while feeding on transformed potato plants expressing the fusion protein, indicating that the transformed potatoes may be harmless to non-target organisms.

• MeSH
• exprese genu MeSH
• extracelulární prostor enzymologie   MeSH
• genetické inženýrství škodlivé účinky   metody   MeSH
• geneticky modifikované rostliny MeSH
• hmyzí proteiny genetika   MeSH
• Lepidoptera genetika   MeSH
• nemoci rostlin parazitologie   MeSH
• odolnost vůči nemocem genetika   MeSH
• Phytophthora infestans fyziologie   MeSH
• Pichia genetika   MeSH
• Solanum tuberosum cytologie   genetika   imunologie   parazitologie   MeSH
• Spodoptera MeSH
• subtilisin antagonisté a inhibitory   metabolismus   MeSH
• transformace genetická MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hmyzí proteiny MeSH
• silk proteinase inhibitor 2, Galleria mellonella MeSH Prohlížeč
• subtilisin MeSH

In this study, evidence is provided on the formation of hydrogen peroxide (H(2)O(2)) and hydroxyl radical (HO) in the potato tuber during the necrotrophic phase of the hemibiotrophic pathogen Phytophthora infestans infection. Using 3,3-diaminobenzidine tetrahydrochloride (DAB) imaging technique, the formation of H(2)O(2) was demonstrated in P. infestans-infected potato tuber. For the first time, HO formation was demonstrated in P. infestans-infected potato tuber using electron paramagnetic resonance (EPR) spectroscopy. An enhancement in spontaneous ultra-weak photon emission indicated the extent of lipid peroxidation in the P. infestans-infected potato tuber. The data presented in this study reveal that the formation of H(2)O(2) and HO in the P. infestans-infected potato tuber is associated with lipid peroxidation. It is proposed here that the ultra-weak photon emission can be used as a non-invasive indicator of the oxidative processes in the quality control at food industry.

• MeSH
• hydroxylový radikál metabolismus   MeSH
• kvalita jídla MeSH
• molekulární zobrazování MeSH
• nemoci rostlin parazitologie   MeSH
• peroxid vodíku metabolismus   MeSH
• peroxidace lipidů MeSH
• Phytophthora infestans růst a vývoj   fyziologie   MeSH
• Solanum tuberosum metabolismus   parazitologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hydroxylový radikál MeSH
• peroxid vodíku MeSH

The level of adipokinetic hormones (AKHs) (Peram-CAH-I and II) in the corpora cardiaca and the hemolymph of Leptinotarsa decemlineata enormously increases in the adults fed on genetically modified potatoes containing either GNA lectin or Cry 3Aa toxin concomitant with increased oxidative stress in gut tissues. A similar enhancement of the AKH titer is achieved when the adults are injected with paraquat that evokes oxidative stress. On the other hand, an injection of exogenous AKH reduces oxidative stress biomarkers in the hemolymph by reducing protein carbonyls and enhancing reduced glutathione levels. These facts indicate that there is a feedback regulation between an oxidative stressor action and the level of AKH in the insect body, and that AKHs might be involved in the activation of an antioxidant protection mechanism. These results are to our knowledge, the first evidence for the involvement of AKHs in oxidative stress mitigation, in addition to a plethora of other roles.

• MeSH
• bakteriální toxiny genetika   MeSH
• brouci metabolismus   MeSH
• ELISA MeSH
• geneticky modifikované rostliny MeSH
• hemolymfa metabolismus   MeSH
• hmyzí hormony metabolismus   MeSH
• kyselina pyrrolidonkarboxylová analogy a deriváty   metabolismus   MeSH
• lektiny vázající mannosu genetika   MeSH
• oligopeptidy metabolismus   MeSH
• oxidační stres * MeSH
• paraquat farmakologie   MeSH
• posttranslační úpravy proteinů účinky léků   MeSH
• rostlinné lektiny genetika   MeSH
• Solanum tuberosum genetika   parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adipokinetic hormone MeSH Prohlížeč
• bakteriální toxiny MeSH
• hmyzí hormony MeSH
• kyselina pyrrolidonkarboxylová MeSH
• lektiny vázající mannosu MeSH
• oligopeptidy MeSH
• paraquat MeSH
• rostlinné lektiny MeSH
• snowdrop lectin MeSH Prohlížeč

Application of Bacillus thuringiensis tenebrionis (Bt) and expression of the Bt protein Cry3Aa in genetically modified crops are used for targeted control of the Colorado potato beetle Leptinotarsa decemlineata (Say). The Cry3A proteins are selectively toxic for the beetles but the present study describes effects of Cry3Aa on the Egyptian armyworm, Spodoptera littoralis (Boisduval). Cry3Aa expressed in potatoes or added to an agar-base wheat-germ diet reduced the growth of S. littoralis caterpillars and the fertility of adults. The effect of 1.4 mg kg(-1) Cry3Aa in potato leaves was comparable with that of 3.3 mg kg(-1) in the diet. This difference in activity was correlated with better digestibility and higher conversion efficiency of the diet that also supported higher reproduction rate: S. littoralis grown on the potatoes reached a similar size to those on the diet but laid only 702 instead of 1077 eggs per female. Cry3Aa consumption reduced body growth as a consequence of lower food intake without significantly affecting food digestibility and the conversion efficiency of nutrients. The 11% and 5% body weight reductions caused by 1.4 mg kg(-1) Cry3Aa in potatoes and 3.3 mg kg(-1) in the diet, respectively, were associated with 74% and 65% reduction in the number of progeny; S littoralis grown on a diet with 9.1 mg kg(-1) Cry3Aa were 10% smaller and produced no viable progeny. These data suggest that the curtailment of reproduction was not caused by a general shortage of nutrient reserves but by a more direct Cry3Aa effect on the reproduction process.

• MeSH
• Bacillus thuringiensis MeSH
• bakteriální proteiny toxicita   MeSH
• bakteriální toxiny toxicita   MeSH
• biologická kontrola škůdců * MeSH
• endotoxiny toxicita   MeSH
• geneticky modifikované rostliny MeSH
• hemolyziny MeSH
• insekticidy toxicita   MeSH
• larva účinky léků   MeSH
• Solanum tuberosum genetika   parazitologie   MeSH
• Spodoptera účinky léků   růst a vývoj   MeSH
• stravovací zvyklosti MeSH
• toxiny Bacillus thuringensis MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bakteriální proteiny MeSH
• bakteriální toxiny MeSH
• endotoxiny MeSH
• hemolyziny MeSH
• insecticidal crystal protein, Bacillus Thuringiensis MeSH Prohlížeč
• insekticidy MeSH
• toxiny Bacillus thuringensis MeSH