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981.
Ripening in papaya fruit is altered by ACC oxidase cosuppression 总被引:2,自引:0,他引:2
López-Gómez R Cabrera-Ponce JL Saucedo-Arias LJ Carreto-Montoya L Villanueva-Arce R Díaz-Perez JC Gómez-Lim MA Herrera-Estrella L 《Transgenic research》2009,18(1):89-97
Papaya (Carica papaya) is a very important crop in many tropical countries but it is highly susceptible to parasitic diseases, physiological disorders,
mechanical damage and fruit overripening. Here we report a study on ACC oxidase cosuppression and its effects on papaya fruit
ripening. Papaya ACC oxidase was isolated using PCR and embriogenic cells transformed by biolistic using the CaMV 35S promoter
to drive the expression of the PCR fragment in sense orientation. Fifty transgenic lines were recovered and 20 of those were
grown under field conditions. Southern analysis showed incorporation of the transgene in different copy numbers in the papaya
genome. Fruits were evaluated in terms of texture (firmness), colour development, respiration and ethylene production. A sharp
reduction in ethylene and CO2 production was detected, whereas softening and colour development of the peel were also altered.
Overall, transgenic fruits showed a delay in ripening rate. A reduction in mRNA level for ACC oxidase in transgenic fruit
was clearly detectable by northern blot. More studies are necessary before this technology can be used to extend the shelf
life of papaya fruit. 相似文献
982.
Alejandra Gerpe Guzmn lvarez Diego Benítez Lucía Boiani Martín Quiroga Paola Hernndez Maximiliano Sortino Susana Zacchino Mercedes Gonzlez Hugo Cerecetto 《Bioorganic & medicinal chemistry》2009,17(21):7500-7509
Chagas disease represents a serious public health problem in South America. The first line of treatment is Nifurtimox and Benznidazole which generate toxic effects in treated patients. We have recently shown that a number of 5-nitrofuranes possess activity against Trypanosoma cruzi through oxidative stress and inhibition of parasite ergosterol biosynthesis, specifically at the level of squalene epoxidase. Here, we identify new 5-nitrofuranes and the thia-analogues with excellent effects on the viability of T. cruzi and adequate parasite/mammal selectivity indexes. Analysis of the free sterols from parasite incubated, during 120 h, with the compounds showed that some of them accumulated squalene suggesting the squalene epoxidase activity inhibition of the parasite. Nifurtimox was able to accumulate squalene only at lower incubation times. Due to this fact some derivatives were also tested as antifungal agents. Quantitative structure–activity relationship studies were also performed showing relevant features for further new derivatives design. Taken together, the results obtained in the present work point to a more general effect of 5-nitrofuranes and 5-nitrothiophenes in trypanosomatids, opening potential therapeutic possibilities of them for these infectious diseases. 相似文献
983.
Angela M. Rizzo Gigliola Montorfano Manuela Negroni Paola Corsetto Patrizia Berselli Paola Marciani Stefania Zava Bruno Berra 《Cell biology international》2009,33(8):893-898
Space flights cause a number of patho-physiological changes. Oxidative damage has been demonstrated in astronauts after space flights. Oxidative stress is due to an imbalance between production of oxidant and antioxidative defence. In embryos of Xenopus laevis, the glutathione system is an inducible antioxidant defence. For this reason, we investigated the effect of gravity deprivation on endogenous antioxidant enzymes in X. laevis embryos developed for 6 days in a Random Positioning Machine. The results show that glutathione content and the activity of antioxidant enzymes increase in RPM embryos, suggesting the presence of a protective mechanism. An induction of antioxidant defence might play an important role for animals to adapt to micro-gravitational stress, possibly during actual space flights. 相似文献
984.
David Hasen?hrl Attilio Fabbretti Paola Londei Claudio O. Gualerzi Udo Bl?si 《RNA (New York, N.Y.)》2009,15(12):2288-2298
The function of initiation factors in and the sequence of events during translation initiation have been intensively studied in Bacteria and Eukaryotes, whereas in Archaea knowledge on these functions/processes is limited. By employing chemical probing, we show that translation initiation factor aIF1 of the model crenarchaeon Sulfolobus solfataricus binds to the same area on the ribosome as the bacterial and eukaryal orthologs. Fluorescence energy transfer assays (FRET) showed that aIF1, like its eukaryotic and bacterial orthologs, has a fidelity function in translation initiation complex formation, and that both aIF1 and aIF1A exert a synergistic effect in stimulating ribosomal association of the Met-tRNAiMet binding factor a/eIF2. However, as in Eukaryotes their effect on a/eIF2 binding appears to be indirect. Moreover, FRET was used to analyze for the first time the sequence of events toward translation initiation complex formation in an archaeal model system. These studies suggested that a/eIF2-GTP binds first to the ribosome and then recruits Met-tRNAiMet, which appears to comply with the operational mode of bacterial IF2, and deviates from the shuttle function of the eukaryotic counterpart eIF2. Thus, despite the resemblance of eIF2 and a/eIF2, recruitment of initiator tRNA to the ribosome is mechanistically different in Pro- and Eukaryotes. 相似文献
985.
Andrea Paola Albicócco 《Journal of invertebrate pathology》2009,101(3):210-214
The bionomics of South American strains of Ascogregarina spp. are poorly known and the first studies were performed a few years ago. Our main objective was to characterize Ascogregarina culicis population in Aedes aegypti immatures in temperate Argentina. A total of 1800 water-filled containers were inspected within a cemetery of Buenos Aires City through a reproductive period of the host (October 2006-June 2007). The parasite was detected in 16.7% (329/1974) of the immatures and 8.5% (15/177) of the breeding sites. The prevalence decreased from 19.9% in larvae to 6.5% in pupae. In those infected breeding sites, about 85% of the immature mosquitoes harbor the parasite with a median intensity of nine trophozoites per larva and six gametocysts per pupa. The prevalence in shaded containers was higher than in sun exposed ones but the intensity of the infection was quite similar between both lighting conditions. Sun-exposed containers recorded water temperatures significantly higher than those under shade throughout the study period. Parasite trophozoites were only found from January to May with a clear seasonal pattern of prevalence. Monthly values of parasite prevalence and mosquito host (percentage of breeding sites and number of immatures) were significantly correlated at p < 0.05 when a temporal delay of two months was considered. Our results suggest that parasite prevalence is spatially and temporally heterogeneous in temperate urban Argentina, and these variations are associated with the host abundance. 相似文献
986.
Rubén E. Varela M Diana Lorena Muñoz Sara M. Robledo Bala K. Kolli Kwang Poo Chang 《Experimental parasitology》2009,122(2):134-139
Promastigotes of Leishmania (Viannia) panamensis were successfully transfected with p6.5-egfp to express green fluorescent protein. The transfectants remained infective to macrophages, providing an in vitro model for screening antileishmanial drugs. This was demonstrated by flow cytometry of macrophage-associated GFP after exposure of infected cultures to known antileishmanial drugs, i.e. amphotericin B and glucantime®. Fluorescence of GFP diminished progressively from infected cells with increasing drug concentrations used in both cases. The availability of this fluorescent assay for infection of macrophages by L. (V.) panamensis facilitates drug discovery program for the Viannia species, which differ significantly from those of the Leishmania subgenus. 相似文献
987.
Valentino Di Donato Paola Esposito Debora Naimo Mauro Caffau Antonino Greco 《Geobios》2009,42(5):561-82
The palaeontological, geochemical and mineralogical records of core GNS84-C106 were analysed in order to reconstruct palaeohydrological changes and palaeoproductivity patterns in the Gulf of Salerno for the last 34 kyr. This approach, including compositional analysis of planktonic and benthic assemblages, gave an insight into the relationships between continental, sea surface and bottom environmental changes. The main source of variability of planktonic and benthic assemblages is related respectively to sea surface temperature and palaeobathymetry. Interrelated changes in surface salinity, nutrients, density gradient in the water column and organic fluxes at the bottom act as a secondary factor controlling the composition of both planktonic and benthic assemblages. The highest palaeoproductivity rates were reached during an interval spanning from late glacial to Middle Holocene, in conditions of enhanced continental run-off. During the Early and Middle Holocene, reduced surface salinity and density stratification were also coupled with the development of a deep chlorophyll maximum and enhanced flux or organic matter at the bottom. From about 6.5 kyr B.P. onward, a sharp reduction in palaeoproductivity took place, coupled with an increase in surface salinities. 相似文献
988.
989.
990.
Anna M. Mileo Claudia Abbruzzese Stefano Mattarocci Emanuele Bellacchio Paola Pisano Antonio Federico Vittoria Maresca Mauro Picardo Alessandra Giorgi Bruno Maras M. Eugenia Schininà Marco G. Paggi 《PloS one》2009,4(10)