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81.
Jorge Angelini Ghio Silvina Tania Taurian Fernando Ibáñez María Laura Tonelli Lucio Valetti María Soledad Anzuay Liliana Ludueña Vanina Muñoz Adriana Fabra 《Archives of microbiology》2013,195(10-11):683-692
In the peanut production, the applications of herbicides and fungicides are a common practice. In this work, studies done under field conditions demonstrated that pesticides affected negatively the number and nitrogenase activity of diazotrophic populations of soil. Agrochemical effects were not transient, since these parameters were not recovered to pre-treatment levels even 1 year after pesticides application. Results obtained from greenhouse experiments revealed that the addition of herbicide or fungicides diminished the free-living diazotrophs number reaching levels found in soil amended with the pesticides and that the number of symbiotic diazotrophs was not affected by the insecticide assayed. The soil nitrogenase activity was not affected by fungicides and glyphosate. The effect of pesticides on the nitrogen-fixing bacteria diversity was evaluated both in field and greenhouse experiments. Analysis of clone libraries generated from the amplification of soil nifH gene showed a diminution in the genetic diversity of this bacterial community. 相似文献
82.
83.
Rocheli de Souza Anelise Beneduzi Adriana Ambrosini Pedro Beschoren da Costa Jacqueline Meyer Luciano K. Vargas Rodrigo Schoenfeld Luciane M. P. Passaglia 《Plant and Soil》2013,366(1-2):585-603
Background and Aims
Several strains of rhizobacteria may be found in the rhizospheric soil, on the root surface or in association with rice plants. These bacteria are able to colonize plant root systems and promote plant growth and crop yield through a variety of mechanisms. The objectives of this study were to isolate, identify, and characterize putative plant growth-promoting rhizobacteria (PGPR) associated with rice cropped in different areas of southern Brazil.Methods
Bacterial strains were selectively isolated based on their growth on three selective semi-solid nitrogen-free media. Bacteria were identified at the genus level by PCR-RFLP 16S rRNA gene analysis and partial sequencing methodologies. Bacterial isolates were evaluated for their ability to produce indolic compounds and siderophores and to solubilize phosphate. In vitro biological nitrogen fixation and the ability to produce 1-aminocyclopropane-1-carboxylate deaminase were evaluated for each bacterial isolate used in the inoculation experiments.Results
In total, 336 bacterial strains were isolated representing 31 different bacterial genera. Strains belonging to the genera Agrobacterium, Burkholderia, Enterobacter, and Pseudomonas were the most prominent isolates. Siderophore and indolic compounds producers were widely found among isolates, but 101 isolates were able to solubilize phosphate. Under gnotobiotic conditions, eight isolates were able to stimulate the growth of rice plants. Five of these eight isolates were also field tested in rice plants subjected to different nitrogen fertilization rates.Conclusions
The results showed that the condition of half-fertilization plus separate inoculation with the isolates AC32 (Herbaspirillum sp.), AG15 (Burkholderia sp.), CA21 (Pseudacidovorax sp.), and UR51 (Azospirillum sp.) achieved rice growth similar to those achieved by full-fertilization without inoculation, thus highlighting the potential of these strains for formulating new bioinoculants for rice crops. 相似文献84.
Gladys I. Galende Adriana Troncoso Sergio A. Lambertucci 《Studies on Neotropical Fauna and Environment》2013,48(1):32-39
We assessed diet selection, impact on vegetation, and explored habitat relationships with marsh birds of coypus (Myocastor coypus) in a steppe lagoon in Argentinean Patagonia. In two consecutive springs, abundance and spatial use of the coypus and nesting marsh birds were estimated by direct counts. The coypu was a selective consumer with seasonal variations in food items, and Myriophyllum sp. and Schoenoplectus californicus dominated its diet. Coypus and marsh birds showed a differential spatial use when rushes cover was high. However, when rushes cover decreased by coypu browsing, there was a similar use of space, and marsh birds were displaced to nest on the open water and other poorly protected areas of the rushes. Our results suggest that high abundances of coypu can have a detrimental effect on wetland ecosystems. Systematic monitoring and evaluation of their effects on wetlands in recently colonized areas is recommended. 相似文献
85.
Sally E. Thomas Elke Malzer Adriana Ordó?ez Lucy E. Dalton Emily F. A. van ′t Wout Elizabeth Liniker Damian C. Crowther David A. Lomas Stefan J. Marciniak 《The Journal of biological chemistry》2013,288(11):7606-7617
Cell cycle checkpoints ensure that proliferation occurs only under permissive conditions, but their role in linking nutrient availability to cell division is incompletely understood. Protein folding within the endoplasmic reticulum (ER) is exquisitely sensitive to energy supply and amino acid sources because deficiencies impair luminal protein folding and consequently trigger ER stress signaling. Following ER stress, many cell types arrest within the G1 phase, although recent studies have identified a novel ER stress G2 checkpoint. Here, we report that ER stress affects cell cycle progression via two classes of signal: an early inhibition of protein synthesis leading to G2 delay involving CHK1 and a later induction of G1 arrest associated both with the induction of p53 target genes and loss of cyclin D1. We show that substitution of p53/47 for p53 impairs the ER stress G1 checkpoint, attenuates the recovery of protein translation, and impairs induction of NOXA, a mediator of cell death. We propose that cell cycle regulation in response to ER stress comprises redundant pathways invoked sequentially first to impair G2 progression prior to ultimate G1 arrest. 相似文献
86.
Erica Cirri Corinna Kirchner Simon Becker Adriana Katz Steven J. Karlish Hans-Jürgen Apell 《The Journal of membrane biology》2013,246(12):967-979
The human α1/His10-β1 isoform of Na,K-ATPase has been reconstituted as a complex with and without FXYD1 into proteoliposomes of various lipid compositions in order to study the effect of the regulatory subunit on the half-saturating Na+ concentration (K 1/2) of Na+ ions for activation of the ion pump. It has been shown that the fraction of negatively charged lipid in the bilayer crucially affects the regulatory properties. At low concentrations of the negatively charged lipid DOPS (<10 %), FXYD1 increases K 1/2 of Na+ ions for activation of the ion pump. Phosphorylation of FXYD1 by protein kinase A at Ser68 abrogates this effect. Conversely, for proteoliposomes made with high concentrations of DOPS (>10 %), little or no effect of FXYD1 on the K 1/2 of Na+ ions is observed. Depending on ionic strength and lipid composition of the proteoliposomes, FXYD1 can alter the K 1/2 of Na+ ions by up to twofold. We propose possible molecular mechanisms to explain the regulatory effects of FXYD1 and the influence of charged lipid and protein phosphorylation. In particular, the positively charged C-terminal helix of FXYD1 appears to be highly mobile and may interact with the cytoplasmic N domain of the α-subunit, the interaction being strongly affected by phosphorylation at Ser68 and the surface charge of the membrane. 相似文献
87.
Chronic coccidian infestation compromises flight feather quality in house sparrows Passer domesticus
Péter L. Pap Csongor I. Vágási Lőrinc Bărbos Attila Marton 《Biological journal of the Linnean Society. Linnean Society of London》2013,108(2):414-428
Parasites usurp indispensable resources for birds during a moult, and this is particularly relevant for those parasites residing in host intestines. This might compromise the nutritionally demanding moult and, thus, feather functionality. Although lower feather quality has profound and multifaceted adverse effects on residual fitness, surprisingly, little is known about parasites' effect on feather traits, especially over the longer term. We conducted an aviary experiment by medicating half of a group of naturally infested house sparrows Passer domesticus against intestinal coccidians for 15 months, spanning two consecutive postnuptial moults, whereas the other half was kept infested (i.e. without medication). Coccidian infestation significantly and negatively affected the size of the uropygial gland during the second moulting period compared to the medicated group. Furthermore, wing length was significantly shorter after the second moulting in the non‐medicated compared to the medicated female birds, which indicates that the negative effects of coccidians emerge only after a prolonged exposure to parasite infestation. Non‐medicated birds grew poorer quality flight feathers detected in a large number of feather traits both after the first and second moults. In the case of non‐medicated birds, the primaries were lighter and shorter, and had a smaller vane area, thinner rachis and decreased stiffness, although a higher barb and barbule density, which may have various consequences for fitness through reducing flight performance. Our findings demonstrate that, besides the well‐known immediate consequences for host breeding success, parasites might also have serious, long‐lasting effects through influencing feather quality and, ultimately, fitness of the host. © 2013 The Linnean Society of London 相似文献
88.
Adriana Fernanda Vizuete Daniela Fraga de Souza Maria Cristina Guerra Cristiane Batassini Márcio Ferreira Dutra Caren Bernardi Ana Paula Costa Carlos-Alberto Gonçalves 《Life sciences》2013,92(17-19):923-928
AimsWe investigated the effects of ketogenic diet (KD) on levels of tumor necrosis factor alpha (TNF-α, a classical pro-inflammatory cytokine), BDNF (brain-derived neurotrophic factor, commonly associated with synaptic plasticity), and S100B, an astrocyte neurotrophic cytokine involved in metabolism regulation.Main methodsYoung Wistar rats were fed during 8 weeks with control diet or two KD, containing different proportions of omega 6 and omega 3 polyunsaturated fatty acids. Contents of TNF-α, BDNF and S100B were measured by ELISA in two brain regions (hippocampus and striatum) as well as blood serum and cerebrospinal fluid.Key findingsOur data suggest that KD was able to reduce the levels of BDNF in the striatum (but not in hippocampus) and S100B in the cerebrospinal fluid of rats. These alterations were not affected by the proportion of polyunsaturated fatty acids offered. No changes in S100B content were observed in serum or analyzed brain regions. Basal TNF-α content was not affected by KD.SignificanceThese findings reinforce the importance of this diet as an inductor of alterations in the brain, and such changes might contribute to the understanding of the effects (and side effects) of KD in brain disorders. 相似文献
89.
Gabriel Capella Machado Daniela Vanessa Moris Thales Domingos Arantes Luciane Regina Franciscone Silva Raquel Cordeiro Theodoro Rinaldo P?ncio Mendes Adriana Pardini Vicentini Eduardo Bagagli 《Memórias do Instituto Oswaldo Cruz》2013,108(5):637-643
We aimed to evaluate whether the occurrence of cryptic species of
Paracoccidioides brasiliensis, S1, PS2, PS3 and
Paracoccidioides lutzii, has implications in the
immunodiagnosis of paracoccidioidomycosis (PCM). Small quantities of the antigen
gp43 were found in culture filtrates of P. lutzii strains and
this molecule appeared to be more variable within P. lutzii
because the synonymous-nonsynonymous mutation rate was lower, indicating an
evolutionary process different from that of the remaining genotypes. The
production of gp43 also varied between isolates belonging to the same species,
indicating that speciation events are important, but not sufficient to fully
explain the diversity in the production of this antigen. The culture filtrate
antigen AgEpm83, which was obtained from a PS3 isolate, showed large quantities
of gp43 and reactivity by immunodiffusion assays, similar to the standard
antigen (AgB-339) from an S1 isolate. Furthermore, AgEpm83 was capable of
serologically differentiating five serum samples from patients from the Botucatu
and Jundiaí regions. These patients had confirmed PCM but, were non-reactive to
the standard antigen, thus demonstrating an alternative for serological
diagnosis in regions in which S1 and PS2 occur. We also emphasise that it is not
advisable to use a single antigen preparation to diagnose PCM, a disease that is
caused by highly diverse pathogens. 相似文献
90.
Rosane Dias Costa Vanessa Amaral Mendon?a Frederico Marianetti Soriani Sandra Lyon Rachel Adriana Penido Ana Maria Duarte Dias Costa Marina Dias Costa Fabio de Souza Terra Mauro Martins Teixeira Carlos Mauricio de Figueiredo Antunes Antonio Lúcio Teixeira 《Memórias do Instituto Oswaldo Cruz》2013,108(8):1051-1056
Leprosy is an infectious and contagious spectral disease accompanied by a series of
immunological events triggered by the host response to the aetiologic agent,
Mycobacterium leprae . The induction and maintenance of the
immune/inflammatory response in leprosy are linked to multiple cell interactions and
soluble factors, primarily through the action of cytokines. The purpose of the
present study was to evaluate the serum levels of tumour necrosis factor (TNF)-α and
its soluble receptors (sTNF-R1 and sTNF-R2) in leprosy patients at different stages
of multidrug treatment (MDT) in comparison with non-infected individuals and to
determine their role as putative biomarkers of the severity of leprosy or the
treatment response. ELISA was used to measure the levels of these molecules in 30
healthy controls and 37 leprosy patients at the time of diagnosis and during and
after MDT. Our results showed increases in the serum levels of TNF-α and sTNF-R2 in
infected individuals in comparison with controls. The levels of TNF-α, but not
sTNF-R2, decreased with treatment. The current results corroborate previous reports
of elevated serum levels of TNF-α in leprosy and suggest a role for sTNF-R2 in the
control of this cytokine during MDT. 相似文献