ABSTRACT
Soybean is the most important oilseed cultivated in the world and Brazil is the second major producer. Expansion of soybean cultivation has direct and indirect impacts on natural habitats of high conservation value, such as the Brazilian savannas (Cerrado). In addition to deforestation, land conversion includes the use of fertilizers and pesticides and can lead to changes in the soil microbial communities. This study evaluated the soil bacterial and fungal communities and the microbial biomass C in a native Cerrado and in a similar no-tillage soybean monoculture area using PCR-DGGE and sequencing of bands. Compared to the native area, microbial biomass C was lower in the soybean area and cluster analysis indicated that the structure of soil microbial communities differed. 16S and 18S rDNA dendrograms analysis did not show differences between row and inter-row samples, but microbial biomass C values were higher in inter-rows during soybean fructification and harvest. The study pointed to different responses and alterations in bacterial and fungal communities due to soil cover changes (fallow x growth period) and crop development. These changes might be related to differences in the pattern of root exudates affecting the soil microbial community. Among the bands chosen for sequencing there was a predominance of actinobacteria, y-proteobacteria and ascomycetous divisions. Even under no-tillage management methods, the soil microbial community was affected due to changes in the soil cover and crop development, hence warning of the impacts caused by changes in land use.
Subject(s)
Biomass , Fertilizers , Fungi , In Vitro Techniques , Pest Control, Biological , Polymerase Chain Reaction , Soil Microbiology , Glycine max , Food Samples , Methods , MethodsABSTRACT
The effects of olanzapine (OLZ) on the viability and functioning of human polymorphonuclearcells (PMNs) are clearly opposite to those previously reported forclozapine (CLZ). In fact, after 4- or 24-h-treatment with 20-50 μM OLZ, a significant inhibition of the respiratory burst in PMNs activated with opsonized zimosanor phorbol myristate acetate (PMA) was observed, whereas the burst provoked byformyl-methionyl-leucyl-phenylalanine (fMLP) was only inhibited at 50 μM OLZ.Under the same conditions, spontaneous apoptosis was accelerated at 20-50 μMOLZ, while the exogenous addition of H2O2 resulted in the PMN apoptosis beingdose-dependently inhibited by OLZ in the entire range of concentrations. However,when H2O2 was intracellularly generated by treatment with PMA, the induced apoptosis was only decreased at 2 μM OLZ. Absorbance scans revealed that OLZis able to react with equimolar quantities of either H2O2 or HOCl. These results suggest that OLZ inhibits both ROS-induced PMN apoptosis and respiratory burst due to extracellular scavenging of released ROS.
Los efectos de olanzapine (olz) sobre la viabilidad y el funcionamiento de células humanas polimorfonucleares (pmn, por sus siglas en inglés) claramente son opuestosa los señalados para la clozapine (clz). En efecto, después de 4-24 h de tratamiento con 20-50 μM olz, se observó una inhibición significativa del estallido respiratorio en pmn activados con zimosan o con forbol acetato miristato, mientras que la inhibición provocada por el formil-metionil-leucil-fenilalanina fue sólo inhibida a 50μM de olz. En las mismas condiciones, la apoptosis espontánea se aceleró con 20-50μM olz, mientras que la adición exógena de H2O2 dio lugar a la apoptosis de pmn en dosis dependiente inhibida por olz en el rango entero de concentraciones. Sin embargo, cuando se generó H2O2 intracelular por tratamiento con pma, la apoptosis inducida se disminuyó solamente con 2 μM olz. Las exploraciones de los espectros de absorbancia revelaron que olz puede reaccionar con cantidades equimolares de H2O2 o de HOCL. Estos resultados sugieren que olz inhibe ambos tipos de apoptosis de pmn (la inducida por especies reactivas oxigenadas y por estallido respiratorio debido a atrapadores extracelulares de estas especies reactivas oxigenadas).