Expanding the knowledge about Leishmania species in wild mammals and dogs in the Brazilian savannah

Background: Wild, synanthropic and domestic mammals act as hosts and/or reservoirs of several Leishmania spp. Studies on possible reservoirs of Leishmania in different areas are fundamental to understand host-parasite interactions and develop strategies for the surveillance and control of leishmaniasis. In the present study, we evaluated the Leishmania spp. occurrence in mammals in two conservation units and their surroundings in Brasília, Federal District (FD), Brazil. Methods: Small mammals were captured in Brasília National Park (BNP) and Contagem Biological Reserve (CBR) and dogs were sampled in residential areas in their vicinity. Skin and blood samples were evaluated by PCR using different molecular markers (D7 24Sα rRNA and rDNA ITS1). Leishmania species were identified by sequencing of PCR products. Dog blood samples were subjected to the rapid immunochromatographic test (DPP) for detection of anti-Leishmania infantum antibodies. Results: 179 wild mammals were studied and 20.1% had Leishmania DNA successfully detected in at least one sample. Six mammal species were considered infected: Clyomys laticeps, Necromys lasiurus, Nectomys rattus, Rhipidomys macrurus, Didelphis albiventris and Gracilinanus agilis. No significant difference, comparing the proportion of individuals with Leishmania spp., was observed between the sampled areas and wild mammal species. Most of the positive samples were collected from the rodent N. lasiurus, infected by L. amazonensis or L. braziliensis. Moreover, infections by Trypanosoma spp. were detected in N. lasiurus and G. agilis. All 19 dog samples were positive by DPP; however, only three (15.8%) were confirmed by PCR assays. DNA sequences of ITS1 dog amplicons showed 100% identity with L. infantum sequence. Conclusions: The results suggest the participation of six species of wild mammals in the enzootic transmission of Leishmania spp. in FD. This is the first report of L. amazonensis in N. lasiurus

Correction: Genome-wide identification, characterization and expression profile analysis of expansins gene family in sugarcane (Saccharum spp.).

[This corrects the article DOI: 10.1371/journal.pone.0191081.]

Fitosociología de malas hierbas en frijol caupí cultivado sobre rastrojos de diferentes plantas de cobertura

Cover stubble in the zero tillage system benefits weed control. However, the influence of different cover crops on their composition and diversity in cowpea cultivation is little known. This study investigates the phytosociology, diversity and equity indices, control, similarity and beta diversity of weeds in cowpea cultivation managed on different cover crops. The experiment was carried out in a completely randomized block design, in a split plot scheme, with four repetitions. The plots were made up of straw from cover plants: spontaneous vegetation (T1), brachiaria (T2), millet (T3), sunn hemp (T4), jack beans (T5), brachiaria+crotalaria (T6), brachiaria+pig beans (T7), millet+crotalaria (T8), millet+pig beans (T9) and black mucuna (T10). The subplots were made up of treatments with and without weeding. The species Tridax procumbens, Digitaria horizontalis and Digitaria insularis were the most important species in the phytosociological study. The treatments changed the number of individuals and the diversity and equitability indices. In weeding management, T6 and T8 coverage showed greater diversity, while T9 showed greater evenness. Without weeding, T2 and T6 had fewer individuals and greater diversity, however, T8 and T9 showed greater evenness. Cover crops showed differences in weed suppression efficiency in weed-treated areas. However, brachiaria cultivation stood out as one of the most efficient for controlling these weeds. The similarity and beta diversity of weeds varied between treatments.Los rastrojos de cobertura en el sistema de labranza cero, beneficia el control de malas hierbas. Sin embargo, la influencia de los diferentes cultivos de cobertura en la composición y la diversidad de éstas en el cultivo del caupí es poco conocida. Este estudio investiga la fitosociología, los índices de diversidad y equidad, control, similitud y diversidad beta de las malas hierbas en el cultivo de caupí manejado sobre diferentes cultivos de cobertura. El experimento se llevó a cabo en diseño de bloques completamente al azar, en esquema de parcelas divididas, con cuatro repeticiones. Las parcelas estaban constituidas por rastrojos de plantas de cobertura: vegetación espontánea (T1), brachiaria (T2), mijo (T3), crotalaria (T4), frijol canavalia (T5), brachiaria+crotalaria (T6), brachiaria+frijol canavalia (T7), mijo+crotalaria (T8), mijo+frijol canavalia (T9), mucuna negra (T10). Las subparcelas estaban constituidas por los tratamientos de manejo con y sin deshierbe mecánico. Las especies Tridax procumbens, Digitaria horizontalis y Digitaria insularis fueron las especies más importantes en el estudio fitossociológico. Los tratamientos cambiaron el número de individuos y los índices de diversidad y equidad. En el manejo de malezas, la cobertura T6 y T8 mostró mayor diversidad, mientras que T9 mostró mayor equidad.  Sin deshierbe, T2 y T6 tuvieron un menor número de individuos y mayor diversidad, pero T8 y T9 mostraron mayor equidad. Los cultivos de cobertura presentaron diferencias en la eficiencia de la supresión de malas hierbas en las áreas tratadas con deshierbe. Sin embargo, el cultivo de brachiaria se destacó como uno de los más eficientes para el control de estas malas hierbas. La similitud y diversidad beta de las malezas varió entre los tratamientos

Productividad y calidad fisiológica de semillas de plantas de frijol sometidas a desecación por herbicidas en diferentes etapas fenológicas

The use of herbicides in the pre-harvest of cowpea beans seeks to increase the uniformity of maturation of plants and pods. The objective of this work was to evaluate the productivity and physiological quality of bean seeds in plants subjected to desiccation promoted by herbicides applied in two phenological stages. Two experiments were conducted, in field and laboratory. In the field, a randomized block design was developed in a factorial scheme (3x2+1). Diquat (2 L·ha-1), flumioxazin (60 g·ha-1), and the mixture of both products (di-flu) were used in two phenological stages of application (80 and 90 % of the mature pods), repeated four times. A control treatment (without herbicide) was included. In the field, productivity and performance variables were evaluated. In the laboratory, the physiological quality of the seeds was evaluated. Herbicides applied with 80 % and 90 % mature pods did not influence grain yield. Diquat and di-flu anticipated harvest in six days without affecting bean yield. The desiccation with 90 % of ripe pods positively influenced the quality of seed. The application of the herbicide to the plants in the phenological stage of 80 % of mature pods negatively influences the quality of the bean seed.El uso de herbicidas en la pre-cosecha de frijol procura aumentar la uniformidad de maduración de plantas y vainas. El objetivo de este trabajo fue evaluar la productividad y calidad fisiológica de la semilla en plantas de frijol sometidas a desecación promovida por herbicidas aplicados en dos etapas fenológicas. Fueron conducidos dos experimentos tanto en campo como en laboratorio. En campo se instaló un diseño de bloques al azar en esquema factorial (3x2+1). Fue utilizado diquat (2 L·ha-1), flumioxazin (60 g·ha-1) y la mezcla de ambos (di-flu) en dos etapas fenológicas de la planta (80 y 90 % de las vainas maduras), además de un tratamiento control (sin herbicida), todo repetido cuatro veces. Se evaluaron variables de productividad y rendimiento. En laboratorio, se evaluó la calidad fisiológica de las semillas. Los herbicidas aplicados con 80 % y 90 % de vainas maduras no influyeron en el rendimiento del grano. Diquat y di-flu anticiparon la cosecha en seis días sin afectar el rendimiento del frijol. La desecación con 90 % de las vainas maduras influyó positivamente en la calidad de la semilla. La aplicación del herbicida a las plantas en la etapa fenológica de 80 % de vainas maduras influye negativamente en la calidad de la semilla del frijol

Interferencia de Cenchrus echinatus y Rottboellia exaltata en el crecimiento del frijol caupí

Cowpea is an important crop for the food security of the world population. However, their production is constantly affected by weed interferences. The objective of this research was to determine the effect of two different weeds at different densities of competition on the growth characteristics of the crop. The study was conducted using a randomized block design in a factorial arrangement of the treatments (2x4 for analysis in cowpea, and 2x3 for weeds). The weed species (Cenchrus echinatus and Rottboellia exaltata) and four competition densities (zero, two, four, and six individuals per pot), with four repetitions, were studied at the crop flowering stage. We measured leaf area, leaf and stem dry mass, root dry mass (RDM), dry mass of the aerial part (DMAP), total dry mass, and the ratio (RDM/DMAP); additionally, the dry mass of the aerial part and root (DMAW and DMRW) of the weeds was measured. The increase in the density of the weeds resulted in a decrease in the values ​​of all the variables of the crop. In the case of weeds, C. echinatus showed higher DMAW than R. exaltata although there were no differences in DMRW. Both weeds negatively affect the growth of bean plants, though with C. echinatus the effect is even greater. The interference effect is higher as the density of the weeds increases.El frijol caupí es un cultivo importante para la seguridad alimentaria de la población mundial; sin embargo, su producción es afectada constantemente por la interferencia de las malezas. El objetivo de esta investigación fue determinar el efecto de la interferencia de las malezas en diferentes densidades de competencia sobre las características de crecimiento del cultivo. El estudio fue conducido mediante diseño de bloques al azar en arreglo factorial 2x4 para análisis del cultivo y 2x3 para las malezas. Fueron estudiadas dos especies de maleza (Cenchrus echinatus y Rottboellia exaltata) y cuatro intensidades de competencia (cero, dos, cuatro y seis individuos por maceta), con cuatro repeticiones. Las evaluaciones fueron realizadas en la etapa de floración del cultivo y las variables medidas fueron área foliar, masa seca de las hojas, del tallo, de la raíz (MSR), de la parte aérea (MSPA), masa seca total y la relación MSR/MSPA. Además, fueron cuantificadas en las malezas la masa seca de la parte aérea (MSPAM) y de la raíz (MSRM). El aumento de la densidad de competencia de las malezas resultó en disminución de los valores de todas las variables analizadas en el cultivo. En las malezas, C. echinatus mostró mayor MSPAM que R. exaltata, aunque no hubo diferencias en MSRM. Ambas malezas afectan negativamente el crecimiento de las plantas de frijol, aunque con C. echinatus el efecto es aún mayor. El efecto de interferencia es mayor a medida que aumenta la densidad de las malezas

Citrus aurantium L. essential oil exhibits anxiolytic-like activity mediated by 5-HT1A-receptors and reduces cholesterol after repeated oral treatment

BACKGROUND: The current treatments for anxiety disorders and depression have multiple adverse effects in addition to a delayed onset of action, which has prompted efforts to find new substances with potential activity in these disorders. Citrus aurantium was chosen based on ethnopharmacological data because traditional medicine refers to the Citrus genus as useful in diminishing the symptoms of anxiety or insomnia, and C. aurantium has more recently been proposed as an adjuvant for antidepressants. In the present work, we investigated the biological activity underlying the anxiolytic and antidepressant effects of C. aurantium essential oil (EO), the putative mechanism of the anxiolytic-like effect, and the neurochemical changes in specific brain structures of mice after acute treatment. We also monitored the mice for possible signs of toxicity after a 14-day treatment. METHODS: The anxiolytic-like activity of the EO was investigated in a light/dark box, and the antidepressant activity was investigated in a forced swim test. Flumazenil, a competitive antagonist of benzodiazepine binding, and the selective 5-HT(1A) receptor antagonist WAY100635 were used in the experimental procedures to determine the mechanism of action of the EO. To exclude false positive results due to motor impairment, the mice were submitted to the rotarod test. RESULTS: The data suggest that the anxiolytic-like activity observed in the light/dark box procedure after acute (5 mg/kg) or 14-day repeated (1 mg/kg/day) dosing was mediated by the serotonergic system (5-HT(1A) receptors). Acute treatment with the EO showed no activity in the forced swim test, which is sensitive to antidepressants. A neurochemical evaluation showed no alterations in neurotransmitter levels in the cortex, the striatum, the pons, and the hypothalamus. Furthermore, no locomotor impairment or signs of toxicity or biochemical changes, except a reduction in cholesterol levels, were observed after treatment with the EO. CONCLUSION: This work contributes to a better understanding of the biological activity of C. aurantium EO by characterizing the mechanism of action underlying its anxiolytic-like activity