Common Bean Productivity Following Diverse Boron Applications on Soil

Aspects related to micronutrients management are still poorly studied and need to be clarified to guarantee sustainable production. In this way, the study aimed to evaluate boron (B) fertilization effects on nutrition and production of common beans. The parameters measured were relative chlorophyll index, dry mass, boron transport, utilization and absorption efficiencies, B content, and B accumulation in plant tissues. The study showed that the dry mass production was negatively affected by B application, with linear dry mass decrease following the increase of B doses. Accordingly, it was found that the common bean cultivar Esplendor presented high absorption capacity of boron, and can reach 175 mg kg^?1. However, the high absorption caused phytotoxicity and reduced dry matter production by up to 30%, reflecting the efficiency of boron use by the plant, which was reduced in up to 75%.     

Adsorption Kinetics of Blue 5G Dye from Aqueous Solution on Dead Floating Aquatic Macrophyte: Effect of pH, Temperature, and Pretreatment

The textile industry is known to generate large quantities of effluents contaminated with dyes that are not fixed to the fibers during the dyeing process. The available technologies to remove these dyes from the wastewater are expensive and ineffective. Within this context, low-cost, easy-maintenance technologies for the removal of dyes have been studied, such as adsorption on aquatic macrophytes. Thus, the macrophyte Salvinia sp., raw or pretreated with NaOH or H₃PO₄, was used as biosorbent of Blue 5G reactive dye. The study showed that pH and temperature affect the dye removal capacity. The analysis of the infrared spectrum (FTIR) showed that chemical treatment of the Salvinia sp. modified the biomass surface and affected dye adsorption capacity. The pseudo-second-order kinetic model satisfactorily described the experimental data for raw and NaOH-pretreated biomass, and the pseudo-first-order model was more appropriate to describe the experimental data obtained with H₃PO₄-pretreated biomass. The highest capacity of Blue 5G dye removal was obtained with raw biomass, at 333?K and pH?1.0, with 98.35?% adsorption.     

Interaction of curcumin and bixin with β-cyclodextrin: complexation methods, stability, and applications in food

This work aimed to compare methods for the formation of complexes of bixin and curcumin with β-cyclodextrin (β-CD) and to evaluate the stability of the complexes formed by these methods and their food applications. The stoichiometric relationship between curcumin and β-CD was 1:2 and that between bixin and β-CD was 1:1. Curcumin-β-CD and bixin-β-CD complexes formed by kneading, coprecipitation, and simple mixing were evaluated by differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), or nuclear magnetic resonance (NMR-H). For both curcumin and bixin, the best method of complexation was coprecipitation. Complexation of colorants with β-CD promoted an intensification of color and increased water solubility; however, stabilization in the presence of light occurred only for bixin. Application of curcumin-β-CD in cheese and yogurt and bixin-β-CD in the curd did not alter the initial characteristics of the products, which were sensorialy well accepted. Therefore, the complexation of these natural colorants with β-CD favors their use in low-fat foods, broadening the field of industrial application.     

Effects of Fusicoccin and Vanadate on Proton Extrusion and Potassium Uptake by Rice

The effects of fusicoccin or vanadate on proton (H⁺) extrusion and potassium (K) uptake of four varieties of rice (oryza satiya L.) were studied. Two of them were improved varieties (IAC-47 and Agulha), with 70% genetic similarity. The two others were landraces (Bico Ganga and Piaui). Vanadate totally blocked H⁺-pumping activity while fusicoccin increased it. Potassium uptake was suppressed under vanadate but increased sharply under the fusicoccin treatment. The Piaui was the most affected by fusicoccin, while Agulha was the least affected. Under fusicoccin, Bico Ganga had a 48% increase in K uptake at the end of the experimental period in relation to the controls, while IAC-47 showed only a 17% increase. Taken together, for all varieties and treatments, there was a negative correlation between the final pH and the total K taken up by plants. This study suggests that some rice varieties need additional stimulation from external sources to express their full H⁺-pumping and K-uptake capabilities.     

Enzymes of Nitrogen Metabolism and Proteases Activity in Hairy Roots of Clover and Carrots,with and without Arbuscular Mycorrhizal Fungi

Hairy roots can be used for metabolic studies and also as a substrate for arbuscular mycorrhizal fungi (AMF). However, little is known about the behavior of these roots when infected with AMF. The metabolism of hairy roots grown with or without AMF, on two culture media, was investigated. An increase in protease activity was observed when the roots were cultured on medium with high nitrogen (N)-content. Glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH) activities increased along the development in both carrot and clover hairy roots. With the advancement of root senescence (at 132 d) a greater degradation of root tissue occurred, which was characterized by an increase in catabolic enzymes activity (proteases and GDH deamination). The results indicate that the glutamine synthetase/GOGAT pathway, characteristic of plant tissues, ceases to act in synchronism and is replaced by the GDH/GOGAT system under conditions of stress or senescence when excess ammonium is present.     

NITRATE UPTAKE KINETICS AND METABOLIC PARAMETERS IN TWO RICE VARIETIES GROWN IN HIGH AND LOW NITRATE

A study was conducted on the effect of nitrate (NO₃) levels on nitrate uptake kinetics and nitrogen (N) metabolism in two rice varieties, Piaui (landrace) and IAC-47 (improved). At 27 days after germination (DAG) N supply was suspended for 72 h, and then restored as 0.2 or 2 mM nitrate. The nitrate uptake kinetics was determined by the depletion method. Plants were harvested at 0, 6, and 24 h. Plants of the Piaui variety under 0.2 mM nitrate showed higher V_max and lower K_M, indicating higher efficiency of nitrate uptake at low supply. In the sheaths of both varieties, there was a greater accumulation of nitrate and lower activities of nitrate reductase and glutamine synthetase. The V-H⁺-ATPase activity increased between 0 and 6 h accompanying the nitrate influx, suggesting that the activity of this proton pump is necessary for the antiport activity (H⁺/2NO^? ₃) involved in the accumulation of nitrate into vacuoles.     

Azospirillum inoculation and nitrogen fertilization effect on grain yield and on the diversity of endophytic bacteria in the phyllosphere of rice rainfed crop

We assessed the Azospirillum inoculation and N-fertilization effect on grain yield and on the phyllosphere endophytic diversity of nitrogen-fixing bacteria in a rice rainfed crop. We used cultivation-based techniques and cultivation-independent methods involving PCR-16S rRNA and denaturing gradient gel electrophoresis (DGGE). In general, we observed that grain yield was improved when inoculated with Azospirillum (depending on the genotype) and/or fertilized with urea. A similar behavior was observed in total N-content in grain and the MPN determination, as the highest values occurred when seeds were inoculated with A. brasilense REC3 (S1) than with A brasilense 13-2C (S2). A positive nitrogenase activity and PCR-nifH amplification suggests that the bacteria associated to inner tissues of rice phyllosphere could have contributed to the different N-contents detected. The bacterial diversity, observed in the number and intensity of DGGE profiles, showed a higher number of bands when total DNA was obtained using only CTAB than with CTAB + PVP. The DGGE profiles revealed great stability in the dominating bands, which presumably represent numerically dominant species. Application of A. brasilense strains as inoculants did not influence the dominant members of the endophytic microbial communities in the phyllosphere, but improved N-content and production of rainfed rice crop.     

Fear erasure in mice requires synergy between antidepressant drugs and extinction training

Antidepressant drugs and psychotherapy combined are more effective in treating mood disorders than either treatment alone, but the neurobiological basis of this interaction is unknown. To investigate how antidepressants influence the response of mood-related systems to behavioral experience, we used a fear-conditioning and extinction paradigm in mice. Combining extinction training with chronic fluoxetine, but neither treatment alone, induced an enduring loss of conditioned fear memory in adult animals. Fluoxetine treatment increased synaptic plasticity, converted the fear memory circuitry to a more immature state, and acted through local brain-derived neurotrophic factor. Fluoxetine-induced plasticity may allow fear erasure by extinction-guided remodeling of the memory circuitry. Thus, the pharmacological effects of antidepressants need to be combined with psychological rehabilitation to reorganize networks rendered more plastic by the drug treatment.     

Standard area diagram set for assessment of severity and temporal progress of apple blotch

Apple blotch (Marssonina coronaria) is a foliar disease of increasing importance globally. Methods to quantify the disease and knowledge about epidemiology are required for new studies on the disease. The objectives of this study were to develop a standard area diagram set (SADs) to assess apple blotch severity and to describe the temporal progress of the disease under field conditions on older and younger leaves of two apple cultivars. For the development of SADs, symptomatic leaves were collected and scanned to obtain the actual severity. Based on the pattern of the disease, a SADs was elaborated and validated. Leaf severities were estimated without and with SADs by 12 raters to validate the tool. After validation, the SADs was used to assess apple blotch in older and younger leaves of selected shoots during the vegetative cycle of cvs. Eva and Gala. SADs severities ranged from 0.2 to 96%. Accuracy, precision, and reliability of the estimates were significantly improved when the SADs was used. In the field, the onset of apple blotch was in late spring and greater increases in severity occurred during summer. Rates of disease progress ranged from 0.09 to 0.13. Epidemics were different in older and younger leaves at the end of the apple vegetative cycle for both cultivars tested. Our work provided a tool for apple blotch quantification and described the disease progress curve under subtropical conditions, which can contribute as basis for future studies.