Eficiência de inoculantes comerciais de estirpes nativas de Rhizobium para seis leguminosas forrageiras em um solo de cerrado

A field experiment was carried out with the leumes Centrosema pubescens, Stylosanthes capitata, S. bracteata, Macroptilium atropurpureum, Galactia striata and Calopogonium mucunoides in a virgin cerrado soil in order to study the efficiency of commercial inoculants and of native Rhizobium strains. The statistical design was a complete factorial 3 x 6 in randomized blocks. The treatments were: a) check, b) inoculation and c) inoculation + 75 kg/ha N. The soil was not limed, but an additional treatment of 1 t/ha of lime was included with two of the legumes. The inoculation had no effect on the forage legumes studied except for the Centrosema pubescens, where inoculation increased the nodulation, dry weight and total N of the plants, compared to the check. The treatment receiving nitrogen was the best for C. pubescens, Macroptilium atropurpureum, Calopogonium mucunoider and Galactia striata indicating that symbiósis was not efficient in these species. Under the low soil fertility conditions of the experiment, the symbiosis with the native strains was sufficient to supply all the nitrogen necessary to Stylosanthes capitata and S. bracteata. The addition of lime to Centrosema pubescens and Stylosanthes capitata improved the nodulation, total N and dry weight of plants. The results indicate that the commercial inoculants tested were not satisfactory for the species studied. The nitrogenase activity level in the treatments that received no inoculation indicates the presence of a native nitrogen-fixing microflora in the soil. The selection of Rhizobium strains from within the native population is suggested as a promising method to obtain more adequate inoculants for the "cerrados" region.Experimento de campo num solo virgem de cerrado, em Brasília, DF, com as leguminosas: Centrosema pubescens, Styloanthes cupitata, Macroptilium atropurpureum, Galactia striata e Calopogonium mucunoides, com o fim de estudar a eficiência de inoculantes comerciais e de estirpes nativas de Rhizobium. O delineamento experimental foi o de blocos ao acaso, com quatro repetições, utilizando-se um fatorial completo de 3 x 6. Os tratamentos foram: a) testemunha, b) inoculação, e c) inoculação + 75 kg/ha de N. Não foi feita calagem do solo, mas foi incluído um tratamento adicional de 1 t/ha de calcário, em duas leguminosas. A inoculação nas leguminosas estudadas não produziu efeito benéfico, exceto na Centrosema pubescens, na qual elevou a nodulação, o N total e a produção de massa seca, em relação à testemunha. O tratamento com adubação nitrogenada obteve os melhores resultados em Centrosema pubescens, Macroptilium atropurpureum, Calopogonium macunoides e Galactia striata, indicando que a simbiose foi pouco efetiva nessas espécies. No baixo nível de fertilização usado no experimento, a simbiose com as estirpes nativas foi suficiente para suprir todo o nitrogénio necessário à Stylosanthes capitata e à S. bracteata. A adição de calcário aumentou a nodulação, o N total e a produção de forragem da Centrosema pubercens e do Stylosanthes capitata. Os resultados indicam que os inoculantes comerciais testados não foram eficientes para as espécies estudadas. O nível de atividade da nitrogenase nas parcelas que não receberam inoculação indicou a presença no solo de uma microflora autóctone com habilidade de fixar N2. A seleção de estirpes de Rhizobium dentro desta população nativa apresenta-se como um método promissor para a obtenção de inoculantes mais adequados para a região dos cerrados

Effect of levels and kinds of inoculant on soybean cultivated on a "cerrado" soil

Foi conduzido um experimento de campo em um solo de primeiro ano de cultivo com a soja (Glycine max (L.)Merrill), variedade IAC-2, visando a estudar o efeito de níveis de inoculantes e o comportamento de quatro inoculantes, sendo dois comerciais e dois preparados em laboratório. Um dos comerciais é recomendado para a cultivar IAC-2 e o outro é indicado para as demais cultivares de soja. Dos inoculantes fabricados em laboratório, um foi preparado com a estirpe 965 e o outro com a estirpe 29 W. Incluíram-se dois tratamentos com 400 kg/ha de N divididos em cinco aplicações em cobertura. Em um destes tratamentos, foram feitas aplicações suplementares de N via foliar (46 kg/ha de N divididos em cinco aplicações semanais a partir do início de formação dos grãos). O melhor tratamento de inoculação foi o do inoculante preparado em laboratório com a estirpe 29 W. Seguiu-se a este o tratamento com o inoculante recomendado para a variedade IAC-2. Os níveis de inoculante exerceram efeito significativo na nodulação e atividade da nitrogenase e um pequeno efeito no N total e produção de grãos. Os tratamentos com N mineral proporcionaram um rendimento de grãos e N total superiores aos obtidos nos tratamentos de inoculação. O N foliar apresentou um pequeno efeito no N percentual dos grãos. Depreende-se, dos resultados obtidos, que a variedade IAC-2 apresenta especificidade em relação às estirpes de Rhizobium, e que as estirpes testadas não apresentam grau de eficiência suficiente para permitir às plantas expressarem todo o seu potencial de produção.A field experiment was carried out with soybean (Glycine max (L.) Merrill) variety IAC-2, in order to study the effect of inoculant levels and four inoculants, two of them commercial and the others prepared in the laboratory. One of the commercial inoculants was recommended for the variety IAC-2, and the other one was a general non-specific inoculant for the remaining soybean varieties. The two laboratory-prepared inoculants were pure strains of 29 W and 965. Two treatments of 400 kg/ha of N divided into five side-dressing applications were included. One of those treatments received foliar applications of urea (46 kg/ha of N). The best inoculant treatment was the one prepared in the laboratory with the strain 29 W, followed by the commercial inoculant for the variety IAC-2. Levels of the latter inoculant had a significant effect on nodulation and nitrogenase activity but only a small effect on total N and grain yield. The foliar N application increased slightly the percentual N in the seeds, but had no effect on grain yield. Apparently, the variety IAC-2 tends to require specific Rhizobium strains and the strains and inoculants tested did not allow maximum expression of yield potential

Experiments on floating bed rotating drums using magnetic particle tracking

Magnetic particle tracking (MPT) was employed to study a rotating drum filled with cork particles, using both air and water as interstitial medium. This noninvasive monitoring technique allows for the tracking of both particle translation and rotation in dry granular and liquid–solid systems. Measurements on the dry and floating bed rotating drum were compared and detailed analysis of the bed shape and velocity profiles was performed. It was found that the change of particle–wall and particle–particle interaction caused by the presence of water significantly affects the bed behavior. The decreased friction leads to slipping of the particles with respect to the wall, rendering the circulation rate largely insensitive to increased drum speed. It was also found that the liquid–particle interaction is determining for the behavior of the flowing layer. The well-defined experiments and in-depth characterization performed in this study provide an excellent validation case for multiphase flow models.</p

Experiments and simulations on a cold-flow blast furnace hearth model

The blast furnace hearth plays an important role in the operational stability and lifetime of the reactor. The quasi-stagnant bed of coke particles termed the deadman undergoes complex interaction with the flowing hot metal, and remains largely ill-understood. In this work, a cold model blast furnace hearth is presented, and studied using both numerical and experimental techniques. Magnetic Particle Tracking (MPT) is used to investigate the individual particle behaviour within the cylindrical, opaque bed. At high liquid holdup, the particle bed was found to alternate between floating and sitting states, following the liquid level during the tapping and filling cycle. This bed motion was found to induce a migration of particles, thereby slowly renewing the deadman. The rate of horizontal migration increases with the vertical bed amplitude, and the renewal of particles is concentrated around the opening of the tap hole. No direct influence of the coke-free space on the tapping rate was found in these experiments. Instead, the disturbance of the packing in front of the tap hole was observed to lead to a higher tapping rate. Additionally, a coupled numerical framework is presented, in which Computational Fluid Dynamics (CFD), the Volume of Fluid (VOF) method and the Discrete Element Method (DEM) are combined. A simulation set-up is presented which closely replicates the experimental conditions. The position and movement of the floating bed are found to be well-predicted by the VOF/CFD-DEM model. Particle trajectories are presented, and migration of particles within the deadman is observed. Alongside the particle motion, the liquid flow pattern during draining of the vessel is visualised. It is concluded that a coke-free space underneath the deadman significantly impacts the shape of the liquid flow pattern, which affects the erosion processes within the blast furnace hearth.</p

Sobrevivência de estirpes de Rhizobium japonicum na superfície de sementes de soja inoculadas

The objective of this work was to study the possibility of recommending inoculation of soybean seeds before the planting time. For this purpose, the effect of inoculum formulation (water, sucrose solution (25%) and diesel oil as binders) and storage time (0, 1, 2, 4, 6 and 8 days) on the survival of Rhizobium on the surface of inoculated soybean seed was evaluated. Four experiments were carried out: two in the glasshouse and two in the field in Dark-Red and Yellow-Red Latossols at the Centro de Pesquisa Agropecuária dos Cerrados (CPAC) of EMBRAPA. In general, storage time did not affect Rhizobium survival. However, in the glasshouse experiments, nodulation in treatments with sucrose and water even with no storage period, were significantly greater than treatments with diesel oil. Although good nodulation was obtained with water alone, it was poorer than with sucrose. Results obtained under field conditions confirmed those from the glasshouse, indicating that if kept at an ambient temperature, inoculated soybean seeds can be stored for up to four days without affecting nodulation or grain production.Objetivou-se neste trabalho estudar a possibilidade de recomendar a inoculação da soja com Rhizobium antes do plantio. Para isto, avaliou-se o efeito de formas de inoculação (água, solução de sacarose 25% e óleo diesel como adesivos) e do período de armazenamento (0, 1, 2, 4, 6 e 8 dias) na sobrevivência do rizóbio na superfície da semente inoculada. Foram conduzidos 4 experimentos: dois em casa de vegetação e dois no campo, em Latossolos Vermelho-Escuro e Vermelho-Amarelo, no Centro de Pesquisa Agropecuária dos Cerrados, da EMBRAPA. De modo geral, não houve efeito do período de armazenagem na sobrevivência do rizóbio. Nos experimentos de casa de vegetação, a nodulação nos tratamentos com sacarose e água, mesmo no tempo zero de armazenamento, foi significativamente superior ao tratamento com óleo diesel. No tratamento com água, apesar de ter sido obtida uma boa nodulação, esta foi inferior à dos tratamentos com sacarose. Em condições de campo, foram confirmados os resultados de casa de vegetação, evidenciando a possibilidade de se estocar, à temperatura ambiente, sementes de soja inoculadas, isto é, revestidas com inoculante, por um período de até quatro dias, sem prejuízo para nodulação e produção de grãos

Programmable Ligand Detection System in Plants through a Synthetic Signal Transduction Pathway

There is an unmet need to monitor human and natural environments for substances that are intentionally or unintentionally introduced. A long-sought goal is to adapt plants to sense and respond to specific substances for use as environmental monitors. Computationally re-designed periplasmic binding proteins (PBPs) provide a means to design highly sensitive and specific ligand sensing capabilities in receptors. Input from these proteins can be linked to gene expression through histidine kinase (HK) mediated signaling. Components of HK signaling systems are evolutionarily conserved between bacteria and plants. We previously reported that in response to cytokinin-mediated HK activation in plants, the bacterial response regulator PhoB translocates to the nucleus and activates transcription. Also, we previously described a plant visual response system, the de-greening circuit, a threshold sensitive reporter system that produces a visual response which is remotely detectable and quantifiable.We describe assembly and function of a complete synthetic signal transduction pathway in plants that links input from computationally re-designed PBPs to a visual response. To sense extracellular ligands, we targeted the computational re-designed PBPs to the apoplast. PBPs bind the ligand and develop affinity for the extracellular domain of a chemotactic protein, Trg. We experimentally developed Trg fusions proteins, which bind the ligand-PBP complex, and activate intracellular PhoR, the HK cognate of PhoB. We then adapted Trg-PhoR fusions for function in plants showing that in the presence of an external ligand PhoB translocates to the nucleus and activates transcription. We linked this input to the de-greening circuit creating a detector plant.Our system is modular and PBPs can theoretically be designed to bind most small molecules. Hence our system, with improvements, may allow plants to serve as a simple and inexpensive means to monitor human surroundings for substances such as pollutants, explosives, or chemical agents

Expression Screening of Fusion Partners from an E. coli Genome for Soluble Expression of Recombinant Proteins in a Cell-Free Protein Synthesis System

While access to soluble recombinant proteins is essential for a number of proteome studies, preparation of purified functional proteins is often limited by the protein solubility. In this study, potent solubility-enhancing fusion partners were screened from the repertoire of endogenous E. coli proteins. Based on the presumed correlation between the intracellular abundance and folding efficiency of proteins, PCR-amplified ORFs of a series of highly abundant E. coli proteins were fused with aggregation-prone heterologous proteins and then directly expressed for quantitative estimation of the expression efficiency of soluble translation products. Through two-step screening procedures involving the expression of 552 fusion constructs targeted against a series of cytokine proteins, we were able to discover a number of endogenous E. coli proteins that dramatically enhanced the soluble expression of the target proteins. This strategy of cell-free expression screening can be extended to quantitative, global analysis of genomic resources for various purposes.National Research Foundation of KoreaKorea (South). Ministry of Education, Science and Technology (MEST) (grant 2011K000841)Korea (South). Ministry of Education, Science and Technology (MEST) (grant 2011-0027901

Perceptions of involvement in advance care planning and emotional functioning in patients with advanced cancer

Purpose: Advance Care Planning (ACP) is positively associated with the quality of care, but its impact on emotional functioning is ambiguous. This study investigated the association between perceptions of ACP involvement and emotional functioning in patients with advanced cancer. Methods: This study analyzed baseline data of 1,001 patients of the eQuiPe study, a prospective, longitudinal, multicenter, observational study on quality of care and quality of life in patients with advanced cancer in the Netherlands. Patients with metastatic solid cancer were asked to participate between November 2017 and January 2020. Patients’ perceptions of ACP involvement were measured by three self-administered statements. Emotional functioning was measured by the EORTC-QLQ-C30. A linear multivariable regression analysis was performed while taking gender, age, migrant background, education, marital status, and symptom burden into account. Results: The majority of patients (87%) reported that they were as much involved as they wanted to be in decisions about their future medical treatment and care. Most patients felt that their relatives (81%) and physicians (75%) were familiar with their preferences for future medical treatment and care. A positive association was found between patients’ perceptions of ACP involvement and their emotional functioning (b=0.162, p<0.001, 95%CI[0.095;0.229]) while controlling for relevant confounders. Conclusions: Perceptions of involvement in ACP are positively associated with emotional functioning in patients with advanced cancer. Future studies are needed to further investigate the effect of ACP on emotional functioning. Trial registration number: NTR6584 Date of registration: 30 June 2017 Implications for Cancer Survivors: Patients’ emotional functioning might improve from routine discussions regarding goals of future care. Therefore, integration of ACP into palliative might be promising

Identification of Candida glabrata genes involved in pH modulation and modification of the phagosomal environment in macrophages

notes: PMCID: PMC4006850types: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov'tCandida glabrata currently ranks as the second most frequent cause of invasive candidiasis. Our previous work has shown that C. glabrata is adapted to intracellular survival in macrophages and replicates within non-acidified late endosomal-stage phagosomes. In contrast, heat killed yeasts are found in acidified matured phagosomes. In the present study, we aimed at elucidating the processes leading to inhibition of phagosome acidification and maturation. We show that phagosomes containing viable C. glabrata cells do not fuse with pre-labeled lysosomes and possess low phagosomal hydrolase activity. Inhibition of acidification occurs independent of macrophage type (human/murine), differentiation (M1-/M2-type) or activation status (vitamin D3 stimulation). We observed no differential activation of macrophage MAPK or NFκB signaling cascades downstream of pattern recognition receptors after internalization of viable compared to heat killed yeasts, but Syk activation decayed faster in macrophages containing viable yeasts. Thus, delivery of viable yeasts to non-matured phagosomes is likely not triggered by initial recognition events via MAPK or NFκB signaling, but Syk activation may be involved. Although V-ATPase is abundant in C. glabrata phagosomes, the influence of this proton pump on intracellular survival is low since blocking V-ATPase activity with bafilomycin A1 has no influence on fungal viability. Active pH modulation is one possible fungal strategy to change phagosome pH. In fact, C. glabrata is able to alkalinize its extracellular environment, when growing on amino acids as the sole carbon source in vitro. By screening a C. glabrata mutant library we identified genes important for environmental alkalinization that were further tested for their impact on phagosome pH. We found that the lack of fungal mannosyltransferases resulted in severely reduced alkalinization in vitro and in the delivery of C. glabrata to acidified phagosomes. Therefore, protein mannosylation may play a key role in alterations of phagosomal properties caused by C. glabrata.Deutsche ForschungsgemeinschaftNational Institutes for HealthWellcome TrustBBSR