Nitrogen-fixing bacteria and arbuscular mycorrhizal fungi in Piptadenia gonoacantha ( Mart. ) Macbr

Abstract The family Leguminosae comprises approximately 20,000 species that mostly form symbioses with arbuscular mycorrhizal fungi (AMF) and nitrogen-fixing bacteria (NFB). This study is aimed at investigating and confirming the dependence on nodulation and biological nitrogen fixation in the specie Piptadenia gonoacantha (Mart.) Macbr., which belongs to the Piptadenia group. Two consecutive experiments were performed in a greenhouse. The experiments were fully randomized with six replicates and a factorial scheme. For the treatments, the two AMF species and three NFB strains were combined to nodulate P. gonoacantha in addition to the control treatments. The results indicate this species’ capacity for nodulation without the AMF; however, the AMF + NFB combinations yielded a considerable gain in P. gonoacantha shoot weight compared with the treatments that only included inoculating with bacteria or AMF. The results also confirm that the treatment effects among the AMF + NFB combinations produced different shoot dry weight/root dry weight ratios. We conclude that AMF is not necessary for nodulation and that this dependence improves species development because plant growth increases upon co-inoculation.

Draft genome sequence of Bradyrhizobium sp. strain BR 3262, an effective microsymbiont recommended for cowpea inoculation in Brazil

The strain BR 3262 was isolated from nodule of cowpea (Vigna unguiculata L. Walp) growing in soil of the Atlantic Forest area in Brazil and it is reported as an efficient nitrogen fixing bacterium associated to cowpea. Firstly, this strain was assigned as Bradyrhizobium elkanii, however, recently a more detailed genetic and molecular characterization has indicated it could be a Bradyrhizobium pachyrhizi species. We report here the draft genome sequence of B. pachyrhizi strain BR 3262, an elite bacterium used as inoculant for cowpea. The whole genome with 116 scaffolds, 8,965,178 bp and 63.8% of C+G content for BR 3262 was obtained using Illumina MiSeq sequencing technology. Annotation was added by the RAST prokaryotic genome annotation service and shown 8369 coding sequences, 52 RNAs genes, classified in 504 subsystems.

Draft genome sequence of Bradyrhizobium sp. strain BR 3267, an elite strain recommended for cowpea inoculation in Brazil

The strain BR 3267 is a nitrogen-fixing symbiotic bacteria isolated from soil of semi-arid area of Brazilian Northeast using cowpea as the trap plant. This strain is used as commercial inoculant for cowpea and presents high efficient in nitrogen fixation as consequence of its adaptation potential to semi-arid conditions. We report here the draft genome sequence of Bradyrhizobium sp. strain BR 3267, an elite bacterium used as inoculant for cowpea. Whole genome sequencing of BR 3267 using Illumina MiSeq sequencing technology has 55 scaffolds with a total genome size of 7,904,309 bp and C+G 63%. Annotation was added by the RAST prokaryotic genome annotation service and has shown 7314 coding sequences and 52 RNA genes.

Symbiotic potential and survival of native rhizobia kept on different carriers

Native rhizobia are ideal for use as commercial legume inoculants. The characteristics of the carrier used to store the inoculants are important for the survival and symbiotic potential of the rhizobia. The objective of this study was to investigate the effects of peat (PEAT), perlite sugarcane bagasse (PSB), carboxymethyl cellulose plus starch (CMCS), and yeast extract mannitol supplemented with mannitol (YEMM) on the survival, nodulation potential and N₂ fixation capacity of the native strains Sinorhizobium mexicanum ITTG R7^T and Rhizobium calliandrae LBP2-1^T and of the reference strain Rhizobium etli CFN42^T. A factorial design (4 × 3) with four repetitions was used to determine the symbiotic potential of the rhizobial strains. The survival of the strains was higher for PEAT (46% for strain LBP2-1^T, 167% for strain CFN42^T and 219% for strain ITTG R7^T) than for the other carriers after 240 days, except for CFN42^T kept on CMCS (225%). All the strains kept on the different carriers effectively nodulated common bean, with the lowest number of nodules found (5 nodules) when CFN42^T was kept on CMCS and with the highest number of nodules found (28 nodules) when ITTG R7^T was kept on PSB. The nitrogenase activity was the highest for ITTG R7^T kept on PEAT (4911 μmol C₂H₄ per fresh weight nodule h⁻¹); however, no activity was found when the strains were kept on YEMM. Thus, the survival and symbiotic potential of the rhizobia depended on the carrier used to store them.

Imunidade humoral de Rhodnius prolixus: impacto sobre a microbiota e desenvolvimento de Trypanosoma cruzi e Trypanosoma rangeli / Humoral immunity of Rhodnius prolixus: impact on microbiota and Trypanosoma cruzi and Trypanosoma rangeli development

Rhodnius prolixus é um dos principais insetos vetores de Trypanosomacruzi e de Trypanosoma rangeli na América Latina. A produção de peptídeosantimicrobianos (AMPs) no trato digestivo ou corpo gorduroso do inseto é vitalpara evitar a proliferação de microrganismos patogênicos além de manter ahomeostasia da microbiota nativa. O presente trabalho focou na modulação daimunidade humoral do intestino médio de R. prolixus desafiados oralmente coma bactéria Gram-positiva Staphylococcus aureus e Gram-negativa Escherichiacoli, além de seus tripanosomatídeos naturais T. rangeli e T. cruzi, considerandoa influência do desenvolvimento dos parasitas sobre a microbiota intestinal. Emcondições normais, a região anterior do intestino médio houve maior abundânciade transcritos de genes de lisozimas (lis) e defensinas (def), enquanto naposterior, do gene da prolixicina (prol). Insetos alimentados com bactérias Gramnegativasapresentaram maior quantidade de transcritos de defC e prol,enquanto a ingestão de bactérias Gram-positivas induziu a expressão de defA edefB no intestino médio. A infecção por T. rangeli cepa Macias diminuiu aatividade fenoloxidásica, os níveis de expressão de lisozimas e prolixicina, aomesmo tempo em que induziu aumento de atividade antibacteriana e dos níveisde defensina C no tubo digestivo do inseto, também modificando a composiçãode bactérias nativas...

Rhodnius prolixus is a major vector of Trypanosoma rangeli andTrypanosoma cruzi, in Latin America. The production of antimicrobial peptides(AMPs) in the midgut of the insect is vital to control possible infection, and tomaintain the microbiota already present in the digestive tract. This work focuseson the modulation of the humoral immune responses of the midgut of R. prolixusorally challenged with Gram positive and Gram negative bacteria as well with T.rangeli Macias strain, T. cruzi Dm 28c and Y strain, considering the influence ofthe parasites on the intestinal microbiota. Our results showed that the anteriormidgut contents of control insects contain a higher inducible antibacterial activityand AMPs transcript abundance than those of the posterior midgut. Insects orallyfed with Gram-negative bacteria presented higher amount of defC and proltranscripts, while the ingestion of Gram-positive induced defA and defBexpression in the midgut. T. rangeli Macias strain successfully colonized R.prolixus midgut through a decreasing in PO activities, prolixicin and lysozymelevels, while at the same time induced an increase in antibacterial activity andupregulated defC levels in the insect anterior midgut. T. rangeli infection alsodiminishes the amount of cultivable gut bacteria as well modified the compositionof indigenous microorganisms. Furthermore, different T. cruzi strains presentdistinct profiles of immune system and microbiota modulation in R. prolixusmidgut, where T. cruzi Dm 28c was able to induce an increase in defensin Cgenes and a depression in prolixicin genes, while drastically reduce the cultivablebacteria population. In the other hand T. cruzi Y was not competent to induceAMPs expression in the gut or considerably reduce the microbiota in the anteriormidgut...

Retalho Duoescapular: uma nova opção na cirurgia reparadora do ombro / Duoscapular flap: a new option in shoulder reconstructive surgery

INTRODUÇÃO: O Dermatofibrossarcoma do Ombro é patologia incomum e seu tratamento demanda extensas ressecções. O sistema escapular é fonte de retalhos bastante utilizados nesta região. MÉTODO: Realizado estudo longitudinal, prospectivo, através da condução de um caso de Dermatofibrossarcoma Protuberans em ombro direito, submetido a ressecção e reconstrução local com Retalho Duoescapular, obtido através da associação dos retalhos escapular e paraescapular. RESULTADOS: Paciente evoluiu sem intercorrências no pós-operatório, não sendo observadas complicações sistêmicas e locais, e limitações funcionais. CONCLUSÃO: O Retalho Duoescapular é nova e relevante opção para reconstrução de feridas extensas, com exposição de estruturas nobres no ombro. Permite fechamento primário da área doadora, sem acrescentar morbidade ao procedimento.

INTRODUCTION: Shoulder cutaneous fibrosarcoma is an unusual pathology that requires extensive resections. The scapula is a source of flaps widely used in this region. METHOD: A longitudinal and prospective study was carried out in a patient with protuberans cutaneous fibrosarcoma on the right shoulder who underwent resection followed by local reconstruction with a Duoscapular Flap (a combination of scapular and parascapular flaps). RESULTS: The patient had no postoperative complications, as systemic and local complications as well as functional limitations were not observed. CONCLUSION: Duoscapular Flap placement is a novel procedure and a relevant choice for the reconstruction of extensive wounds exposing noble structures in the shoulder. It allows the primary closure of the donor area without increasing the morbidity of the procedure.

Phenotypic and Genotypic Characteristics of Rhizobia Isolated from Meknes-tafilalet Soils and Study of Their Ability to Nodulate Bituminaria bituminosa.

Aims: The objectives were to isolate and characterize phenotypically and genotypically the rhizobial strains from the soils belonging to the Meknes-Tafilalet region in order to select strains that are able to nodulate Bituminaria bituminosa. Study Design: An experimental study. Place and Duration of Study: Department of biology (Soil & Environment Microbiology Unit) Faculty of Sciences, Moulay Ismail University and Technical Support Unit for Scientific Research, CNRST in Rabat; between January and August 2010. Methodology: Samples from 23 different sites belonging to the Meknes-Tafilalet region were collected in order to select rhizobial strains that are able to nodulate Bituminaria bituminosa. The morphological, cultural and phenotypic parameters of isolated strains were studied. The phenotypic characteristics include colony morphology, growth speed, tolerances to temperature, salt and pH. To assess the genotypic diversity among the isolates, molecular characteristics based on 16S rDNA gene sequencing were performed. Results: The majority of the isolated strains showed fast-growing capacity (75%). Most strains tolerate neutral to alkaline pH, however some strains (18%) showed weak growth capacity at pH 4. All isolates were tolerant to high salt stress ([NaCl] = 3%). The genotypic characterization based on16S rDNA gene sequencing of the twelve strains showed a high diversity between the isolates. Conclusion: Taken together, our results highlight the important biodiversity of the isolated rhizobial strains and open opportunities for the development of new bio-fertilizer.

Resposta de cultivares de feijoeiro-comum à inoculação das sementes com duas estirpes de rizóbio / Common bean cultivars response to seed inoculation with two rhizobium strains

Fixação simbiótica de nitrogênio pode ser uma alternativa para reduzir, ou mesmo substituir, a adubação nitrogenada do feijoeiro-comum, cultura na qual ainda há descrédito quanto aos benefícios da inoculação e que se caracteriza por aplicações de altas doses de N mineral. Com o objetivo de verificar a resposta de cultivares de feijoeiro-comum à inoculação das sementes com duas estirpes de rizóbio, foram conduzidos dois experimentos de campo na safra de inverno 2010 (Patos de Minas e Uberaba, MG). Utilizou-se o delineamento em blocos casualizados, com três repetições e esquema fatorial 8 x 3, envolvendo oito cultivares (União, Madrepérola, Supremo, Ouro Negro, Ouro Vermelho e Majestoso) e três tipos de inoculação (sementes não inoculadas e estirpes CIAT 899T e UFLA 04-173). Na floração, avaliaram-se o número e massa seca de nódulos, massa seca de parte aérea e teor e acúmulo de nitrogênio (N) na parte aérea e, na colheita, o rendimento de grãos com seus componentes primários, teor e acúmulo de N nos grãos. Constatou-se que as populações nativas promovem nodulação equivalente à das estirpes inoculadas. As estirpes CIAT 899T e UFLA 04-173 favorecem o crescimento vegetativo do feijoeiro. A estirpe CIAT 899T proporciona maior número de vagens e maior massa de grãos que a estirpe UFLA 04-173, e em Uberaba também proporciona maior rendimento de grãos. Quando a inoculação é realizada com a estirpe UFLA 04-173, as cultivares diferem quanto ao teor foliar de N. As cultivares Madrepérola, Ouro Negro e Ouro Vermelho apresentam mais nódulos e maior massa seca de parte aérea, além de maior produtividade em Patos de Minas. Ouro Negro situa-se entre as mais produtivas em Uberaba. Em Uberaba há maior acúmulo de matéria seca de nódulos e de parte aérea, mas o ambiente Patos de Minas resulta em maiores valores do rendimento de grãos e componentes.

The symbiotic nitrogen fixation can be an alternative to reduce, or even replace, the nitrogen (N) fertilization of the common bean crop, characterized by application of high doses of this nutrient. This work aimed to verify the response of common bean cultivars to the seed inoculation with two Rhizobium strains, conducting two field experiments in the winter-spring crop of 2010, at Patos de Minas and Uberaba, Minas Gerais State, Brazil. The experiment had a randomized block design, with three replications and a 8 x 3 factorial squemme, involving eight cultivars and three levels of inoculation. At flowering, it was evaluated the number of nodules, nodules dry mass, shoots dry weight, N content and accumulation in shoots and, at harvest, the grain yield and its primary components (100 grains weight, number of pods per plant, number of grains per pod) and the N content and accumulation in the grains. The Madrepérola, Ouro Negro and Ouro Vermelho cultivars present the highest number of nodules and higher dry mass; in Patos de Minas, the same cultivars show higher productivity, but in Uberaba, only Ouro Negro cultivar is among the most productive. In Uberaba there is the greater nodules dry weight and higher shoots dry matter, but the most favorable conditions in Patos de Minas results in higher values for grain yield and its components. In Uberaba, the CIAT 899T strain overcomes the UFLA 04-173 strain in relation to grain yield. In both environments, the CIAT 899T strain also shows superiority in number of pods per plant and weight of one hundred grains.

Desempenho de cultivares transgênicas de soja em sucessão a culturas de inverno em semeadura direta / Performance of transgenic soybean cultivars in succession to winter cover crops under no tillage system

Objetivou-se com esse trabalho avaliar o desempenho de cultivares de soja transgênica em sucessão a culturas de inverno na implantação do sistema de semeadura direta. O delineamento experimental utilizado foi o de blocos casualizados, em esquema de parcelas subdivididas, com quatro repetições. As parcelas foram representadas por cinco espécies cultivadas no inverno, aveia branca, nabo forrageiro, cevada, trigo e ervilha forrageira e área de pousio. As subparcelas foram constituídas por seis cultivares de soja (BRS 243 RR, BRS 244 RR, BRS 245 RR, BRS 247 RR, BRS 255 RR e BRS 256 RR). Para as características agronômicas e os componentes de produção da cultura da soja indicou que a interação culturas de inverno x cultivares de soja foi significativa para a população final de plantas, número de nódulos por planta, massa de matéria seca de nódulos por planta, número de vagens por planta, número de grãos por vagem e produtividade de grãos. O tratamento de pousio proporcionou os menores valores de nodulação da cultura da soja. Para produtividade de grãos, houve diferenças entre as culturas de inverno antecessoras para o cultivar BRS 243 RR, sendo que, a aveia proporcionou maiores valores.

The objective of this research was to evaluate crop yield and some characteristics and yield components of transgenic soybean cultivars sown after different winter cover crops in the first year under no tillage system. The experimental design was the completely randomized block with split plots and four replications. The main plots consisted of five winter cover crops, white oat (Avena sativa L.), forage turnip (Raphanus sativus L.), barley (Hordeum vulgare L.), wheat (Triticum aestivum L.) and ground pea (Pisum sativum L.) and an area under fallow (spontaneous vegetation). The subplots consisted of six soybean cultivars (BRS 243 RR, BRS 245 RR, BRS 247 RR, BRS 255 RR, BRS 256 RR and BRS 244 RR). Variance analysis for agronomic characteristics showed that soybean yield components were influenced by the interaction between winter crop and soybean cultivar. Thus, final population, number of nodes and pods per plant, nodes dry matter per plant, number of grains per pod and grain yield were affected significantly. When soybean nodulation was evaluated, the treatment with the area under fallow showed lower values. There was difference among winter crops for BRS 243 RR grain yield, white oat showed the highest values.

Nodulação e atividade da nitrato redutase em função da aplicação de molibdênio em soja / Nodulation and nitrate reductase activity affected by molybdenum application in soybean

Entre os nutrientes essenciais para o processo de fixação biológica do nitrogênio pela soja, o molibdênio destaca-se por ser cofator da enzima nitrato redutase, afetando a sua atividade e, consequentemente, o processo de nodulação. O trabalho objetivou avaliar os efeitos da aplicação de molibdênio na nodulação de soja e na atividade da enzima nitrato redutase. O experimento foi conduzido em casa de vegetação, semeando-se a soja em vasos de 12 L e conduzindo-se duas plantas por vaso. Os tratamentos constaram de duas vias de aplicação (via semente e via foliar) e duas doses de molibdênio (12 e 24 g ha-1 via semente e 0, 30 e 60 g ha-1 via foliar) na forma de molibdato de amônio, mais a testemunha. Avaliou-se o número e massa seca de nódulos, teor de nitrogênio nas folhas e atividade da enzima nitrato redutase, em dois horários de coleta das folhas de soja (às 10 e 22 horas). Concluiu-se que a nodulação em soja é afetada pela dose e via de aplicação de molibdênio, sendo que maior número e massa de nódulos são obtidos com a aplicação de 24 g ha-1 do nutriente via semente. A atividade da enzima nitrato redutase é afetada pela adubação com molibdênio, independente da via de aplicação e do horário de coleta das folhas para avaliação, sendo crescente com a elevação das doses de Mo.

Among the nutrients that are essential for the biological nitrogen fixation by soybean plants, molybdenum stands out for being a cofactor of the nitrate reductase, affecting enzymatic activity and, consequently, the nodulation process. The research had as objective to evaluate the effects of molybdenum application on soybean nodulation and nitrate reductase activity. The experiment was conduced in greenhouse, sowing soybean in 12 L pots, with two plants per plot. The treatments consisted of two application via (with the seeds and leaf dressing) and two Nodulação e atividade molybdenum doses (12 and 24 g ha-1 with the seeds; 30 and 60 g ha-1 leaf dressing) in ammonium molybdate form, plus the control. The number and dry mass of nodules and nitrogen content in soybean leaves were evaluated. Samples of leaves for the evaluation of nitrate reductase activity were taken at 10 a.m. and 10 p.m. It was concluded that soybean nodulation is affected by Mo dose and application via, resulting in higher number and weight of nodules when it is applied with the seeds. The enzymatic activity of the nitrate reductase is influenced by Mo fertilization and it is higher for leaf dressing with the double of the recommended dose