Mutagênese insercional da estirpe PAL5 de Gluconacetobacter diazotrophicus por transposição in vitro.

O presente trabalho mostra a utilidade da técnica de mutagênese insercional para a estirpe PAL5 de G. diazotrophicus, usando o transposon comercial EZ::Tn5 transposon insertion kit (Epicentre, número de catálogo EZI982K). Para avaliar a utilidade desta estratégia, a técnica foi aplicada ao gene GdluxI (GenBank YP 001603070), envolvido em monitoramento populacional ou quorum sensing, e que foi identificado no genoma da estirpe PAL5 (ROUWS, 2008). Esta técnica de mutagênese insercional não se restringe a este gene e pode ser aplicada a outros genes da estirpe PAL5 de G. diazotrophicus.bitstream/item/42765/1/COT116-09.pd

Drought tolerance conferred to sugarcane by association with Gluconacetobacter diazotrophicus: a transcriptomic view of hormone pathways

Sugarcane interacts with particular types of beneficial nitrogen-fixing bacteria that provide fixed-nitrogen and plant growth hormones to host plants, promoting an increase in plant biomass. Other benefits, as enhanced tolerance to abiotic stresses have been reported to some diazotrophs. Here we aim to study the effects of the association between the diazotroph Gluconacetobacter diazotrophicus PAL5 and sugarcane cv. SP70-1143 during water depletion by characterizing differential transcriptome profiles of sugarcane. RNA-seq libraries were generated from roots and shoots of sugarcane plants free of endophytes that were inoculated with G. diazotrophicus and subjected to water depletion for 3 days. A sugarcane reference transcriptome was constructed and used for the identification of differentially expressed transcripts. The differential profile of non-inoculated SP70-1143 suggests that it responds to water deficit stress by the activation of drought-responsive markers and hormone pathways, as ABA and Ethylene. qRT-PCR revealed that root samples had higher levels of G. diazotrophicus 3 days after water deficit, compared to roots of inoculated plants watered normally. With prolonged drought only inoculated plants survived, indicating that SP70-1143 plants colonized with G. diazotrophicus become more tolerant to drought stress than non-inoculated plants. Strengthening this hypothesis, several gene expression responses to drought were inactivated or regulated in an opposite manner, especially in roots, when plants were colonized by the bacteria. The data suggests that colonized roots would not be suffering from stress in the same way as non-inoculated plants. On the other hand, shoots specifically activate ABA-dependent signaling genes, which could act as key elements in the drought resistance conferred by G. diazotrophicus to SP70-1143. This work reports for the first time the involvement of G. diazotrophicus in the promotion of drought-tolerance to sugarcane cv. SP70-1143, and it describes the initial molecular events that may trigger the increased drought tolerance in the host plant

PDAM: automatizando o processo de planejamento de atividades agrícolas municipais.

As ações governamentais na agricultura vem sendo descentralizadas de forma crescente nos anos 90, fazendo com que estados e municípios assumam funções mais ativas no processo de desenvolvimento agrícola. Uma dificuldade que tem sido observada é a falta de informações sistematizadas para atividades de planejamento, execução e acompanhamento das ações programadas para a agricultura municipal. O PDAM - Sistema de Suporte à Elaboração do Plano Diretor Agrícola Municipal visa suprir essa necessidade.bitstream/item/76664/1/CNPTIA-COM.TEC.-13-01.pd

Orc1 Controls Centriole and Centrosome Copy Number in Human Cells

Centrosomes, each containing a pair of centrioles, organize microtubules in animal cells, particularly during mitosis. DNA and centrosomes are normally duplicated once before cell division to maintain optimal genome integrity. We report a new role for the Orc1 protein, a subunit of the origin recognition complex (ORC) that is a key component of the DNA replication licensing machinery, in controlling centriole and centrosome copy number in human cells, independent of its role in DNA replication. Cyclin A promotes Orc1 localization to centrosomes where Orc1 prevents Cyclin E-dependent reduplication of both centrioles and centrosomes in a single cell division cycle. The data suggest that Orc1 is a regulator of centriole and centrosome reduplication as well as the initiation of DNA replication

Genome-wide identification of microRNA and siRNA responsive to endophytic beneficial diazotrophic bacteria in maize

Background: Small RNA (sRNA) has been described as a regulator of gene expression. In order to understand the role of maize sRNA (Zea mays - hybrid UENF 506-8) during association with endophytic nitrogen-fixing bacteria, we analyzed the sRNA regulated by its association with two diazotrophic bacteria, Herbaspirillum seropedicae and Azospirillum brasilense. Results: Deep sequencing analysis was done with RNA extracted from plants inoculated with H. seropedicae, allowing the identification of miRNA and siRNA. A total of 25 conserved miRNA families and 15 novel miRNAs were identified. A dynamic regulation in response to inoculation was also observed. A hypothetical model involving copper-miRNA is proposed, emphasizing the fact that the up-regulation of miR397, miR398, miR408 and miR528, which is followed by inhibition of their targets, can facilitate association with diazotrophic bacteria. Similar expression patterns were observed in samples inoculated with A. brasilense. Moreover, novel miRNA and siRNA were classified in the Transposable Elements (TE) database, and an enrichment of siRNA aligned with TE was observed in the inoculated samples. In addition, an increase in 24-nt siRNA mapping to genes was observed, which was correlated with an increase in methylation of the coding regions and a subsequent reduction in transcription. Conclusion: Our results show that maize has RNA-based silencing mechanisms that can trigger specific responses when plants interact with beneficial endophytic diazotrophic bacteria. Our findings suggest important roles for sRNA regulation in maize, and probably in other plants, during association with diazotrophic bacteria, emphasizing the up-regulation of Cu-miRNA

Transformação de Gluconacetobacter diazotrophicus estirpe PAL 5 pela técnica de eletroporação.

Condições de cultivo das bactérias; Preparação de células eletrocomponentes de G. diazotrophicus estirpe PAL 5; Preparação do plasmídeo de teste pKT230; A eletroporação da estirpe PAL 5 de G. diazotrophicus; Verificação da identidade dos transformantes pelo método de PCR; Isolação do plasmídeo pKT230 dos transformantes de PAL 5.bitstream/CNPAB-2010/34093/1/cot084.pd

A concepção de um programa de computador genérico para gerenciamento de lavouras.

Este trabalho sintetiza o conhecimento acumulado nas fases de análise de requisitos, projeto e implementação de aplicações de computador para gerenciamento agrícola e apresenta a concepção de um programa genérico para o controle de lavouras. Esse programa permite configurar sistemas de produção para diversas culturas, de modo a apoiar o gerenciamento racional das lavouras, obedecendo a configuração escolhida e segundo o paradigma de sistemas reativos preconizado pelo projeto FMS (Farm Management Systems). O programa permite analisar o desempenho econômico da atividade agricola, através do acompanhamento sistemático dos custos dos insumos e serviços empregados e da renda de sua produção. Através de um processo prático e eficaz, essas informações são armazenadas em um banco de dados, de maneira organizada e consistente, permitindo sua utilização para melhorias sucessivas nos processos de planejamento e controle da produção agrícola

Proposta de uma cooperativa de banco de dados sobre recursos naturais na EMBRAPA.

RESUMO. Visando atender a demanda por informações geradas por seus centros de pesquisa, a EMBRAPA (Empresa Brasileira de Pesquisa Agropecuária) iniciou esforços para implantação de sua cooperativa de banco de dados. Uma cooperativa de banco de dados é formada por um conjunto de centros de dados interligados por um sistema de comunicação. Os centros de dados são elementos que permitem a coleta, armazenamento, procesamento, acesso e distribuição de dados. Alguns centros de pesquisa da EMBRAPA atuarão na cooperativa administrando os centros de dados. A consulta dos dados armazenados na cooperativa será realizada pelo usuário através de serviços hipermídia do WWW. Dados georeferenciados tais como mapas temáticos e levantamentos de solo poderão ser acessados pelos usuários da cooperativa.Agrosoft 1995

Differential sRNA Regulation in Leaves and Roots of Sugarcane under Water Depletion

Plants have developed multiple regulatory mechanisms to respond and adapt to stress. Drought stress is one of the major constraints to agricultural productivity worldwide and recent reports have highlighted the importance of plant sRNA in the response and adaptation to water availability. In order to increase our understanding of the roles of sRNA in response to water depletion, cultivars of sugarcane were submitted to treatment of ceasing drip irrigation for 24 hours. Deep sequencing analysis was carried out to identify the sRNA regulated in leaves and roots of sugarcane cultivars with different drought sensitivities. The pool of sRNA selected allowed the analysis of different sRNA classes (miRNA and siRNA). Twenty-eight and 36 families of conserved miRNA were identified in leaf and root libraries, respectively. Dynamic regulation of miRNA was observed and the expression profiles of eight miRNA were verified in leaf samples from three biological replicates by stem-loop qRT-PCR assay using the cultivars: SP90-1638 - sensitive cultivar- and; SP83-2847 and SP83-5073 - tolerant cultivars. Altered miRNA regulation was correlated with changes in mRNA levels of specific targets. Two leaf libraries from individual sugarcane cultivars with contrasting drought-tolerance properties were also analyzed. An enrichment of 22-nt sRNA species was observed in leaf libraries. 22-nt miRNA triggered siRNA production by cleavage of their targets in response to water depletion. A number of genes of the sRNA biogenesis pathway were down-regulated in tolerant genotypes and up-regulated in sensitive in response to water depletion treatment. Our analysis contributes to increase the knowledge on the roles of sRNA in sugarcane submitted to water depletion