A cultura da mandioquinha-salsa e sua relação com os fungos micorrízicos.

A cultura da mandioquinha-salsa. Benefícios dos fungos micorrízicos arbusculares. Interações solo - micorrizas arbusculares. Possibilidade de relações entre a mandioquinha-salsa e os fungos micorrízicos arbusculares.bitstream/CNPAB-2010/32101/1/doc180.pd

Manual de soluções e reagentes da Embrapa Agrobiologia.

Solução de ácido acético a 10%.Solução de ácido acético a15%. Solução de ácido bórico a 1%. Soluções: Àcido sulfúrico a 5%. Água oxigenada a 3%. de azul de brotimol a 0,1%. de azul de brotimol a 0,5%. de azul de brotimol a 0,5% alcoolica p/v. Cloreto de sódio 2,5 %. Cloreto de sódio 10%. Cloreto de potássio. Dicromato de potássio. Edta de ferro. Fosfato de potássio Dibásico. Fosfato de potássio dibásico. Fosfato de potássio monobásico. fosfato de potássio monobásico. Hidroxido de potássio. Hidroxido de potássio. Hidroxido de de sódio. Molibdato de sódio dihidratado. Sulfato de magnésio. Sulfato de magnésio heptahidratado. Sulfato de potássio. Sulfato de manganês. Sulfato de ferro.bitstream/CNPAB-2010/27283/1/doc086.pd

Proposta de avaliação da atividade de enzimas antioxidantes em plantas de arroz após a aplicação de ácido húmico e bactérias promotoras de crescimento vegetal.

O presente trabalho visa avaliar as alterações no perfil de atividade de enzimas antioxidantes em plantas de arroz tratadas com bactérias promotoras do crescimento vegetal (BPCV) e ácidos húmicos (AH), e o papel da comunidade bacteriana endofítica frente aos mesmos tratamentos

Antioxidant pathways are up-regulated during biological nitrogen fixation to prevent ROS-induced nitrogenase inhibition in Gluconacetobacter diazotrophicus

Gluconacetobacter diazotrophicus, an endophyte isolated from sugarcane, is a strict aerobe that fixates N2. This process is catalyzed by nitrogenase and requires copious amounts of ATP. Nitrogenase activity is extremely sensitive to inhibition by oxygen and reactive oxygen species (ROS). However, the elevated oxidative metabolic rates required to sustain biological nitrogen fixation (BNF) may favor an increased production of ROS. Here, we explored this paradox and observed that ROS levels are, in fact, decreased in nitrogen-fixing cells due to the up-regulation of transcript levels of six ROS-detoxifying genes. A cluster analyses based on common expression patterns revealed the existence of a stable cluster with 99.8% similarity made up of the genes encoding the α-subunit of nitrogenase Mo–Fe protein (nifD), superoxide dismutase (sodA) and catalase type E (katE). Finally, nitrogenase activity was inhibited in a dose-dependent manner by paraquat, a redox cycler that increases cellular ROS levels. Our data revealed that ROS can strongly inhibit nitrogenase activity, and G. diazotrophicus alters its redox metabolism during BNF by increasing antioxidant transcript levels resulting in a lower ROS generation. We suggest that careful controlled ROS production during this critical phase is an adaptive mechanism to allow nitrogen fixation

Epicoccum nigrum P16, a Sugarcane Endophyte, Produces Antifungal Compounds and Induces Root Growth

Background: Sugarcane is one of the most important crops in Brazil, mainly because of its use in biofuel production. Recent studies have sought to determine the role of sugarcane endophytic microbial diversity in microorganism-plant interactions, and their biotechnological potential. Epicoccum nigrum is an important sugarcane endophytic fungus that has been associated with the biological control of phytopathogens, and the production of secondary metabolites. In spite of several studies carried out to define the better conditions to use E. nigrum in different crops, little is known about the establishment of an endophytic interaction, and its potential effects on plant physiology. Methodology/Principal Findings: We report an approach based on inoculation followed by re-isolation, molecular monitoring, microscopic analysis, plant growth responses to fungal colonization, and antimicrobial activity tests to study the basic aspects of the E. nigrum endophytic interaction with sugarcane, and the effects of colonization on plant physiology. The results indicate that E. nigrum was capable of increasing the root system biomass and producing compounds that inhibit the in vitro growth of sugarcane pathogens Fusarium verticillioides, Colletotrichum falcatum, Ceratocystis paradoxa, and Xanthomomas albilineans. In addition, E. nigrum preferentially colonizes the sugarcane surface and, occasionally, the endophytic environment. Conclusions/Significance: Our work demonstrates that E. nigrum has great potential for sugarcane crop application because it is capable of increasing the root system biomass and controlling pathogens. The study of the basic aspects of the interaction of E. nigrum with sugarcane demonstrated the facultative endophytism of E. nigrum and its preference for the phylloplane environment, which should be considered in future studies of biocontrol using this species. In addition, this work contributes to the knowledge of the interaction of this ubiquitous endophyte with the host plant, and also to a better use of microbial endophytes in agriculture.State of Sao Paulo Research Foundation (FAPESP)FAPESP (State of Sao Paulo Research Foundation) [02/14143-3, 10/08286-2]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq