Microbiologia
URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11840
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Resultados da Pesquisa
Item Expression of the nifH gene in diazotrophic bacteria in Eucalyptus urograndis plantations(Canadian Journal of Forest Research, 2016-02) Silva, Marliane de Cássia Soares da; Mendes, Igor Rodrigues; Paula, Thiago de Almeida; Dias, Roberto Sousa; Paula, Sérgio Oliveira de; Silva, Cynthia Canedo; Bazzolli, Denise Mara Soares; Kasuya, Maria Catarina MegumiA large proportion of eucalypt plantations in Brazil are located in areas with low soil fertility. The actions of microorganisms are of great importance for the cycling of nutrients, including nitrogen (N), that are essential for plant metabolism. Denaturing gradient gel electrophoresis (DGGE) was used to monitor and identify the total and active microorganisms involved in the N cycle in both the soil and root systems of a forest of Eucalyptus urograndis with sections that were fertilized with N or unfertilized. Quantitative real-time PCR was used to examine the expression of the nifH gene in N-fixing bacteria present in both the soil and root systems. According to the DGGE analysis, in the total and active populations of N-fixing bacteria, the presence and expression of the nifH gene were influenced by the winter and summer seasons and (or) N fertilization, respectively. DGGE band sequencing from total DNA samples showed that the most abundant group of diazotrophic bacteria belonged to Alphaproteobacteria in both the soil and root systems. Quantitative real-time PCR revealed that nifH expression was higher in the soil samples, especially in those that did not receive N fertilization. The differences in the composition of the total and active diazotrophic populations highlight the importance of evaluating the active populations, because they are effectively responsible for the biogeochemical transformation of N and also control its' availability to plants.