title: Isolation and characterization of active promoters from Gluconacetobacter diazotrophicus strain PAL5 using a promoter-trapping plasmid.
abstract: Gluconacetobacter diazotrophicus is a nitrogen-fixing, endophytic bacterium that has the potential to promote plant growth and increase yield. Genetically modified strains might get more benefits to host plants, including through expression of useful proteins, such as Cry toxins from B. thuringiensis, or enzymes involved in phytohormone production, proteins with antagonistic activity for phytopathogens, or that improve nutrient utilization by the plant. For that, expression systems for G. diazotrophicus are needed, which requires active promoters fused to foreign (or innate) genes. This article describes the construction of a G. diazotrophicus PAL5 promoter library using a promoter-less lacZ-bearing vector, and the identification of six active promoters through β-galactosidase activity assays, sequencing and localization in the bacterial genome. The characterized promoters, which are located on distinct regions of the bacterial genome and encoding either sense or antisense transcripts, present variable expression strengths and might be used in the future for expressing useful proteins.
authors.affiliation: Embrapa Agrobiologia, Rodovia BR 465 km 7, Seropédica, RJ, Brazil. stefan.schwab@embrapa.br.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schwab
authors.affiliation: Embrapa Agrobiologia, Rodovia BR 465 km 7, Seropédica, RJ, Brazil.|Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ, Brazil.
authors.forename: Cristiane Alves
authors.initials: CA
authors.lastname: Pessoa
authors.affiliation: Embrapa Agrobiologia, Rodovia BR 465 km 7, Seropédica, RJ, Brazil.|Instituto de Tecnologia, Universidade Federal Rural do Rio de Janeiro, Rodovia BR 465 km 7, Seropédica, RJ, Brazil.
authors.forename: Amanda Aparecida
authors.initials: AA
authors.lastname: de Lima Bergami
authors.affiliation: Embrapa Agrobiologia, Rodovia BR 465 km 7, Seropédica, RJ, Brazil.|Instituto de Agronomia, Universidade Federal Rural do Rio de Janeiro, Rodovia BR 465 km 7, Seropédica, RJ, Brazil.
authors.forename: Nathália Lima
authors.initials: NL
authors.lastname: de Azevedo Figueiredo
authors.affiliation: Embrapa Agrobiologia, Rodovia BR 465 km 7, Seropédica, RJ, Brazil.
authors.forename: Kátia Regina
authors.initials: KR
authors.lastname: Dos Santos Teixeira
authors.affiliation: Embrapa Agrobiologia, Rodovia BR 465 km 7, Seropédica, RJ, Brazil.
authors.forename: José Ivo
authors.initials: JI
authors.lastname: Baldani
mesh_terms: D015723:Gene Library; D005821:Genetic Techniques; D016680:Genome, Bacterial / Q000235:genetics*; D041821:Gluconacetobacter / Q000235:genetics*; D010937:Plant Growth Regulators / Q000378:metabolism; D010944:Plants / Q000382:microbiology; D010957:Plasmids / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D010937:Plant Growth Regulators; D001616:beta-Galactosidase
keywords: Endophytic diazotroph; Plant growth promotion; Promoter trap; Protein expression system