RESUMEN
Plant microbiomes are pivotal for healthy plant physiological development. Microbes live in complex co-association with plant hosts, and interactions within these microbial communities vary with plant genotype, plant compartment, phenological stage, and soil properties, among others. Plant microbiomes also harbor a substantial and diverse pool of mobile genes encoded on plasmids. Several plasmid functions attributed to plant-associated bacteria are relatively poorly understood. Additionally, the role of plasmids in disseminating genetic traits within plant compartments is not well known. Here, we present the current knowledge on the occurrence, diversity, function, and transfer of plasmids in plant microbiomes, emphasizing the factors that could modulate gene transfer in-planta. We also describe the role of the plant microbiome as a plasmid reservoir and the dissemination of its genetic material. We include a brief discussion on the current methodological limitations in studying plasmid transfer within plant microbiomes. This information could be useful to elucidate the dynamics of the bacterial gene pools, the adaptations different organisms have made, and variations in bacterial populations that might have never been described before, particularly in complex microbial communities associated with plants in natural and anthropogenic impacted environments.
Asunto(s)
Microbiota , Plásmidos/genética , Microbiota/genética , Bacterias/genética , Genes Bacterianos , Genotipo , Plantas/genéticaRESUMEN
When novel sources of ecological opportunity are available, physiological innovations can trigger adaptive radiations. This could be the case of yeasts (Saccharomycotina), in which an evolutionary novelty is represented by the capacity to exploit simple sugars from fruits (fermentation). During adaptive radiations, diversification and morphological evolution are predicted to slow-down after early bursts of diversification. Here, we performed the first comparative phylogenetic analysis in yeasts, testing the "early burst" prediction on species diversification and also on traits of putative ecological relevance (cell-size and fermentation versatility). We found that speciation rates are constant during the time-range we considered (ca., 150 millions of years). Phylogenetic signal of both traits was significant (but lower for cell-size), suggesting that lineages resemble each other in trait-values. Disparity analysis suggested accelerated evolution (diversification in trait values above Brownian Motion expectations) in cell-size. We also found a significant phylogenetic regression between cell-size and fermentation versatility (R (2) = 0.10), which suggests correlated evolution between both traits. Overall, our results do not support the early burst prediction both in species and traits, but suggest a number of interesting evolutionary patterns, that warrant further exploration. For instance, we show that the Whole Genomic Duplication that affected a whole clade of yeasts, does not seems to have a statistically detectable phenotypic effect at our level of analysis. In this regard, further studies of fermentation under common-garden conditions combined with comparative analyses are warranted.
RESUMEN
Introducción: La verificación y seguimiento de la presencia de microrganismos indicadores de la calidaddel agua es imprescindible debido al riesgo que representan para la población que la utiliza para consumo, recreación o deporte. Los reservorios acuíferos de Corrales de San Luis Beltrán, Atlántico, Colombia, son fuente de sustento de las comunidades campesinas aledañas, animales y plantas de la reserva; sin embargo, su calidad microbiológica no ha sido estudiada. Objetivo: Evaluar la calidad sanitaria del agua de reservorios acuíferos de Corrales de San Luis Beltrán. Materiales y métodos: Se realizaron muestreos de aguas superficiales y sedimento de reservorios acuíferos de Corrales de San Luis Beltrán, y se midieron in situ algunos parámetros fisicoquímicos (temperatura, pH, y oxígeno disuelto), y la calidad microbiológica (coliformes totales, coliformes fecales y bacterias reductoras de sulfato). Resultados: Se presentaron concentraciones bajas de oxígeno disuelto (2,71 mg/L), temperatura promedio de 26 °C y pH ligeramente básico (8,1). Los coliformes totales oscilaron entre 1,0x104 y 1,3x107 UFC/100 mL y los fecales entre 0 y 1,3x105 UFC/100 mL. Se encontró una correlación negativa entre el pH y los coliformes totales, y entre el oxígeno disuelto y los coliformes fecales; y una correlación positiva entre los coliformes fecales y la temperatura. Los recuentos de bacterias reductoras de sulfato fueron superiores a 103 UFC/100 g...
Introduction: The verification and monitoring of indicator microorganisms of water quality is essential.A low water quality may represent a risk for human health, because human populations frequently use it for consumption, recreation, or sport. Water reservoirs situated in Corrales de San Luis Beltran, Atlantico, Colombia, are source of sustenance to local peasant communities, animals, and plants around the village. However, the microbiological quality has not been established. Objective: To assess the sanitary water quality from Corrales de San Luis Beltran. Materials and methods: Surface water and sediment were sampled and some physicochemical parameters (temperature, pH, and dissolved oxygen), and the microbiological quality (total coliforms, fecal coliforms, and sulfate-reducing bacteria) were measured in situ. Results: The analysis showed low dissolved oxygen levels (2,71 mg/L), an average temperature of 26 °C and a slightly basic pH (8,1). Total coliform counts ranged from 1,0x104 and 1,3 x 107 CFU/100 mL and fecal coliform between 0 and 1,3 x 105 CFU/100 g. A negative correlation occurred between pH and total coliform as well as between dissolved oxygen and fecal coliforms. In addition, a positive correlation occurred between fecal coliform and temperature. The number of sulfate-reducing bacteria was more than 103 CFU/100 mL...