RESUMO
Despite their monophyletic origin, mitochondrial (mt) genomes of plants and animals have developed contrasted evolutionary paths over time. Animal mt genomes are generally small, compact, and exhibit high mutation rates, whereas plant mt genomes exhibit low mutation rates, little compactness, larger sizes, and highly rearranged structures. We present the (nearly) whole sequences of five new mt genomes in the Beta genus: four from Beta vulgaris and one from B. macrocarpa, a sister species belonging to the same Beta section. We pooled our results with two previously sequenced genomes of B. vulgaris and studied genome diversity at the species level with an emphasis on cytoplasmic male-sterilizing (CMS) genomes. We showed that, contrary to what was previously assumed, all three CMS genomes belong to a single sterile lineage. In addition, the CMSs seem to have undergone an acceleration of the rates of substitution and rearrangement. This study suggests that male sterility emergence might have been favored by faster rates of evolution, unless CMS itself caused faster evolution.
Assuntos
Beta vulgaris/genética , DNA Mitocondrial/genética , Variação Genética , Genoma Mitocondrial/genética , Sequência de Bases , Beta vulgaris/classificação , Mapeamento Cromossômico , Cromossomos de Plantas/genética , DNA de Cloroplastos/química , DNA de Cloroplastos/genética , DNA Mitocondrial/química , DNA de Plantas/química , DNA de Plantas/genética , Evolução Molecular , Genes Mitocondriais/genética , Genoma de Planta/genética , Genômica/métodos , Dados de Sequência Molecular , Mutação , Filogenia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Especificidade da Espécie , SinteniaRESUMO
Norrström catchment, west of Stockholm, covers most of the Mälaren valley. Provision of drinking water from Lake Mälaren is an absolute precondition for continued growth in the region. Stockholm County's population is expected to increase by 600,000 people before 2030. Current climate change predictions anticipate significant temperature and precipitation increases. We implement the PolFlow model embedded in PCRaster for quantifying water and substances fluxes on the catchment scale over a 30-year time horizon. We formulate scenarios for changes in water quality and quantity due to climate change and population development. Results indicate a mild impact from climate change on surface flow rates but substantial effects on sub-surface residence times. Population development slightly affects nutrients loads. Using source apportionment and sensitivity analysis, we identify a number of critical parameters/processes to be further studied, in order for future results to be more reliable and usable in a water resources management context.
