RESUMO
Robust antifungal screening is technically challenging particularly for filamentous fungi. We present a method for undertaking antifungal screening assays that builds upon existing broth dilution protocols and incorporates time resolved image-based assessment of fungal growth. We show that the method performs with different fungi, particularly those for which spores can be used as inoculum, and with different compound classes, can accurately assess susceptibility or otherwise in only few hours and can even account for differences in inherent growth properties of strains.
Assuntos
Antifúngicos/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Fungos/efeitos dos fármacos , Ensaios de Triagem em Larga Escala/métodos , Processamento de Imagem Assistida por Computador/métodos , Testes de Sensibilidade MicrobianaRESUMO
Fusarium spp. are devastating fungal pathogens which cause significant losses in many cereal crops like wheat, maize, and barley. Genetic improvement of disease resistance requires an improved understanding of defense-associated processes operating in the host in response to an attack by Fusarium spp. Brachypodium distachyon is emerging as a model where host-cereal-infecting pathogen interactions can be studied conveniently. However, this requires developing an efficient infection assay that facilitates quick screening of germplasm (e.g., mutant lines). Here, we provide an efficient and reproducible Fusarium infection assay for Brachypodium. We believe this method will help further develop Brachypodium as a model for genetic improvement of disease resistance in cereals against Fusarium pathogens.
Assuntos
Brachypodium/genética , Brachypodium/microbiologia , Fusarium/fisiologia , Interações Hospedeiro-Patógeno , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Brachypodium/crescimento & desenvolvimento , Técnicas de Cultura de Células/métodos , Resistência à Doença , Fusarium/genética , Mutação , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/métodosRESUMO
Warmer temperatures associated with climate change are expected to have a direct impact on plant pathogens, challenging crops and altering plant disease profiles in the future. In this study, we have investigated the effect of increasing temperature on the pathogenic fitness of Fusarium pseudograminearum, an important necrotrophic plant pathogen associated with crown rot disease of wheat in Australia. Eleven wheat lines with different levels of crown rot resistance were artificially inoculated with F. pseudograminearum and maintained at four diurnal temperatures 15/15°C, 20/15°C, 25/15°C and 28/15°C in a controlled glasshouse. To quantify the success of F. pseudograminearum three fitness measures, these being disease severity, pathogen biomass in stem base and flag leaf node, and deoxynivalenol (DON) in stem base and flag leaf node of mature plants were used. F. pseudograminearum showed superior overall fitness at 15/15°C, and this was reduced with increasing temperature. Pathogen fitness was significantly influenced by the level of crown rot resistance of wheat lines, but the influence of line declined with increasing temperature. Lines that exhibited superior crown rot resistance in the field were generally associated with reduced overall pathogen fitness. However, the relative performance of the wheat lines was dependent on the measure of pathogen fitness, and lines that were associated with one reduced measure of pathogen fitness did not always reduce another. There was a strong correlation between DON in stem base tissue and disease severity, but length of browning was not a good predictor of Fusarium biomass in the stem base. We report that a combination of host resistance and rising temperature will reduce pathogen fitness under increasing temperature, but further studies combining the effect of rising CO2 are essential for more realistic assessments.
