Biology subjects

Sayago, P.

Publications and source records attributed to Sayago, P..

3 recordsLinked to original sources

bioRxiv2019

Development of an innovative in vitro method for mass production of Verticillium dahliae microsclerotia

The soil-borne fungal plant pathogen Verticillium dahliae can infect more than 300 plant species including important economic crops, causing great economic loses. V. dahliae can persist and survive more than 14 years in the soil by resistance structures, known as microsclerotia, which constitute the primary inoculum in the field. In vitro mass production of microsclerotia is essential for performing many pathological assays. Nevertheless to harvest the microsclerotia is not an easy task and several protocols have been described although none of them is completely satisfying for different reasons. here we present a new protocol that is reproducible, robust, simple and fast allows to overcome the difficulties for obtaining massive amounts of microsclerotia. In summary, we developed a new culture medium that we called Pluronic Potato Medium (PPM) because it is essentially potato dextrose media with the hydrogel, Pluronic F127 as a solidifying agent. The microsclerotia collected in form PPM were infectious in tomato plants were they were able to reproduce the disease and we recovered and quantitated V. dahliae in infected plants.

microbiology↗

bioRxiv2019

Bacillus subtilis ALBA01 can mitigate onion pink root symptoms caused by Setophoma terrestris

Soil-borne pathogen Setophoma terrestris is the causal agent of pink root of onion, one of the most challenging diseases in onion production. Conventional approaches for managing the disease like solarization, soil fumigation and crop rotation have not been proven effective enough. In this work, we evaluated the biocontrol capacity of Bacillus subtilis ALBA01 (BsA01) against S. terrestris, in a highly susceptible onion cultivar, both under greenhouse and field conditions. Disease incidence and severity were evaluated together with growth, photosynthesis among other physiological variables and yield parameters. When compared with plants infected with the pathogen, those plants co-inoculated with BsA01 showed significantly less damage and levels of biocontrol above 50%. With regard to physiological parameters, plants challenged with S terrestris and inoculated with BsA01 performed as well as the control non-infected plants revealing a growth promotion effect of BsA01 on onion plants.

microbiology↗

bioRxiv2018

Adaptation of Bacillus subtilis upon interaction with Setophoma terrestris results in loss of surfactin and plipastatin production

Environmental species of bacteria and fungi coexist and interact showing antagonistic and mutualistic behaviors, mediated by exchange of small diffusible metabolites, driving microbial adaptation to complex communal lifestyles1. Here we show that a wild Bacilus subtilis strain undergoes heritable phenotypic variation following interaction with the soil fungal pathogen Setophoma terrestris (ST) in co-culture. Metabolomics analysis revealed a differential profile in B. subtilis before (pre-ST) and after (post-ST) interacting with the fungus, which paradoxically involved the absence of lipopeptides surfactin and plipastatin and yet acquired antifungal activity in post-ST variants. Metabolic changes were also observed in the profile of volatile compounds, with 2-heptanone and 2-octanone being the most discriminating metabolites present at higher concentrations in post-ST during its interaction with the fungus. Most strikingly, both ketones showed strong antifungal activity against S. terrestris, which was lost with the addition of exogenous surfactin to the medium. Whole-genome analyses showed that mutations in the comA and comP genes of the ComQPXA quorum-sensing system, constituted the genetic bases of post-ST conversion, which allowed the concomitant production of ketones and elimination of surfactin. These findings suggest that mutations in ComQXPA stably rewired B. subtilis metabolism towards the depletion of surfactins and the production of antifungal compounds during its antagonistic interaction with S. terrestris.

microbiology↗