Скачать или смотреть Roeland Berendsen. The Microbiome to the Rescue

Microbial communities surrounding plant roots play a decisive role in determining plant health. This is evidenced by the existence of disease suppressive soils. Disease suppressiveness is based on microbial activity and related to the presence of specific bacteria that antagonize the pathogen. The build-up of disease suppressive bacteria in the soil to an effective level requires successive years of monoculturing the same plant species and a severe disease outbreak. These observations have led to the hypothesis that upon attack plants recruit specific microbes that aid them in their defense. When and how this recruitment takes place is largely unknown. In this study, we investigated changes in the rhizosphere microbiome of the plant model Arabidopis thaliana upon attack by different above-ground pathogens. We found that three of the detected OTU’s were significantly more abundant in the rhizosphere of plants infected by the biotrophic pathogen Hyaloperonospora arabidopsidis than in the rhizosphere of control plants. In general, plants defend themselves against biotrophic pathogens using defense signaling pathways dependent on the plant hormone salycilic acid (SA), whereas defense against necrotophic pathogens is dependent on jasmonic acid. Our results indicate that SA-dependent defense signaling pathways are involved in recruitment of bacteria upon attack.