Project description:Composts are the products obtained after the aerobic degradation of different types of organic matter wastes and can be used as substrates or substrate/soil amendments. There are a small but increasing number of reports that suggest that foliar diseases may be reduced when using compost as growing medium compared to standard substrates. The purpose of this study was to unravel the gene expression alteration produced by the compost to gain knowledge about the mechanisms involved in the compost-induced systemic resistance. A compost from olive marc and olive tree leaves was able to induce resistance against Botrytis cinerea in Arabidopsis compared to the standard substrate perlite. Microarray analyses revealed that 178 genes were differently expressed with a fold change cut off of 1 from which 155 were upregulated and 23 were down regulated in compost-grown compared to perlite-grown plants. Functional enrichment study of up regulated genes revealed that 38 Gene Ontology terms were significantly enriched. Response to stress, biotic stimulus, other organism, bacterium, fungus, chemical and abiotic stimulus, SA and ABA stimulus, oxidative stress, water, temperature and cold were significantly enriched terms as well as immune and defense responses, systemic acquired resistance, secondary metabolic process and oxireductase activity. Interestingly, PR1 expression, which was equally enhanced by growing the plants in compost and by B. cinerea inoculation, was further boosted in compost-grown pathogen-inoculated plants. Compost triggered a plant response that shares similarities with both systemic acquired resistance and ABA dependent/independent abiotic stress responses.
Project description:Anthropogenic nutrient inputs alter soil biodiversity; however, it remains largely unknown whether changes in soil microeukaryotes (fungi and protists) are primarily driven by direct effects, such as modifications in soil properties, or by indirect effects, such as plant diversity loss. To disentangle these mechanisms, we investigated the long-term effects (11 years) of fertilization and manipulated plant diversity (1, 2, or 4 plant species) on soil microeukaryote communities in a temperate grassland experiment using long-amplicon rRNA sequencing. Our results indicate that fertilization generally had a stronger influence on microeukaryote communities than plant species richness. Fertilization altered the community composition of fungi and protists, increased OTU richness by 20.8% and 52.7%, respectively, and shifted community dominance from fungi to protists. Regarding plant diversity, we observed an effect exclusively on the protist community. Changes were primarily explained by increased plant biomass (driven by both fertilization and plant diversity) and by higher soil phosphorus and lower soil pH levels (driven exclusively by fertilization). Regarding life strategies, we observed synergistic treatment effects: fertilization primarily enhanced fungal saprophytes (only richness), fungal animal pathogens, and protist consumers, whereas plant diversity affected phototrophic protists (reduction) and protist animal pathogens (enhancement). Notably, fertilization and plant diversity decline together led to a cumulative increase in fungal plant pathogens. In conclusion, we highlight that fertilisation alone has a significant effect on soil microeukaryotes, while the additional decline in plant diversity affects different soil groups that are not directly affected by fertilisation. This synergistic pattern indicates that fertilization can influence the entire microeukaryote community through direct and indirect mechanisms, with a cumulative enhancement on certain groups, such as plant pathogens.
Project description:Oral administration of an extract of compost fermented with thermophiles to pigs reduces the incidence of stillbirth and promotes piglet growth. However, the mechanism by which compost extract modulates the physiological conditions of the animals remains largely unknown. Here, we investigate the effects of compost extract on the gene expression in the intestine of the rat as a mammalian model. Gene expression analyses of the intestine indicated that several immune-related genes were upregulated following compost exposure. Thus, thermophile-fermented compost can contain microbes and/or substances that activate the gut mucosal immune response in the rat.
2012-11-02 | GSE37732 | GEO
Project description:Study of phyllosphere fungal diversity