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:Purpose: The recent publication of the fungal mutualist R. irregularis genome facilitated transcriptomic studies. We here adress the gene regulation of R. irregularis in response to root exudates from rice wild-type and osnope1 (no perception candidate - mutant unable to host arbuscular mycorrhizal fungi) Methods: Spores of R. irregularis were treated with root exudates and collected at 1 hour, 24 hours and 7 days after addition. To monitor fungal gene regulation, control conditions were also prepared at T0, 1h, 24h and 7d. mRNA were sequenced by HiSeq Illumina. Reads were mapped on the Rhizophagus irregularis genome assembly (Gloin1 - Tisserant et al., PNAS, 2013) using CLCworkbench suite. Results: -At 1h, a set of 92 fungal genes were found up-regulated in response to wt root exudates (92), not to osnope1 root exudates, many of them being involved in cell signaling. -At 24h and 7d, numerous genes putatively involved in primary metabolism were up-regulated in response to wt root exudates, not in response to osnope1 root exudates -Several vital genes involved in cell development are repressed in response to osnope1 RE compared to wt RE. Conclusions: these results argue for a high metabolic activity induced by wt root exudates, not by osnope1 root exudates.
Project description:This submission comprises all raw sequencing reads generated and/or utilised in the analyses presented in the associated manuscript. The dataset comprises two independent experimental datasets, each designed to address distinct biological questions regarding the transcriptional behaviour of Fusarium oxysporum f. sp. lycopersici (Fol) under varying physiological and conditions of host-interaction. Experiment 1: Raw reads from Fusarium oxysporum f. sp. lycopersici (Fol) grown under four distinct nutrient and substrate conditions: minimal-media broth (Fol-Min-Media), granular microjammed (Gamborg's B5 Microjammed Granular hydrogel), monolithic agarose (Gamborg's B5 in conventional homogeneous agarose), and broth (Gamborg's B5 in liquid). This design enables dissection of transcriptional responses attributable to nutritional composition and substrate mechanical architecture. Experiment 2 Raw reads from a Microjammed Granular hydrogel-based tomato root–Fol infection system. Samples were collected at 12, 24, and 36 hours post-inoculation (hpi). At 12 hpi, tomato root, tip and fungal samples ex-planta surrounding the root surface were profiled. At 24 hpi, tomato root samples and spatially stratified fungal samples collected from ex-planta at the root-proximal and root-distal zones were profiled to characterise host-induced transcriptional rewiring in Fol in proximity to the root surface when the fungus is approaching a host plant before the physical contact. At 36 hpi, only tomato root/tip samples were collected to capture the plant transcriptional responses to infection after establishment of the fungal compatibility within the root.
Project description:We addressed the question how the interaction between the beneficial root endophyte Serendipita vermifera (Sv) and the pathogen Bipolaris sorokiniana (Bs) affects fungal behavior and determines barley host responses using a gnotobiotic natural soil-based split-root system for phenotypic and transcriptional analyses.