Project description:The recent release of a large number of genomes from ectomycorrhizal, orchid mycorrhizal and root endophytic fungi have provided deep insight into fungal lifestyle-associated genomic adaptation. Comparative analyses of symbiotic fungal taxa showed that similar outcomes of interactions in distant related root symbioses are examples of convergent evolution. The order Sebacinales represents a sister group to the Agaricomycetes (Basidiomycota) that is comprised of ectomycorrhizal, ericoid-, orchid- mycorrhizal, root endophytic fungi and saprotrophs (Oberwinkler et al., 2013). Sebacinoid taxa are widely distributed from arctic to temperate to tropical ecosystems and are among the most common and species-rich groups of ECM, OM and endophytic fungi (Tedersoo et al., 2012, Tedersoo et al., 2010, Oberwinkler et al., 2013). The root endophyte Piriformospora indica and the orchid mycorrhizal fungus S. vermifera (MAFF 305830) are non-obligate root symbionts which were shown to be able to interact with many different experimental hosts, including the non-mycorrhizal plant Arabidopsis thaliana. These two fungi display similar colonization strategies in barley and in Arabidopsis and the ability to establish beneficial interactions with different hosts (Deshmukh et al., 2006). Colonization of the roots by P. indica and S. vermifera results in enhanced seed germination and biomass production as well as increased resistance against biotic and abiotic stresses in its experimental hosts, including various members of the Brassicaceae family, barley, Nicotiana attenuata and switchgrass (Ghimire, 2011, Ghimire et al., 2009, Ghimire et al., 2011, Waller et al., 2008, Barazani et al., 2007, Deshmukh et al., 2006). Microarray experiments were performed to identify and characterize conserved sebacinoid genes as key determinants in the Sebacinales symbioses.
Project description:Background: The soil environment is responsible for sustaining most terrestrial plant life on earth, yet we know surprisingly little about the important functions carried out by diverse microbial communities in soil. Soil microbes that inhabit the channels of decaying root systems, the detritusphere, are likely to be essential for plant growth and health, as these channels are the preferred locations of new root growth. Understanding the microbial metagenome of the detritusphere and how it responds to agricultural management such as crop rotations and soil tillage will be vital for improving global food production. Methods: The rhizosphere soils of wheat and chickpea growing under + and - decaying root were collected for metagenomics sequencing. A gene catalogue was established by de novo assembling metagenomic sequencing. Genes abundance was compared between bulk soil and rhizosphere soils under different treatments. Conclusions: The study describes the diversity and functional capacity of a high-quality soil microbial metagenome. The results demonstrate the contribution of the microbiome from decaying root in determining the metagenome of developing root systems, which is fundamental to plant growth, since roots preferentially inhabit previous root channels. Modifications in root microbial function through soil management, can ultimately govern plant health, productivity and food security.
Project description:Rhizosphere is a complex system of interactions between plant roots, bacteria, fungi and animals, where the release of plant root exudates stimulates bacterial density and diversity. However, the majority of the bacteria in soil results to be unculturable but active. The aim of the present work was to characterize the microbial community associated to the root of V. vinifera cv. Pinot Noir not only under a taxonomic perspective, but also under a functional point of view, using a metaproteome approach. Our results underlined the difference between the metagenomic and metaproteomic approach and the large potentiality of proteomics in describing the environmental bacterial community and its activity. In fact, by this approach, that allows to investigate the mechanisms occurring in the rhizosphere, we showed that bacteria belonging to Streptomyces, Bacillus and Pseudomonas genera are the most active in protein expression. In the rhizosphere, the identified genera were involved mainly in phosphorus and nitrogen soil metabolism.