Project description:Most vascular flowering plants have the ability to form mutualistic associations with soil fungi from the Glomeromycota. The resulting symbiosis is called an arbuscular mycorrhiza and they are widespread in terrestrial ecosystems throughout the world. Although the physical interaction between the symbionts occurs in the root cortex, the symbiosis impacts the physiology of the whole plant. To gain a better understanding of the AM symbiosis, we have used the 16000 feature array to examine gene expression in the leaves of mycorrhizal plants to explore the transcriptional changes that are triggered systemically as a result of the AM symbiosis. Keywords: Medicago truncatula, Mycorrhizal, systemic regulation, microarray profiling
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:Most vascular flowering plants have the ability to form mutualistic associations with soil fungi from the Glomeromycota. The resulting symbiosis is called an arbuscular mycorrhiza and they are widespread in terrestrial ecosystems throughout the world. Significant alteration occurs at physiological and molecular levels in both symbionts. To gain a better understanding of the AM symbiosis, we use a 16000 feature oligonucleotide based array to examine gene expression in an arbuscular mycorrhizal symbioses, M. truncatula/Gigaspora gigantea. Keywords: Medicago truncatula, Mycorrhizal, Gigaspora gigantea, microarray profiling
Project description:Most vascular flowering plants have the ability to form mutualistic associations with soil fungi from the Glomeromycota. The resulting symbiosis is called an arbuscular mycorrhiza and they are widespread in terrestrial ecosystems throughout the world. Significant alteration occurs at physiological and molecular levels in both symbionts. To gain a better understanding of the AM symbiosis, we use a 16000 feature oligonucleotide based array to examine gene expression in an arbuscular mycorrhizal symbioses, M. truncatula/G. intraradices. Keywords: Medicago truncatula, Mycorrhizal, Glomus intraradices, microarray profiling
Project description:High ambient temperature regulated the plant systemic response to the beneficial endophytic fungus Serendipita indica. Most plants in nature establish symbiotic associations with endophytic fungi in soil. Beneficial endophytic fungi induce a systemic response in the aboveground parts of the host plant, thus promoting the growth and fitness of host plants. Meanwhile, temperature elevation from climate change widely affects global plant biodiversity as well as crop quality and yield. Over the past decades, great progresses have been made in the response of plants to high ambient temperature and to symbiosis with endophytic fungi. However, little is known about their synergistic effect on host plants. The endophytic fungus Serendipita indica colonizes the roots of a wide range of plants, including Arabidopsis. Based on the Arabidopsis-S. indica symbiosis experimental system, we analyzed the synergistic effect of high ambient temperature and endophytic fungal symbiosis on host plants. By transcriptome analysis, we found that DNA replication-related genes were significantly upregulated during the systemic response of Arabidopsis aboveground parts to S. indica colonization. Plant hormones, such as jasmonic acid (JA) and ethylene (ET), play important roles in plant growth and systemic responses. We found that high ambient temperature repressed the JA and ET signaling pathways of Arabidopsis aboveground parts during the systemic response to S. indica colonization in roots. Meanwhile, PIF4 is the central hub transcription factor controlling plant thermosensory growth under high ambient temperature in Arabidopsis. PIF4 is also involving JA and/or ET signaling pathway. We found that PIF4 target genes overlapped with many differentially expressed genes (DEGs) during the systemic response, and further showed that the growth promotion efficiency of S. indica on the pif4 mutant was higher than that on the wild type plants.
Project description:Many plants associate with arbuscular mycorrhizal fungi for nutrient acquisition, while legumes also associate with nitrogen-fixing rhizobial bacteria. Both associations rely on symbiosis signaling and here we show that cereals can perceive lipochitooligosaccharides (LCOs) for activation of symbiosis signaling, surprisingly including Nod factors produced by nitrogen-fixing bacteria. However, legumes show stringent perception of specifically decorated LCOs, that is absent in cereals. LCO perception in plants is activated by nutrient starvation, through transcriptional regulation of Nodulation Signaling Pathway (NSP)1 and NSP2. These transcription factors induce expression of an LCO receptor and act through the control of strigolactone biosynthesis and the karrikin-like receptor DWARF14-LIKE. We conclude that LCO production and perception is coordinately regulated by nutrient starvation to promote engagement with mycorrhizal fungi. Our work has implications for the use of both mycorrhizal and rhizobial associations for sustainable productivity in cereals.
Project description:To investigate the involvement of arbuscular mycorrhizal symbiosis in the moleular regulation in foxtail millet roots and the effects of genetic variation on AMS-mediated molecular regulation, we isolated total RNA from the roots of 3 different landraces for comprehensive transcriptomic analysis. We then performed gene expression profiling analysis using data obtained from RNA-seq of 3 different landraces (Hanevalval, TT8, ICE36) after 6-week mock or arbuscular mycorrhizal fungi treatments.
Project description:Arbuscular mycorrhizal symbiosis is a predominant relationship between plant and arbuscular mycorrhizal fungi. To idendify arbuscular mycorrhiza responsive miRNAs, small RNA libraries were constructed in tomato roots colonized with Rhizophagus irregularis and without Rhizophagus irregularis. We identify miRNAs in tomato roots and provide a new profile of tomato miRNAs. And we found that some miRNAs were responsive to arbuscular mycorrhiza by comparing miRNAs in treatment with that in control.
Project description:Arbuscular mycorrhizal (AM) fungi contribute to plant nutrient uptake in systems managed with reduced fertilizer inputs such as organic agriculture and natural ecosystems by extending the effective size of the rhizosphere and delivering mineral. Connecting the molecular study of the AM symbiosis with agriculturally- and ecologically-relevant field environments remains a challenge and is a largely unexplored research topic. This study utilized a cross-disciplinary approach to examine the transcriptional, metabolic, and physiological responses of tomato (Solanum lycopersicum) AM roots to a localized patch of nitrogen (N). A wild-type mycorrhizal tomato and a closely-related nonmycorrhizal mutant were grown at an organic farm in soil that contained an active AM extraradical hyphal network and soil microbe community. The majority of genes regulated by upon enrichment of nitrogen were similarly expressed in mycorrhizal and nonmycorrhizal roots, suggesting that the primary response to an enriched N patch is mediated by mycorrhiza-independent root processes. However where inorganic N concentrations in the soil were low, differential regulation of key tomato N transport and assimilation genes indicate a transcriptome shift towards mycorrhiza-mediated N uptake over direct root supplied N. Furthermore, two novel mycorrhizal-specific tomato ammonium transporters were also found to be regulated under low N conditions. A conceptual model is presented integrating the transcriptome response to low N and highlighting the mycorrhizal-specific ammonium transporters. These results enhance our understanding of the role of the AM symbiosis in sensing and response to an enriched N patch, and demonstrate that transcriptome analyses of complex plant-microbe-soil interactions provide a global snapshot of biological processes relevant to soil processes in organic agriculture. 30 samples were analyzed. There were 2 genotypes (wildtype and mutant) and 3 treatments (two N treatments and a water control) for a total of 6 groups. Each group had 5 biological replicates.
Project description:Most land plants form beneficial associations with arbuscular mycorrhizal (AM) fungi which improves mineral nutrition, mainly phosphorus and nitrogen in the host plant in exchange for photosynthetically fixed carbon. Most of our knowledge on the AM symbiosis derives from dicotyledonous species. We show that inoculation with the AM fungus Funneliformis mossease stimulates growth and increases Pi content in leaves of the rice cultivar Loto (O. sativa ssp japonica). Although rice is a host for AM fungi, the molecular mechanism underlying the AM symbiosis, in particular the systemic transcriptional responses of shoots to AM inoculation, remain largely elusive. Transcript profiling of the shoots indicated the systemic induction of genes involved in the biosynthesis of phospholipids (phosphoinositides, inositol polyphosphates) and down-regulation of non-phosphorus lipids (galactolipids, sulfolipids) in leaves of mycorrhizal rice. Regulation of phospholipid biosynthesis genes appears to be coordinated with a reduced expression of genes involved in jasmonic acid and ethylene biosynthesis and signaling. Genes involved in phosphate starvation responses and remobilization of Pi were also found to be down-regulated in leaves of mycorrhizal rice. These results demonstrated that the AM symbiosis is accompanied by complex alterations in gene expression in shoots which are potentially important to maintain a stable symbiotic relationship in rice plants.