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:Arabidopsis thaliana 4-day-old seedlings were treated with the plant growth promoting rhizobacteria Caulobacter RHG1 or the neutral bacteria Bacillus sp. At 12 and 48 hours after treatment, roots were harvested, RNA was extracted and RNA-Seq data were generated. The goal of this experiment was to detect changes at the transcript level that were specific for the plant growth promoting rhizobacteria RHG1.
Project description:Piriformospora indica, an endophytic fungus of Sebacinales, colonizes the roots of many plant species including Arabidopsis thaliana. The symbiotic interaction promotes plant per-formance, growth and resistance/tolerance against abiotic and biotic stress. We demonstrate that exudated compounds from the fungus activate stress and defense responses in the Arabidopsis roots and shoots before the two partners are in physical contact. They induce stomata closure, stimulate reactive oxygen species (ROS) production, stress-related phytohormone accumulation and activate defense and stress genes in the roots and/or shoots. Once a physical contact is established, the stomata re-open, ROS and phytohormone levels decline, and the gene expression pattern indicates a shift from defense to mutualistic interaction. We propose that exudated compounds from P. indica induce stress and defense responses in the host. Root colonization results in the downregulation of defense responses and the activation of genes involved in promoting plant growth, metabolism and performance.
Project description:H. seropedicae is a diazotrophic and endophytic bacterium that associates with economically important grasses promoting plant growth and increasing productivity. To identify genes related to bacterial ability to colonize and promote plant growth wheat seedlings growing hydroponically in Hoaglandâs medium were inoculated with H. seropedicae the bacteria and incubated for 3 days. mRNA from the bacteria present in the root surface and in the plant medium were purified, depleted from rRNA and used for RNA-seq profiling. RT-qPCR analyses were conducted to confirm regulation of selected genes. Comparison of RNA profile of bacteria attached to the root and planktonic revealed an extensive metabolic adaptation to the epiphytic life style.
Project description:Plant growth-promoting rhizobacteria (PGPR) are soil beneficial microorganisms that colonize plant roots for nutritional purposes and accordingly benefit plants by increasing plant growth or reducing disease. But it still remains unclear which mechanisms or pathways are involved in the interactions between PGPR and plants. To understand the complex plant-PGPR interactions, the changes in the transcriptome of typical PGPR standard Bacillus subtilis in responding to rice seedlings were analyzed. We compared and anylyzed the transcriptome changes of the bacteria Bacillus subtilis OKB105 in response to rice seedings for 2 h. Total RNA was extracted and Random priming cDNA synthesis, cDNA fragmentation and terminal labeling with biotinylated GeneChip DNA labeling reagent, and hybridization to the Affymetrix GeneChip Bacillus subtilis Genome Array.
Project description:Endophytic fungi are root-inhabiting fungi that can promote plant growth in a variety of ways. They can directly stimulate plant growth by producing phytohormones, such as auxin and gibberellins. They can also indirectly promote plant growth by helping plants to acquire nutrients, such as nitrogen and phosphorus, and by protecting plants from pests and pathogens.In this study, we used a proteomic approach to identify the proteins that are expressed in rice plants after they are treated with endophytic fungi. We found that the treatment with endophytic fungi resulted in the expression of a number of proteins involved in plant growth, nutrient acquisition, and defense. These results suggest that endophytic fungi can promote plant growth and improve plant resilience to stress.
Project description:Root exudates play an important role in plant-microbe interaction. The transcriptional profilings of plant growth-promoting rhizobacteria Bacillus amyloliquefaciens SQR9 in response to maize root exudates under static condition, were investigated by an Illumina RNA-seq for understanding the regulatory roles of the root exudates.
Project description:Plant growth-promoting rhizobacteria (PGPR) are soil beneficial microorganisms that colonize plant roots for nutritional purposes and accordingly benefit plants by increasing plant growth or reducing disease. But it still remains unclear which mechanisms or pathways are involved in the interactions between PGPR and plants. To understand the complex plant-PGPR interactions, the changes in the transcriptome of typical PGPR standard Bacillus subtilis in responding to rice seedlings were analyzed.