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:The aim of our study is to elucidate the gene expression changes in rice in response to colonization by a plant growth promoting rhizobacteria such as the Bacillus subtilis through microarray high throughput technology. In particular, the effect of B.subtilis on root exudation (secretion of phytochemicals through roots) will be analysed. For this rice plantlets were grown in hydroponics and treated with B.subtilis RR4 for 48 hrs. The root samples of the control and treated plants were then used for the microarray experiment. The data obtained through microarray revealed genes related to cell wall modification, phytohormone synthesis, defense response, root exudation, etc. to be differentially regulated in response to B.subtilis RR4. Real time PCR analysis of few chosen genes (OsMS, OsALMT, OsABC, OsSDH, etc) also confirmed the validity of the microarray data. The initial responses of a plant in response to colonization by the microbe will be changes in cell wall of the plant tissues and the secretion of phytochemicals to attract/repel the colonizing beneficial/pathogenic organism. From analysis of microarray data we found the cell wall related genes which aid in root colonization and the root exudate related genes (biosynthesis and transport) which play a role in providing nutrition for the bacterial growth to be differentially regulated significantly. Analysis of specific genes and their biosynthesis pathways indicated that rice plants responded positively to root colonization by B.subtilis RR4. Notable among the exudation related genes such as Malate synthase and ALMT were found to be upregulated which indicates the significant role played by organic acids particularly malate in recruiting the PGPR towards the plant roots. This recruitment will thereby facilitate plant growth. Subsequently, these genes can be engineered in crop plants to recruit beneficial bacteria which might further open new avenues for improved crop production.
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.
Project description:Fairy rings are zones of stimulated grass growth by the interaction between the fungi and the plant. In the previous research, we reported the identification of the M-bM-^@M-^\fairyM-bM-^@M-^], 2-azahypoxanthine (AHX), produced by the fairy ring-forming fungus and the mechanism of its growth-promoting activity using DNA microarray. We discovered AOH, a common metabolite of AHX in plants. We investigate expression profiling of rice seedlings treated with AHX or AOH for the mechanism of their growth-promoting activity. Three-condition experiment, control vs. AHX-treated rice (50 and 200 mM) and AOH-treated rice (50 and 200 mM).
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:Fairy rings are zones of stimulated grass growth by the interaction between the fungi and the plant. In the previous research, we reported the identification of the “fairy”, 2-azahypoxanthine (AHX), produced by the fairy ring-forming fungus and the mechanism of its growth-promoting activity using DNA microarray. We discovered AOH, a common metabolite of AHX in plants. We investigate expression profiling of rice seedlings treated with AHX or AOH for the mechanism of their growth-promoting activity.