Project description:PAMP (Pathogen-Associated Molecular Pattern) recognition plays an important role in innate immune responses both in plants and animals. Lipopolysaccharides (LPS) of gram-negative bacteria are a typical PAMP molecule and have been reported to induce defense-related responses such as suppression of hypersensitive responses, defense gene espression and systemic resistance in plant. However the detailed analysis of these cellular responses and the molecular machinery involved in the perception and transduction of LPS molecule largely remains to be studied. Furthermore, the biological activities of LPS on plants have so far been reported only for dicots and no information is available on the action of LPS on monocots. We report here that bacterial LPSs, both from plant pathogens and non-pathogens, could induce various defense responses in rice cells, including reactive oxygen generation and defense gene expression. Global analysis of gene expression induced by two PAMP elicitors, LPS and chitin oligosaccharide elicitor, showed a close correlation between the gene responses induced by these elicitors, indicating the convergence of signaling cascades downstream of corresponding receptors. Further, we show that the defense responses induced by LPS are associated with programmed cell death, a finding so far not reported for LPS action on plant cells. Experiment Overall Design: 1. LPS treatment (WT), 2. LPS treatment (WT) color-swap, 3. N-acetylchitooctaose treatment (WT), 4. N-acetylchitooctaose treatment (WT) color-swap
Project description:PAMP (Pathogen-Associated Molecular Pattern) recognition plays an important role in innate immune responses both in plants and animals. Lipopolysaccharides (LPS) of gram-negative bacteria are a typical PAMP molecule and have been reported to induce defense-related responses such as suppression of hypersensitive responses, defense gene espression and systemic resistance in plant. However the detailed analysis of these cellular responses and the molecular machinery involved in the perception and transduction of LPS molecule largely remains to be studied. Furthermore, the biological activities of LPS on plants have so far been reported only for dicots and no information is available on the action of LPS on monocots. We report here that bacterial LPSs, both from plant pathogens and non-pathogens, could induce various defense responses in rice cells, including reactive oxygen generation and defense gene expression. Global analysis of gene expression induced by two PAMP elicitors, LPS and chitin oligosaccharide elicitor, showed a close correlation between the gene responses induced by these elicitors, indicating the convergence of signaling cascades downstream of corresponding receptors. Further, we show that the defense responses induced by LPS are associated with programmed cell death, a finding so far not reported for LPS action on plant cells. Keywords: elicitor, defense, LPS, rice cell
Project description:Seedlings blight is one of the destructive diseases of rice, caused by the fungus Fusarium oxysporum, which impairs rice productions. Fluoro-substituted benzothiadiazole derivatives (FBT) and chitosan oligosaccharide (COS) are elicitors that can enhance plant resistance to pathogen infection. However, there is a lack of information regarding FBT and COS used as elicitors in rice seedlings blight. Therefore, the aim of this study was to evaluate the effect of FBT and COS treatments against rice seedling blight and elucidate the possible molecular mechanisms of the two elicitors for inducing resistance by proteomics. The results showed that FBT and COS significantly reduced the disease incidence and index, and improved the growth status of rice root caused by F. oxysporum. Biochemical analysis demonstrated that the two elicitors effectively enhanced activities of defense enzymes. Moreover, proteomic profiling analysis of rice root tissues disclosed more differentially expressed proteins in diterpenoid biosynthesis pathway induced by the two elicitors compared with other biological pathways, resulting in the accumulation of antimicrobial substance--momilactone. This study provided the basis of theory and application for FBT and COS used as rice elicitors against seedling blight on roots.
Project description:Seedlings of Arabidopsis thaliana Col-0 were treated with a cutin oligomeric mixture (COM) for 30 min. To evaluate if such treatment was able to induce transcriptional reprogramming related with plant immunity. The transcriptomic profiles were compared with those of the Mock treatment. The list of differentially expressed genes was generated to evaluate similarities with the profiles obtained with treatments with well described plant immune elicitors.
Project description:A. thaliana lines with reduced lignin content through down-regulation of the lignin biosynthesis enzymes cinnamoyl CoA reductase (CCR) exhibit extensive cell wall remodeling which results in the release of a mixture of pectic oligosaccharide elicitors of pathogenesis-related (PR) protein gene expression through the salicylic acid signaling pathway. Loss of function of FERONIA, a CrRLK1-like subfamily receptor-like kinase resulted in loss of PR-1, -2 and- 5 gene activation in stems of the ccr1/fer-4 double mutant.
Project description:Root pathogens are a major thread in global crop production and protection strategies are required to sustainably enhance the efficiency of root immunity. Our understanding of root immunity is still limited in comparison to the knowledge gained for the regulation of immune response in leaves. In an effort to reveal the organisation of root immunity in roots, we undertook a cell type-specific transcriptome analysis to identify gene networks in epidermis, cortex and pericycle cells of Arabidopsis roots upon treatment with two immunity elicitors, bacterial microbe-associated molecular pattern flagellin and the endogenous damage-associated molecular pattern Pep1. Our analyses revealed that both elicitors induced cell type-specific immunity gene networks. Interestingly, both elicitors did not alter cell identity determining gene networks. Using sophisticated paired motif promoter analyses, we identified key transcription factor pairs involved in the regulation of cell type-specific immunity networks. In addition, our data show that cell identity networks are liaised with cell immunity networks to activate cell type-specific immune response according to the functional capabilities of each cell type.
Project description:Investigating putative RPS4-chromatin associations during Arabidopsis plant disease resistance, using a temperature-inducible system which resembles pathogen-infection