Project description:Plants have developed a complicated resistance system, and they exhibit various defense patterns in response to different attackers. However, the determine factors of plant defense patterns are still not clear. Here, we hypothesized that damage patterns of plant attackers play an important role in determining the plant defense patterns. To test this hypothesis, we selected leafminer, which has a special feeding pattern more similar to pathogen damage than chewing insects, as our model insect, and Arabidopsis thaliana as the response plants. The local and systemic responses of Arabidopsis thaliana to leafminer feeding were investigated using the Affymetrix ATH1 genome array.
Project description:Plants have developed a complicated resistance system, and they exhibit various defense patterns in response to different attackers. However, the determine factors of plant defense patterns are still not clear. Here, we hypothesized that damage patterns of plant attackers play an important role in determining the plant defense patterns. To test this hypothesis, we selected leafminer, which has a special feeding pattern more similar to pathogen damage than chewing insects, as our model insect, and Arabidopsis thaliana as the response plants. The local and systemic responses of Arabidopsis thaliana to leafminer feeding were investigated using the Affymetrix ATH1 genome array. Damaged leaves of Arabidopsis thaliana for local damage analysis and the intact leaves on the same plant for systemic damage analysis were separately frozen by liquid nitrogen. Then, we used an Affymetrix ATH1 Arabidopsis microarray to study the expression changes pattern of Arabidopsis thaliana to pea leafminers damage, both locally (LI) and systemically (SI). We downloaded data from the web database and used hierarchical clustering to explore the relationships of Arabidopsis thaliana expression pattern to different kinds of attackers.
Project description:DCA (3,5-Dichloroanthranilic acid) is a newly identified synthetic defense elicitor. To perform a comparative analysis of defense responses triggered by DCA and the structurally related defense inducer INA (2,6-Dichloroisonicotinic acid) Affymetrix chip experiments were performed with Arabidopsis thaliana seedlings treated with one of these two compounds.
Project description:We have implemented an integrated Systems Biology approach to analyze overall transcriptomic reprogramming and systems level defense responses in the model plant Arabidopsis thaliana during an insect (Brevicoryne brassicae) and a bacterial (Pseudomonas syringae pv. tomato strain DC3000) attack. The main aim of this study was to identify the attacker-specific and general defense response signatures in the model plant Arabidopsis thaliana while attacked by phloem feeding aphids or pathogenic bacteria. Defense responses and networks, unique and specific for aphid or Pseudomonas stresses were identified. Our analysis revealed a probable link between biotic stress and microRNAs in Arabidopsis and thus opened up a new direction to conduct large-scale targeted experiments to explore detailed regulatory links among them. The presented results provide a first comprehensive understanding of Arabidopsis - B. brassicae and Arabidopsis - P. syringae interactions at a systems biology level.
Project description:We have implemented an integrated Systems Biology approach to analyze overall transcriptomic reprogramming and systems level defense responses in the model plant Arabidopsis thaliana during an insect (Brevicoryne brassicae) and a bacterial (Pseudomonas syringae pv. tomato strain DC3000) attack. The main aim of this study was to identify the attacker-specific and general defense response signatures in the model plant Arabidopsis thaliana while attacked by phloem feeding aphids or pathogenic bacteria. Defense responses and networks, unique and specific for aphid or Pseudomonas stresses were identified. Our analysis revealed a probable link between biotic stress and microRNAs in Arabidopsis and thus opened up a new direction to conduct large-scale targeted experiments to explore detailed regulatory links among them. The presented results provide a first comprehensive understanding of Arabidopsis - B. brassicae and Arabidopsis - P. syringae interactions at a systems biology level.
Project description:Belonging to the Carmovirus family, Turnip crinkle virus (TCV) is a positive-strand RNA virus that can infect Arabidopsis. Most Arabidopsis ecotypes are highly susceptible to TCV, except for the TCV resistant line Di-17 derived from ecotype Dijon. Previous studies showed that many of the stress related genes have changed significantly after TCV infection. Besides the virus-triggered genes, small RNAs also play critical roles in plant defense by triggering either transcriptional and/or post-transcriptional gene silencing. In this study, TCV-infected wildtype Arabidopsis thaliana and dcl1-9 mutant plants were subjected to transcriptome and small RNA analysis to investigate the role of DCL1 in virus defense network.
Project description:Plant microRNAs (miRNAs) have been implicated in plant immunity. These mainly focusing Arabidopsis thaliana threatened by (hemi-)biotrophic pathogens such as the bacterial pathogen Pseudomonas syringae. Here, we show that the Arabidopsis miRNA pathway is important for defense responses against the necrotrophic fungus Alternaria brassicicola. The miRNA pathway mutant ago1 exhibits an exaggerated response when treated with A. brassicicola, proposing that AGO1 is positive regulator. We found a subset of Arabidopsis miRNAs that quickly change their expression and their abundance in AGO1 complexes in plants exposed to A. brassicicola. The miRNAs responding to pathogen treatment are mainly targeting genes encoding metabolic enzymes, proteins involved protein degradation or transposons. In case of miR163, A. brassicicola infection results in increased levels of miRNA precursors and preferential accumulation of an unspliced form of pri-miR163, suggesting that A. brassicicola infection changes the transcriptional and post-regulation of pri-miRNAs. miR163 acts as a negative regulator of plant defense because mir163 mutants are more resistant when treated with A. brassicicola. Taken together, our results reveal the existence of positively and negatively acting Arabidopsis miRNA modulating the defense responses against A. brassicicola and highlight the importance of host miRNAs in the interaction between plants and necrotrophic pathogens.
Project description:Belonging to the Carmovirus family, Turnip crinkle virus (TCV) is a positive-strand RNA virus that can infect Arabidopsis. Most Arabidopsis ecotypes are highly susceptible to TCV, except for the TCV resistant line Di-17 derived from ecotype Dijon. Previous studies showed that many of the stress related genes have changed significantly after TCV infection. Besides the virus-triggered genes, small RNAs also play critical roles in plant defense by triggering either transcriptional and/or post-transcriptional gene silencing. In this study, TCV-infected wildtype Arabidopsis thaliana and dcl1-9 mutant plants were subjected to transcriptome and small RNA analysis to investigate the role of DCL1 in virus defense network.