Project description:Agrobacterium tumefaciens, a bacterial species found in temperate soils world wide, is the causative agent of crown gall disease on many plants. A. tumefaciens-induced tumours are feared in orchards and vineyards because of their pathological interference with nutrient and water supply which results in crop decline. Small wounds at the crown of the plant, usually induced by wind-bending, are potential entry sites for the bacterium. The tumorous growth is initiated by the integration and expression of the T-DNA of the bacterial Ti plasmid within the plant nuclear DNA. The T-DNA encodes enzymes catalysing the synthesis of increased concentrations of auxin and cytokinin, and of opines which stimulate cell division and enlargement. The fast growing tumours have been shown to be a strong nutrient sink on their host plants. As a matter of fact, sugar and K+ content were found to be up to 10- and 5-fold, respectively, higher in this tissue and transpiration was about 15 times increased compared to normal tissue. Whereas the morphological structure as well as some physiological and biochemical parameters of the tumour have been analysed in detail, little is known about the underlying gene expression pattern. Proliferation and growth of the tumour induced by Agrobacterium tumefaciens is obviously due to the extraordinary high concentration of phytohormons, minerals and metabolites. Their influence on regulation of gene transcription will provide information on the mechanisms underlying fast tumour growth. In a project funded by the DFG we recently started to investigate the role of solute transporter for tumour development on the model plant Arabidopsis thaliana. By comparing the expression pattern of RNA preparations from Arabidopsis tumour and non-tumour tissue, we will be able to identify genes which facilitate crown gall development. For the expression analysis with an Affymetrix full genome chip we will induce tumours at the base of an injured Arabidopsis inflorescence stalk (var. Wassilewskija, WS-2). RNA will be extraxted from tumour and injured non-tumor inflorescence stalk tissue using the RNeasy Plant Mini Kit (Qiagen), followed by a DNase treatment to eliminate DNA contamination. This Series record represents a partial dataset. The complete dataset was submitted under GEO accession number GSE13927. Experimenter name = Rosalia Deeken Experimenter phone = +49 931 8886121 Experimenter fax = +49 931 8886158 Experimenter institute = Julius-von-Sachs-Institute of Biosciences Molecular Plant Physiology and Electrophysiology Experimenter address = Julius-von-Sachs-Platz 2 Experimenter address = Wuerzburg Experimenter zip/postal_code = D-97082 Experimenter country = Germany Keywords: pathogenicity_design
Project description:This study describes physiological changes, morphological adaptations and the regulation of pathogen defense responses in Arabidopsis crown galls. Crown gall development was induced on intact plants under most natural conditions with Agrobacterium tumefaciens. Differential gene expression and the metabolite pattern was determined by comparing crown galls with mock-inoculated inflorescence stalk segments of the same age. Experiment Overall Design: The bases of Arabidopsis thaliana (WS-2) inflorescence stalks were wounded and immediately inoculated with Agrobacterium tumefaciens, strain C58, or mock-inoculated. Plants were cultivated for another 35 days under short day conditions (8 h illumination, 16 h darkness). Gene expression values of four independent experiments of treated material (C58 35dpi 1 to 4) were compared with four non-treated samples of the same age (reference 35dpi 1 to 4). Differential gene expression was analyzed by applying the LIMMA package (Linear Models for Microarray Data; Smyth, G.K. (2004) Applic. Genet. Mol. Biol. 3, Article 3; http://www.bepress.com/sagmb/vol3/iss1/art3/).
Project description:This study describes physiological changes, morphological adaptations and the regulation of pathogen defense responses in Arabidopsis crown galls. Crown gall development was induced on intact plants under most natural conditions with Agrobacterium tumefaciens. Differential gene expression and the metabolite pattern was determined by comparing crown galls with mock-inoculated inflorescence stalk segments of the same age.
Project description:As sessile organisms, plants require dynamic pathways in order to recognize pathogens and coordinate plant defenses by signalling. Agrobacterium tumefaciens C58 is able to avoid triggering plant defenses prior to entering the cell, and therefore is only detected once infection has begun making Agrobacterium a plant pathogen to numerous plant species. Understanding plant responses to Agrobacterium will be useful in improving plant defenses and potentially may also improve plant transformation efficiency. Microarrays were utilized for detailing the global gene expression pattern in A. thaliana Col-0 roots in response to A. tumefaciens C58 for the identification of differentially expressed genes.
Project description:As sessile organisms, plants require dynamic pathways in order to recognize pathogens and coordinate plant defenses by signalling. Agrobacterium tumefaciens C58 is able to avoid triggering plant defenses prior to entering the cell, and therefore is only detected once infection has begun making Agrobacterium a plant pathogen to numerous plant species. Understanding plant responses to Agrobacterium will be useful in improving plant defenses and potentially may also improve plant transformation efficiency. Microarrays were utilized for detailing the global gene expression pattern in A. thaliana Col-0 leafs in response to A. tumefaciens C58 for the identification of differentially expressed genes.
Project description:Agrobacterium tumefaciens, a bacterial species found in temperate soils world wide, is the causative agent of crown gall disease on many plants. A. tumefaciens-induced tumours are feared in orchards and vineyards because of their pathological interference with nutrient and water supply which results in crop decline. Small wounds at the crown of the plant, usually induced by wind-bending, are potential entry sites for the bacterium. The tumorous growth is initiated by the integration and expression of the T-DNA of the bacterial Ti plasmid within the plant nuclear DNA. The T-DNA encodes enzymes catalysing the synthesis of increased concentrations of auxin and cytokinin, and of opines which stimulate cell division and enlargement. The fast growing tumours have been shown to be a strong nutrient sink on their host plants. As a matter of fact, sugar and K+ content were found to be up to 10- and 5-fold, respectively, higher in this tissue and transpiration was about 15 times increased compared to normal tissue. Whereas the morphological structure as well as some physiological and biochemical parameters of the tumour have been analysed in detail, little is known about the underlying gene expression pattern. Proliferation and growth of the tumour induced by Agrobacterium tumefaciens is obviously due to the extraordinary high concentration of phytohormons, minerals and metabolites. Their influence on regulation of gene transcription will provide information on the mechanisms underlying fast tumour growth. In a project funded by the DFG we recently started to investigate the role of solute transporter for tumour development on the model plant Arabidopsis thaliana. By comparing the expression pattern of RNA preparations from Arabidopsis tumour and non-tumour tissue, we will be able to identify genes which facilitate crown gall development. For the expression analysis with an Affymetrix full genome chip we will induce tumours at the base of an injured Arabidopsis inflorescence stalk (var. Wassilewskija, WS-2). RNA will be extraxted from tumour and injured non-tumor inflorescence stalk tissue using the RNeasy Plant Mini Kit (Qiagen), followed by a DNase treatment to eliminate DNA contamination.