Project description:The intention of these gene expression analysis was to study host responses to an infection with Agrobacterium tumefaciens at different stages of crown gall development. Therefore the transcriptome of infected inflorescence stalk tissue and mature crown galls of Arabidopsis thaliana (WS-2) was determined of three different time points. These were compared with the transcriptome of mock-infected inflorescence stalk tissue (reference) of the same age. The following time points were analyzed: (i) three hours post inoculation, before the T-DNA is integrated into the host genome (ii) six days after inoculation when the T-DNA is present in the nucleus and the oncogenes are expressed in the host cell, and (iii) 35 days after inoculation when a mature tumors has developed. For the three-hour- (3hpi) and six-day- time point (6dpi) plants were infected with the virulent strain C58, harboring a T-DNA, or with strain GV3101, containing a disarmed Ti-plasmid. This allows discrimination between signals which derive from the bacterial pathogen and the T-DNA encoded oncogenes. This SuperSeries is composed of the following subset Series:; GSE13929: Arabidopsis thaliana three hours after infection with Agrobacterium tumefaciens; GSE13930: Arabidopsis thaliana six days after infection with Agrobacterium tumefaciens; GSE13927: Transcriptome of mature A. thaliana crown galls. Experiment Overall Design: Refer to individual Series
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: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. 3-week-old A.thaliana Col-0 seedlings were selected for growth in hydroponic systems. A. tumefaciens C58 was inoculated into the hydroponic system and co-cultivation persisted for 8 hours. Leaf tissue was seperated for RNA extraction and hybridization to the ATH1 Affymetrix microarray.
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. 3-week-old A.thaliana Col-0 seedlings were selected for growth in hydroponic systems. A. tumefaciens C58 was inoculated into the hydroponic system and co-cultivation persisted for 8 hours. Root tissue was seperated for RNA extraction and hybridization to the ATH1 Affymetrix microarray.
Project description:This study focuses on responses of the host plant to infection with Agrobacterium tumefaciens. Genome wide changes in gene expression were integrated with the alterations in metabolite levels three hours after inoculation of agrobacteria. Plants were infected with the virulent strain C58, harboring a T-DNA, or with strain GV3101, containing a disarmed Ti-plasmid. This allows discrimination between signals which derive from the bacterial pathogen and the T-DNA encoded genes.
Project description:The pathogen Agrobacterium tumefaciens infects a broad range of plants, introducing the T-DNA into their genome. Contrary to all known bacterial phyto-pathogens, Agrobacterium lacks the hypersensitive response-inducing HRP genes although it introduces numerous proteins into the plant cell through a type IV secretion system. To understand the timing and extent of the plant transcriptional response to this unusual pathogen, we used an Arabidopsis 26-thousand gene oligonucleotide microarray. We inoculated Arabidopsis cell cultures with an oncogenic strain of Agrobacterium and analyzed four biological replicates to identify two robust sets of regulated genes, one induced and the other suppressed. In both cases, the response was distinct at 48 hours after infection, but not at 24 hours or earlier. The induced set includes genes encoding known defense proteins, the repressed set is enriched with genes characteristic of cell proliferation even though a growth arrest was not visible in the inoculated cultures. The analysis of the repressed genes revealed that the conserved upstream regulatory elements Frankiebox (a.k.a. “site II”) and Telobox are associated with the suppression of gene expression. The regulated gene sets should be useful in dissecting the signaling pathways in this plant-pathogen interaction. Keywords: Time-course of Agrobacterium infection
Project description:This study focuses on responses of the host plant to infection and transformation with Agrobacterium tumefaciens. Genome wide changes in gene expression were integrated with the alterations in metabolite levels six days after inoculation of agrobacteria. Plants were infected with the virulent strain C58, harboring a T-DNA, or with strain GV3101, containing a disarmed Ti-plasmid. This allows discrimination between signals which derive from the bacterial pathogen and the T-DNA encoded genes. Experiment Overall Design: The bases of Arabidopsis thaliana (WS-2) inflorescence stalks were wounded and immediately infected with Agrobacterium tumefaciens or mock-infected for six days. Stalks of intact plants were inoculated with the oncogenic strain C58 (C58 6dpi 1 to 3) or the non-virulent strain GV3101 (GV3101 6dpi 1 to 3) to provide conditions close to nature. The gene expression data of three independent experiments of infected material were compared with three non-infected samples (reference 6dpi 1 to 3). Differential gene expression was determined 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/).