Project description:Identification of genes differentially expressed in roots of Arabidopsis Col-0 and ndr1-1 mutants 48 h post inoculation with the fungal pathogen Verticillium longisporum.
Project description:Verticillium longisporum is a soil-borne fungal pathogen causing vascular disease predominantly in oilseed rape. The pathogen enters its host through the roots and entertains a parasitic life stage in the xylem before invading other tissues late in the infection cycle. We have started to approach the question how and when the host plant senses the colonization of the xylem using Arabidopsis thaliana as a model plant. Although the stress-related phytohormones salicylic acid, jasmonic acid and abscisic acid increase only at 28 to 35 days, expression of V. longisporum-induced genes (VliGs) starts in the leaf veins as early as 5 dpi when disease symptoms and fungal DNA cannot yet be detected. It is concluded that an elicitor is transported from the root to the aerial parts. More than one third of the VliGs identified by whole genome expression profiling at 18 dpi encode apoplastically localized proteins involved in cell wall modifications and potential defense responses. The identified VliGs provide a useful tool to elucidate the contribution of the induced genes to the disease phenotype and the defense response. Moreover, they will help to identify the elicitor(s) and the components of the signal transduction chain that shape the V. longisporum – plant interaction. Keywords: Arabidopsis, cell wall, microarray, phytohormones, Verticillium longisporum, xylem
Project description:Plant pathogens secrete distinct effector molecules in their host plants to establish successful infections. Verticillium longisporum colonizes the vascular system of the plant. We analyzed the exoproteome of the fungus dependent on different environmental conditions including non plant-related and plant-related environments. This exoproteomic comparison led to the identification of a set of proteins that are specifically secreted in the xylem sap.
Project description:Plant roots secrete secondary metabolites to sense the enviroment around them. Among them, terpenes play a prominent role. Terpenes can have either fungistatic or fungicide action. However, their exact role in plant-host interactions is not fully understood. Verticillium longisporum is a soilborne pathogen causing disease in Brasicacae plants. In this project we investigated the transcriptomic changes of this species upon exposure to the β-pinene monoterpene in different time points 0hpi, 8hpi, 24hpi and 24hpi.
Project description:Identification of genes differentially expressed in roots of Arabidopsis Col-0 and ndr1-1 mutants 48 h post inoculation with the fungal pathogen Verticillium longisporum. Arabidopsis Col-0 and ndr1-1 seeds were grown in petri dishes with liquid MS medium supplemented with 0.2% sucrose. After two weeks on a horizontal shaker (40 rpm), plants were rinsed twice in sterile distilled water and transferred to liquid 0.5xMS medium without sucrose, supplemented with 200 conidia ml-1 of V. longisporum isolate VL1 (CBS110220). Control plants were grown in 0.5x MS only. At 48 hours post inoculation, materials were harvested in biological replicates (>50 plant roots) and immediately frozen in liquid nitrogen. RNA was extracted with Aurum Total RNA Mini Kit (Bio-Rad) and hybridized to the Arabidopsis ATH1 Genome Array at the DNAVision facility (Gosselies, Belgium). Microarray assays were performed with triplicate biological root samples. Normalization of the microarray data was performed using the Robust Multichip Average (RMA) method as implemented by the “quantile normalization” function in the Bioconductor 1.3 software.
