Project description:The hemibiotrophic fungal pathogen Colletotrichum graminicola is the causal agent of anthracnose disease on maize stalks and leaves. After the formation of appressoria the host cell wall is penetrated by the conversion of appressorial turgor pressure into forceful ejection of a penetration peg. Subsequently, C. graminicola establishes biotrophic hyphae in the penetrated epidermis cell at around 36 hours post inoculation (hpi) until a switch of hyphal morphology and lifestyle takes place during the colonization of neighboring host cells at around 72 hpi. During the ensuing necrotrophic growth, dark necrotic lesions are formed that are visible as anthracnose symptoms. We used microarrays to detail the global programme of gene expression during the infection process of Colletotrichum graminicola in its host plant to get insight into the defense response of this compatible interaction and into the metabolic reprogramming needed to supply the fungus with nutrients.
Project description:The hemibiotrophic fungal pathogen Colletotrichum graminicola is the causal agent of anthracnose disease on maize stalks and leaves. After the formation of appressoria the host cell wall is penetrated by the conversion of appressorial turgor pressure into forceful ejection of a penetration peg. Subsequently, C. graminicola establishes biotrophic hyphae in the penetrated epidermis cell at around 36 hours post inoculation (hpi) until a switch of hyphal morphology and lifestyle takes place during the colonization of neighboring host cells at around 72 hpi. During the ensuing necrotrophic growth, dark necrotic lesions are formed that are visible as anthracnose symptoms. We used microarrays to detail the global programme of gene expression during the infection process of Colletotrichum graminicola in its host plant to get insight into the defense response of this compatible interaction and into the metabolic reprogramming needed to supply the fungus with nutrients. In three independent experiments, maize plants were infected with conidia of the Colletotrichum graminicola strain CgM2 by spray inoculation of leaves. Samples from infected leaves were taken at 36 and 96 hours post infection, corresponding to initial biotrophic and necrotrophic phase, respectively. Samples from uninfected control plants were taken at the same time points.
Project description:Contrary to the relative wealth of information regarding pathogen defense responses in aboveground plant parts, little is known about the mechanistic basis and regulation of plant immunity in root tissues. Aiming to further our fundamental understanding of root immune responses, we have investigated the interaction between rice and one of its major root pathogens, the oomycete Pythium graminicola. The specificic objectives of this study were twofold: i) to disentangle the molecular and genetic basis of the rice-Pythium interaction by comparing the transcriptome of rice roots at different times after inoculation with a highly virulent Pythium strains, and ii) to offer fundamental insights into the genetic architecture and regulation of rice disease resistance pathways operative in root tissue and to identify the molecular players controlling the possible nodes of convergence between these resistance conduits Comparison between P. graminicola- and mock-infected rice roots. Two treatments (infected and non-infected) x three timepoints (1, 2 and 4 days post inoculation) x three biological replicates