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:To further confirm whether the expression of NRT genes were influenced by pathogen infection, maize leaves were sampled at 0h, 24h, 40h, 60h and 96h post inoculation with wild-type strain Colletotrichum graminicola, the causing agent of maize anthracnose disease.
Project description:In compatible interactions, biotrophic microbial phytopathogens rely on the supply of carbon and nitrogen assimilates by the colonized host tissue. Successful biotrophs need to reprogram host metabolism, which also involves the stimulation of assimilate export from living host cells into the plant-pathogen interface at the infection site. In rice and cassava, SWEET sucrose transporters, are induced by bacterial TAL (transcriptional activator-like) effectors to establish compatibility. A pathogen-specific transcriptional induction of SWEET transporters has also been observed in Arabidopsis leaves upon microbial challenge. Here, we have assessed the question, whether the phloem localized AtSWEET11 and AtSWEET12 transporters represent susceptibility factors in the interaction of Arabidopsis with the fungal hemibiotroph Colletotrichum higginsianum (Ch). Compared to wild type, sweet11/sweet12 double mutants exhibited priming of the SA pathway in mock conditions.
Project description:In compatible interactions, biotrophic microbial phytopathogens rely on the supply of carbon and nitrogen assimilates by the colonized host tissue. Successful biotrophs need to reprogram host metabolism, which also involves the stimulation of assimilate export from living host cells into the plant-pathogen interface at the infection site. In rice and cassava, SWEET sucrose transporters, are induced by bacterial TAL (transcriptional activator-like) effectors to establish compatibility. A pathogen-specific transcriptional induction of SWEET transporters has also been observed in Arabidopsis leaves upon microbial challenge. Here, we have assessed the question, whether the phloem localized AtSWEET11 and AtSWEET12 transporters represent susceptibility factors in the interaction of Arabidopsis with the fungal hemibiotroph Colletotrichum higginsianum (Ch). Compared to wild type, sweet11/sweet12 double mutants exhibited priming of the SA pathway in mock conditions. To investigate transcriptional changes in C. higgsinanum infected leaves, five-week old Arabidopsis plants were spray infected with 2 Mio. conidia/ ml 1h before lights off and fully expanded leaves of wild type Col-0 and the sweet11/sweet12 double mutant were harvested in three situations: 1) immediately before treatment, 2) from mock treated plants (sprayed with water) at 2.5 days post treatment and 3) from C. higginsianum inoculated leaves during biotrophic colonization at 2.5 days post treatment
Project description:Species from the genus Colletotrichum are the causal agents of anthracnose which contribute to significant losses to the production of commercially grown crops. The genomes of Colletotrichum orbiculare, which infects cucurbits and Nicotiana benthamiana, as well as Colletotrichum gloeosporioides, which infects a wide range of fruits and vegetables, were sequenced. A custom microarray was designed for Colletotrichum orbiculare and used to assess gene expression during infection of Nicotiana benthamiana. Gene expression of Colletotrichum orbiculare growing on its host Nicotiana benthamiana was assessed at 24 hours post inoculation, 3 days post inoculation and 7 days post inoculation. Mycelia growing in vitro and ungerminated conidia were used as controls. Three replicates were performed for each time point.