Project description:Ustilago maydis is a plant-pathogenic fungus that establishes a biotrophic relationship with its host Zea mays. The biotrophic interaction is initiated upon host penetration, and involves expansion of the host plasma membrane around hyphae, which is thought to facilitate the exchange of nutrients and virulence factors. Transcriptional regulators involved in the establishment of an infectious dikaryon and penetration into the host have been identified, however, regulators involved in the post-penetration stages remained to be elucidated. In the study we report the identification of an Ustilago maydis forkhead transcription factor, Fox1, which is exclusively expressed during biotrophic development. Deletion of fox1 results in reduced virulence and impaired tumour development in planta. Δfox1 hyphae induce plant defences including the overproduction and accumulation of H2O2 in and around infected cells. This oxidative burst acts as an intercellular signal, which elicits a specific host defence response phenotypically represented by the encasement of proliferating hyphae in extensions of the plant cell wall. Maize microarrays experiments were performed to identify genes involved in the observed plant defence responses on leaf tissue infected with U. maydis strain SG200∆fox1 4 dpi.
Project description:Investigation of whole genome gene expression level in Pseudozyma antarctica T-34, compared to Ustilago maydis UM521. To clarify the transcriptomic characteristics of Pseudozyma antarctica under the conditions of high MEL production, a DNA microarray of both the strains, Pseudozyma antarctica T-34 and Ustilago maydis UM521 was prepared and analyzed the transcriptomes. A DNA chip study using mRNA from the cultures of Pseudozyma antarctica T-34 and Ustilago maydis UM521 demonstrated the gene expression level of each strain.
Project description:Gene expression of FB2 wt in minimal medium with 2 percent arabinose or glucose after 24h of growth was compared with the conditional promoter regulated strain Pcrg1:grx4 (#55). Glucose is a repressor of this promoter while arabinose acts as inducer. Grx4 was initially pre-depleted during growth on MM with glucose over night. Afterwards cells were transferred to MM with either glucose or arabinose and cells were collected after 24h. 3 biological repeats were performed for each strain and each condition. Cells were flash frozen and used to isolate total RNA. RNA sequencing was done by Genewiz. DEG’s between wt and mutant for the different conditions were obtained. Iron regulated genes such as the high affinity uptake system and the siderophore system of Ustilago maydis were repressed in the Pcrg1:grx4 (#55) strain when grown in glucose. Expression of these genes were similar for wt and the conditional strain when grown in arabinose. Grx4 was identified as an essential gene in Ustilago maydis which regulates the iron regulon and related genes.
