FINDING NOVEL VIRULENCE FACTORS BY AN EPIGENETICS APPROACH
Abstract
Host-pathogen interactions constitute fine-tuned interplays where each of the participating organism has evolved efficient strategies to win over the other. Here, epigenetic variations of pathogenesis (pathogen) and resistance (host) genes likely contribute to the phenotypic diversity and pathogen/host adaptation, and thus, may explain how both organisms rapidly and permanently adapt to these challenging conditions. Epigenetic mechanisms include histone posttranscriptional modifications (HPTMs) that do not alter the DNA sequence, but affect the read out thereof. Depending on the kind of HPTM the underlying genes are either turned on or off, suggesting that the fungal epigenetic landscape is a crucial determinant for successful host invasion. Only a limited number of studies have so far looked into this aspect of fungal-host interactions and they have found that many epigenetic mutants are affected in virulence. Study of these strains has proven to be a powerful tool to reveal novel virulence-associated genes In the proposed research project, entitled ‘Finding novel virulence factors by using an epigenetics approach’, we will focus on the so far not well characterised interaction of Fusarium fujikuroi with its host plant rice (Oryza sativa). F. fujikuroi is the causal agent of bakanae disease (chlorosis and hyperelongation) on rice resulting in huge crop losses. Some - but not all - symptoms of the disease are related to the production of the plant hormone gibberellic acid (GA) by the pathogen. Not much is known, however, regarding GA-independent virulence factors in this pathosystem. F. fujikuroi has at least 46 additional natural products, suggesting that others might also contribute to the fungal virulence. Comparison of mutant strains with an altered HPTM profile as well as affected in virulence and non-mutated strains will likely reveal genes that normally respond to the epigenetic change conveyed by the respective HPTM during the infection. Genome-wide analysis of gene expression in mutants affected in virulence will be performed during the infection and compared to the wild type. Genes associated with the infection are likely to be among the set of differentially regulated genes, and thus, will likely enable identification of virulence-associated genes. To directly correlate the changes in the gene regulation with the chromatin status we will employ Chromatin immunoprecipitation (ChIP) of the fungal chromatin during the pathogenic growth (in planta ChIP), thereby shedding light on the epigenetic mechanisms that take place during the fungal-plant interaction. A small set of target genes that show this significant correlation between changes in transcriptional activity and epigenetic marks will be chosen for a more detailed functional characterisation. This project will reveal new basic information on the epigenetic regulatory level of the fungal pathogen interaction with a host plant.
keywords Fusarium epigenetics rice
Publikationen
Project staff
Lena Studt-Reinhold
Dr.in Lena Studt-Reinhold
lena.studt-reinhold@boku.ac.at
Tel: +43 1 47654-94493
Project Leader
01.02.2017 - 31.12.2020