| The fungal pathogen Botrytis cinerea causes grey mould in a large number of crops, both before and after harvest. The damage inflicted by grey mould world-wide is in the order of magnitude of 1010-1011 Euro per year. The project aims to unravel the role of the phytohormone ethylene in the interaction of B. cinerea with its host plants, using tomato as a model host. Due to the complex effects of ethylene on host and fungal physiology it is as yet unclear in which manner ethylene influences the infection of plants by B. cinerea. Ethylene is an important compound in plant defence signalling. Its production is subject to auto-induction and feedback inhibition, depending on the concentration and the tissue. Ethylene production precedes and induces fruit ripening or senescence in a range of tissues. Ripe fruit and senescent or wounded plant organs are susceptible to B. cinerea. B. cinerea can produce ethylene. Ethylene may influence B. cinerea germination and/or germ tube elongation. The interplay between the production and the sensing of ethylene, both in the host plant and the pathogen, gives rise to a very complex picture. In order to obtain insight in the roles that ethylene plays for the pathogen in the infection, we will generate fungal mutants and evaluate them in disease assays on wild type and (well-characterised) mutant tomato lines. Four types of B. cinerea mutants will be generated: 1. mutants that are unable to produce ethylene; 2. mutants that over-produce ethylene; 3. mutants that are unable to sense ethylene; 4. mutants in which particular ethylene-responsive genes are deleted. In addition experiments will be done to determine effects of particular pre- or post-harvest treatments on fruit quality and shelf life, to develop a perspective for a reduction of loss due to B. cinerea disease. The proposed research attempts to close the knowledge gap by generating fundamental insight that allows to design rational post-harvest treatments effective against B. cinerea. Tools to evaluate the effectiveness of post-harvest treatments will be developed and post-harvest treatments will be initiated. The information obtained will be exploited to design rational post-harvest treatments on a pilot scale in deliberation with the users. The knowledge generated in the project may lead to different types of utilisation. Optimisation of pre- and post-harvest treatments that result in better product quality. These treatments may either emerge in the area of nutrition supplements or storage conditions. Novel leads to develop (possibly transgenic) plants with improved resistance to B. cinerea. Novel guidelines for cultural practices that may be disseminated to growers. |
