The project aims at providing new knowledge to improve plant resistance to fungal disease moving towards a sustainable agriculture. Botrytis cinerea, the causal agent of grey mold disease, is a broad-spectrum fungal necrotroph that causes serious pre- and post-harvest rot in more than 200 species worldwide. Pectin integrity alteration, pectin methylesterification status, pectin methylesterase (PME) activity and PME-derived damage-associated molecular pattern (DAMPs) such as oligogalacturonides (OGs) and methanol (MeOH) can impact on plant disease resistance. Currently the knowledge on molecular mechanisms underlying PME-mediated immunity is limited. A reverse genetic approach combined with biochemical studies and plant molecular biology will be utilized in Arabidopsis to identify the functional roles of pathogen-responsive PME isoforms induced in response to Botrytis cinerea. Efforts will be devoted to the identification of molecular factors triggering PME expression during infection. Dynamics of CW changes and the subcellular localization of PMEs and PME products will be achieved through advanced confocal microscopy. The release of OGs and MeOH will be investigated through Mass Spectrometry platform. The identification of new genetic determinants underlying pectin integrity maintenance will be useful for obtaining plants with improved resistance to pathogens.
The project aims at providing new knowledge and technological solutions to plant infections caused by fungal pathogens responsible for the most devastating crop diseases. The multidisciplinary work plan will provide advanced knowledge on plant-pathogen interaction. This project will provide novel knowledge on CW biochemical traits useful to increase the long-term plant resistance to fungal pathogens, avoiding the appearance of resistance phenomena and without negative effects in the ecosystem. The project will provide new insight into the regulation of PME activity and to unveil the dynamic of the release of PME-related DAMPs during plant-pathogen interaction.
Botrytis cinerea, the cause of grey mold disease, is considered the second most important fungal plant pathogen at global level (1). This filamentous fungus infects more than 200 plant species in a variety of organs including fruits, flowers, and leaves and 20 % of crop loss worldwide is attributed to this pathogen (UIPP, Annual Report 2012). The large host range, high reproduction rate, broad infections conditions and potential for dissemination make Botrytis spp difficult to control. Application of fungicides is the most commonly used method to control fungal diseases, although it is expensive and not always effective and the risk of fungicide pollution limits their use. Moreover, fungicide resistance is an increasingly problematic issue, with significant proportions of the fungal population being resistant to fungicides. Fungicides specifically targeted against Botrytis (`botryticides¿) cost 540 million of euro, representing 10% of the world fungicide market (1).
Development of resistant cultivars represents a major environmentally friendly solution for both breeders and plant pathologists. The project will provide novel knowledge on biochemical traits and genetic sources to increase the long-term plant resistance to fungal pathogens. Cell wall-based approach to plant disease control in fact, makes possible to avoid the appearance of resistance phenomena in the pathogen populations, without negative effect in the ecosystem. In addition, the pectin methylesterification traits and their underlying genes identified in the project in the Arabidopsis thaliana model plant will represent an excellent tool to identify homologues genes in crop varieties to produce a durable resistance to B. cinerea, either by traditional breeding or by genetic engineering.
The results foreseen in this proposal will have an impact well beyond the species and pathogen here studied: most likely, analogous molecular mechanisms control PME activity during infection with other necrotrophic pathogens and in other crop species. The availability of new resistant genotypes can reduce the need of fungicides and minimize their impact on the environment, ensuring a high standard of plant yield and food quality resulting in a long-term benefit for citizens, economy and society. Taken together all the research activity of the project addresses in a most considerable way to "food security, sustainable agriculture and bio-economy" goals of the tackling social challenge targets. Finally efforts that will be made to provide new experimental tools to analyze, at molecular level, the plant-pathogen interactions.