The plant cell wall (CW) is a complex and dynamic structure mainly composed of polysaccharides and proteins affecting its mechanical properties, remodeling and disassembly. CW polysaccharides include a cellulose-hemicellulose network embedded in a cohesive pectin matrix . Pectins are synthesized in a highly methylesterified form in Golgi apparatus and demethylesterified in muro by pectin methylesterases (PMEs). PMEs play a central role in controlling CW integrity in plant growth and resistance to pathogens. In addition to the transcriptional control, PME activity is finely regulated by two classes of proteins: PME-specific subtilases (SBTs) and PME inhibitors (PMEIs). PMEs, PMEIs and SBTs belongs to large multigene families subdivided in subfamilies based on sequence similarity and including members possibly sharing common biological functions. Recent evidences indicate the role of pathogen-induced PMEs in plant immunity.
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 including important fruit crops. The aim of the project is to study the role of PME17 a PME isoform, strongly induced by B.cinerea in plant immunity. In particular we will focus on PME17 regulation by specific PMEIs and SBTs isoforms in response to B. cinerea to identify new candidate genes involved in resistance to pathogens.
Cross-disciplinary and innovative approaches of cell biology, biochemistry, glycomics and functional genomics will be exploited on genotypes of Arabidopsis thaliana altered in PME activity and resistance to B.cinerea. Our findings, will be extended to Vitis vinifera , an important crop species sensitive to B.cinerea, to aid the identification of cell wall biochemical markers useful for a future selection of cultivars improved in resistance to pathogens and in food quality.