Secondary metabolites confer a first set of defenses against pathogens and herbivore attack. The use of plant extracts (PE), enriched in these compounds, could represent an additional practice in environment friendly grapevine pest management. During biotic stress, the induction of different pathogenesis-related (PR) gene-expression, such as chitinase, often occurs. In the present work, four different plant extracts were tested for their modulation of chitinase activity in either grapevine suspension cell cultures (GSC) and plants
