Detection of Defense Response Elicitor against a Fungal Disease in Strawberry

CHALFOUN NADIA REGINA; SALAZAR SERGIO MIGUEL; CASTAGNARO ATILIO PEDRO; DÍAZ RICCI JUAN CARLOS

San Carlos de Bariloche, Argentina

Congreso; XXXIX Reunión Anual SAIB - XXXII Reunión SAB - Bariloche Protein Symposium; 2003

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

Plants and pathogens have coevolved in the competence to defeat themselves by using highly specific attack and defense strategies. When plants recognize a pathogen and halt the invasion by activating a defense mechanism, the disease is prevented and the pathogen behaves as avirulent. In these cases the interaction established is of the type incompatible otherwise is compatible. The defense response in plants is normally induced by signaling molecules called elicitors. The aim of this work was to evaluate the capacity of conidial extracts of an avirulent isolate of Colletotrichum fragariae to elicit in strawberry a defensive response against fungal disease. Experiments were conducted with plants of the cultivar Pájaro and with local isolates of C. fragariae and C. acutatum that induce incompatible and compatible interactions, respectively. The disease severe rate (DSR) was evaluated in petioles according to a scale ranging from 1 (no disease symptom) to 5 (maximum severity). Plants were firstly sprayed with conidial extracts of the avirulent C. fragariae strain, obtained by different procedures and after 72 hrs with the virulent C. acutatum. Results indicate that conidial extracts do not inhibit the growth of C. acutatum on PDA plates, but it does on strawberry plants. These outcomes suggest that extracts contain an active compound that induces a defensive response against a virulent fungal pathogen. The elicitor may be used as a novel strategy for the biocontrol of the antracnosis disease in strawberry.