Strategies for the Biocontrol of Fungal Diseases in Strawberry

DÍAZ RICCI JUAN CARLOS; TONELLO URSULA; CHALFOUN NADIA REGINA; SALAZAR SERGIO MIGUEL; VELLICCE GABRIEL; GRIGNOLA JOSEFINA; CASTAGNARO ATILIO PEDRO

S. M. de Tucumán, Argentina

Simposio; Simposio Internacional de Biotecnología (SIB). Aplicaciones en Alimentos, Salud y Medio Ambiente - II Simposio Argentino - Italiano de Bacterias Lácticas; 2004

CERELA

Plants have developed different strategies to resist the attack of pathogens.The defensive response depends on specific signals (elicitors) that may comes from the invader, the plant or produced in their interaction.Understnading in defense mechanisms pf a plant end the elicitors envolved constitute a major goal in plant biotechnology. In our group, we are conducing some research for characterizing the molecular events implicated in the defense response of strawberry toward fungal pathogens.Three posible strategies are proposed to tackle this problem, preserving environmentally safe criteria.We have implemented a transformation procedure that allowed us to obtain transgenic strawberries expressing heterologous defense genes.Results showed that transgenic lines expressing a chitinase gene (ch5B) coming from Phaseolus vulgaris, conferred plants resistance to Botrytis. In independent experiments, we have used conidial extracts of an avirulent strain of C fragariae that shows a typical incompatible interaction with the cultivar Pájaro, to elicit a defensive response against a virulent isolate of  C. acutatum, the etiologic agent of the anthracnose disease.Similar results were obtained when plants of the cv. Pájaro were pretreated with methanolic extracts obtained from healthy strawberry leaves. Research is been conducted to characterize the elicitors and the defense mechanism involved.