Antiphytopathogenic activity of a 316 Da preformed compound isolated from strawberry (Fragaria ananssa Duc) leaves

FILIPPONE, MAMANÍ DE MARCHESE, DÍAZ RICCI, FARÍAS, CASTAGNARO.

Tucumán, Argentina

Congreso; Jornadas Científicas de la Asociación de Biología de Tucumán (BIOCELL); 2000

Plants produces antimicrobial compounds that can be preformed or inducible. The aim of this work is to characterize a preformed antiphytopathogenic compound present in strawberry  (F.ananassa var. Chandler) leaves.The extraction was carried out from an homogenate, suspended in Tris-HCl 0.1M, EDTA, 10mM, PVP 1.5%, 2-mercaptoethanol 20mM, pH 7.5. The extract obtained was heated  (!00ºC, 10 min) filtered through a regenerates cellulose membrane (1.000 Da). The antibiotic activity was evaluated against the pathogenic bacterium Clavibacter michiganensis. The active fitered was chromatographied through an RP-FPLC (C1/C8 column, Pharmacia) with an acetonitrile/water gradient (0-100%) with 0.1% TFA. Two active ppeaks were obtained, one eluting at 0% acetonitrile that absorbed at 280nm and another at 100% with no absortion at 280nm. This last fraction was re-chromathographied with a 90100% acetonitrile gradient using the same column and a single active peak with absortion at 280 nm was obtained. The molecular weight of tjis compound was 316Da and was determined by MS. Determination of EC50 showed that this compound, called Fragarin, is more active against bacteria than fungi. These resultas suggest that Fragarin may be invloved in plant defense.