In vitro cultures of Vitis vinifera L. cv. Chardonnay synthesize the phytoalexin nerolidol upon infection by Phaeoacremonium parasiticum

GEORGINA ESCORIAZA, PEDRO SANSBERRO, SANDRA GARCÍA LAMPASONA, MARTA GATICA, RUBÉN BOTTINI, PATRICIA PICCOLI

PHYTOPATHOLOGIA MEDITERRANEA

MEDITERRANEAN PHYTOPATHOLOGICAL UNION

Lugar: Firenze- Italia; Año: 2013 vol. 52 p. 289 - 297

0031-9465

This study investigated terpene synthase activity (TPS) and terpene antifungal metabolites in calli and cell suspension cultures of Vitis vinifera cv. Chardonnay infected with Phaecremonium parasiticum, one of the fungi associated with the grapevine diseases known as ?hoja de malvón? and ?young vine decline?. The highest TPS activity, assessed as tritiated farnesyl pyrophosphate ([1-3H]-FPP) transformed into hexane-soluble radioactive products, was observed in both inoculated calli and cell suspension cultures. When tested in inoculated cell suspension cultures TPS activity showed maximal 8 h after [1-3H]-FPP application and then declined. Grape calli and cell suspension cultures inoculated or not with Pm. parasiticum produced α-pinene, nerolidol and squalene respectively. As fungal amount raised the relative concentration of α-pinene and nerolidol increased respect to squalene in calli. The TPS activity and nerolidol and α-pinene accumulation was correlated with the increment of inoculated fungus. Of the mentioned metabolites mainly squalene was identified from extracts of fungal cultures. The results suggest that the response of grapevine tissues to Pm. parasiticum is dependent on the pathogen concentration, and characterized by increasing terpene synthase activity through de novo synthesis