Biochemical defense responses of potato cultivars to phosphites compounds.

LOBATO M C; FELDMAN M; MACHINADIARENA M; DALEO G; OLIVERI F; ANDREU A.B

Mar del Plata. Argentina

Congreso; SAIB 43th Annual Meeting; 2007

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

It has been reported that Phosphite compounds (Phi) can stimulate plant defense responses and that they are active against oomycetes. In the present work different biochemical responses in potato after Phi treatment were analyzed. Calcium and Potassium phosphites (CaPhi and KPhi) were applied to foliage under field conditions in cvs Spunta (SP), Kennebec (KN) and Shepody (SH). Phytopathological responses and activities of pathogenesis related proteins were measured in harvested tubers coming from Phi treated and non treated plants. Disease symptoms against Phytophthora infestans were reduced in KN and SP by KPhi and CaPhi. Fusarium solani colonization was reduced in SP and KN by CaPhi and KPhi, respectively. Peroxidase activity increased in SH by KPhi treatment, in SP after CaPhi treatment and a slight increase was observed in KN by both Phi. Serin protease inhibitor activity increased mainly in SP by CaPhi and KPhi and a minor response was observed in KN. Activity of glucanases also changed by Phi treatment showing a major increase by KPhi in all cultivars. The behaviour of these activities in infected tubers treated with the different Phi is being evaluated. Our results show that the response to Phi treatment depends on both the type of Phi and the cultivar analyzed. This is of interest to further utilizations of Phi in integrated crop management strategies.Financiado por:  CONICET, UNMDP, McCain Argentina SA, AGRO-EMCODI SA