ANALYSIS OF NDPK EXPRESSION IN POTATO PLANTS

BACHMANN SD; GRANDELLIS C; GIAMMARIA V; ULLOA RM.

Villa Carlos Paz, Córdoba

Congreso; XLIV Reunión Anual SAIB; 2008

SAIB

In plants, response mechanisms to biotic and abiotic stresses are regulated by different pathways that depend on early gene activation. Numerous kinases are involved in stress responses. Nucleoside diphosphate kinases (NDPKs) were long considered as house-keeping enzymes with a primary metabolic function, however, recent studies indicate that these enzymes might have a regulatory role in signal transduction events in plant responses to wounding, heat shock and pathogen infection. Three NDPK isoforms have been described in plants: NDPK1 in cytosol, NDPK2 in chloroplast stroma and NDPK3 in the chloroplast lumen and in the mitochondrial intermembrane space. Using primers designed on ESTs present on potato microarrays we amplified a 555 nt PCR fragment 89% homologous to NDPK3 from Spinacia oleracea. This isoform was expressed in buds, swelling stolons, sprouts and leaves of potato plants but not in dormant tubers. The primers amplified a 1694 nt PCR fragment when genomic DNA was used as template. This fragment was used as probe in a Southern blot assay. Primers that span an intronic region were designed to study the localization of this StNDPK gene in the potato genome. Semiquantitative RT-PCR assays are being performed to study NDPK3 expression in potato plants exposed to cold, high salt, defense signals (chitosan, PGA), hormones (GA , 3 ABA, AIA) and in PVY infected leaves