Potato transgenic lines harboring StCDPK1 promoter-GUS fusion reveal spatio-temporal gene expression profile during tuberization

SANTIN, FRANCO; FANTINO, ELISA; GÓMEZ-POVIÑA, JUAN CRUZ; ULLOA, RITA M

Mar del Plata

Congreso; XV Congreso Latinoamericano XXX Reunión Argentina de Fisiología Vegetal; 2014

Sociedad Argentina de Fisiología Vegetal

Tuberization is a complex developmental process that results in the differentiation of a specialized shoot (stolon), into a storage organ called tuber. Calcium-dependent protein kinases (CDPKs) are calcium sensors that play important roles regulating plant growth and development. Our previous studies show that Ca2+-dependent protein kinase StCDPK1 is transiently expressed in tuberizing stolons suggesting its possible involvement in potato tuberization. Here, we show the spatio-temporal expression profile of StCDPK1 in different tuberization stages by histochemical localization of β-glucuronidase (GUS) activity in potato transgenic lines harboring StCDPK1 promoter-GUS fusion. Furthermore, GUS expression was detected in roots. In accordance with these results, the in silico analysis of StCDPK1 promoter predicted cis-acting elements found in promoters of storage proteins and root-specific genes. We also demonstrate that the recombinant enzyme is capable of autophosphorylation at multiple residues as shown by 2D-PAGE analysis. Finaly, we confirmed StCDPK1 phosphorylates the potato homolog to the Arabidopsis drought induced transcription factor AtDi19.