CONICET | Buscador de Institutos y Recursos Humanos

Expression profiles of three calcium-dependent protein kinases during potato life cycle. Santin, Franco; Fantino, Elisa; Sciorra, Marcelo; Ulloa, RitaCalcium dependent protein kinases (CDPKs) have been reported to play roles in diverse biological processes in plants. In potato, CDPKs participate in tuberization as well as in stress responses. Here, we compare the expression profiles of three CDPKs. To determine the expression pattern of each isoform, qRT-PCR assays were conducted in different organs of potato plants. For the same purpose, potato transgenic lines harboring reporter gene beta-glucuronidase (GUS) under the control of each CDPK promoter were generated. A bioinformatic analysis of promoter sequences was carried out to identify cis-acting regulatory elements. In silico predictions revealed both, common and specific regulatory elements in the promoters. Histochemical GUS activity was analyzed in the different organs and tuberization stages. The expression patterns exhibited were distinct among isoforms. StCDPK1 is strongly associated to the vascular system in roots, stems, petioles, leaf veins, stolons and tubers. StCDPK2 expression was very strong in the leaf blade and veins but less intense in underground tissues, while StCDPK3 was expressed in leaves and axillary buds but was absent from petioles and stems. In roots, StCDPK2 and StCDPK3 expression patterns were similar being restricted to root tips and branching points while StCDPK1 expression was very intense all along the roots. The presence of common and specific regulatory elements could explain overlapping expression patterns in certain organs and exclusive in others. These results contribute to a better understanding the role of these versatile kinases in signaling cascades during potato life cycle. This work was supported by CONICET, UBA and ANPCyT.