INGEBI   02650
INSTITUTO DE INVESTIGACIONES EN INGENIERIA GENETICA Y BIOLOGIA MOLECULAR "DR. HECTOR N TORRES"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Deciphering the role of Calcium dependent protein kinases, CDPKs, in stress responses in potato plants
Autor/es:
SANTIN F; GROSSI CEM; SCIORRA M; ULLOA RM; FANTINO E; SANTIN F; SCIORRA M; GROSSI CEM; ULLOA RM; FANTINO E
Lugar:
Norwich
Reunión:
Conferencia; Plant Calcium Signalling Conference; 2017
Resumen:
Calcium-dependent protein kinases (CDPKs) decode calcium (Ca2+) signals andactivate different signaling pathways involved in hormone signaling, plant growth, development, and both abiotic and biotic stress responses. Data mining of the potato genome allowed us to identify twenty-six members of this family in Solanum tuberosum that can be classified into four groups (I to IV). Our group characterized three members of group II, StCDPK1/2/3, one member of group I, StCDPK7, and is now analyzing two members of group III, StCDPK22/24 that harbor only three EFhands in their calmodulin like domains. RT-qPCR analysis indicated that StCDPK1/2/3 and 7 are ubiquitously expressed in the plant tissues with different levels of expression; however, potato plants harboring the reporter GUS gene under the control of the CDPK promoters (proStCDPK1/2/3/7:GUS) show that each gene displays a specific spatio-temporal expression profile. In particular, histochemical analysis indicated that StCDPK1 is strongly associated to the vascular system [1].StCDPK1/2/3 are predicted to be myristoylated and palmitoylated and both StCDPK1and 2 are associated to the plasma membrane [2]. Regarding StCDPK7, transientexpression assays show that this kinase displays a cytosolic/nuclear localization in spite of having a predicted chloroplast transit peptide [3]. StCDPK1/2/3 and 7 encode active protein kinases that are able to phosphorylate syntide-2 and Histone in a Ca2+-dependent way; however, each one displays preference for a specific substrate in vitro. In the case of Group II isoforms, StCDPK1 was able to phosphorylate the auxin transporter StPIN4 [1], StCDPK2 strongly phosphorylates StABF transcription factor [4] and StCDPK3 phosphorylates StRSG and StABF [5]. On the other hand, StCDPK7 phosphorylates phenylalanine ammonia lyase isoforms, NtPAL1-4, and its expression was induced in systemic leaves upon Phytophthora infestans infection [2]. CDPK promoters share many regulatory elements related to biotic and abiotic stresses; but salt stress and dehydration-responsive elements are overrepresented in StCDPK2 promoter. With the aim of understanding the role of StCDPK2 and 7 in different stresses we are analyzing proStCDPK:GUS plants in response to high salt treatment and upon P. infestans infection. In addition, we obtained proS35:StCDPK2 plants and exposed them to salt treatments. Preliminar experiments performed in vitro indicate that proS35:StCDPK2 plants are more tolerant to salt than wild-type plants, showing increased root growth, biomass and chlorophyll content, and lower levels of H2O2.