Analysis of the potato calcium-dependent protein kinase family and characterization of StCDPK7, a member induced upon infection with Phytophthora infestans

FANTINO ELISA; SEGRETIN MARÍA EUGENIA; SANTIN FRANCO; MIRKIN FEDERRICO GABRIEL; ULLOA RITA MARÍA

PLANT CELL REPORTS

SPRINGER

Lugar: Berlin; Año: 2017

0721-7714

Abstract Calcium-dependent protein kinases (CDPKs)decode calcium (Ca2+) signals and activate different signalingpathways involved in hormone signaling, plantgrowth, development, and both abiotic and biotic stressresponses. In this study, we describe the potato CDPK/CRK multigene family; bioinformatic analysis allowed usto identify 20 new CDPK isoforms, three CDPK-relatedkinases (CRKs), and a CDPK-like kinase. Phylogeneticanalysis indicated that 26 StCDPKs can be classified intofour groups, whose members are predicted to undergodifferent acylation patterns and exhibited diverse expressionlevels in different tissues and in response to variousstimuli. With the aim of characterizing those members thatare particularly involved in plant?pathogen interaction, wefocused on StCDPK7. Tissue expression profile revealedthat StCDPK7 transcript levels are high in swollen stolons,roots, and mini tubers. Moreover, its expression is inducedupon Phytophthora infestans infection in systemic leaves.Transient expression assays showed that StCDPK7 displaysa cytosolic/nuclear localization in spite of having apredicted chloroplast transit peptide. The recombinantprotein, StCDPK7:6xHis, is an active Ca2+-dependentprotein kinase that can phosphorylate phenylalanineammonia lyase, an enzyme involved in plant defenseresponse. The analysis of the potato CDPK family providesthe first step towards the identification of CDPK isoformsinvolved in biotic stress. StCDPK7 emerges as a relevantplayer that could be manipulated to deploy disease resistancein potato crops.