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

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

PLANT CELL REPORTS

SPRINGER

Lugar: Berlin; Año: 2017

0721-7714

Abstract Calcium-dependent protein kinases (CDPKs) decode calcium (Ca2+) signals and activate different signaling pathways involved in hormone signaling, plant growth, development, and both abiotic and biotic stress responses. In this study, we describe the potato CDPK/CRK multigene family; bioinformatic analysis allowed us to identify twenty new CDPK isoforms, three CDPK-related kinases (CRKs) and a CDPK-like kinase. Phylogenetic analysis indicated that twenty-six StCDPKs can be classified into four groups, whose members are predicted to undergo different acylation patterns and exhibited diverse expression levels in different tissues and in response to various stimuli. With the aim of characterizing those members that are particularly involved in plant-pathogen interaction, we focused on StCDPK7. Tissue expression profile revealed that StCDPK7 transcript levels are high in swollen stolons, roots, and mini tubers. Moreover, its expression is induced upon Phytophthora infestans infection in systemic leaves. Transient expression assays showed that StCDPK7 displays a cytosolic/nuclear localization in spite of having a predicted chloroplast transit peptide. The recombinant protein, StCDPK7:6xHis, is an active Ca2+-dependent protein kinase that can phosphorylate phenylalanine ammonia lyase, an enzyme involved in plant defense response. The analysis of the potato CDPK family provides the first step towards the identification of CDPK isoforms involved in biotic stress. StCDPK7 emerges as a relevant player that could be manipulated in order to deploy disease resistance in potato crops.