Abstract:Casein kinase (CK), a ubiquitous Ser/Thr protein kinase, plays an important role in the whole physiological process and signal transduction pathway of plants through regulating activity and stability of target protein. The CK gene family in Jatropha curcas was identified from J. curcas genome based on the BLAST method. The results showed that a total of seven CK1s, five PS-CK1s, three CK2-αs, and two CK2-βs were identified from J. curcas genome, and the four subfamily members owned family-specificity in amino acid length, isoelectrical point, and exon number. Domain and motif analysis revealed that all of CK1 contain N-terminal conserved kinase domain, and the kinase activation loop (A-loop), ATP-binding core motif, and nuclear localization signal peptide (NLS) were identified in its interior. A plant-specific casein kinse 1-5 gene, named JcPS-CK1-5, was cloned. qRT-PCR analysis showed that JcPS-CK1-5 gene was a low temperature-induced gene in both leaves and roots, and might be involved in cold resistance of J. curcas. A prokaryotic expression vector pET-32a-JcPS-CK1-5 was constructed and transformed into Escherichia coli BL21(DE3). A band of 81.6 kD was obtained, which was consistent with the expected weight. Therefore, these would provide a reference for studying the functional identification of CK gene and the stress signal transduction mechanism in J. curcas.