Cloning and Expression Analysis of CIPK Gene in Sugarcane

CIPK(calcineurin B-like-interacting protein kinase) is a plant specific class of serine / threonine protein kinases, which plays an important role in plant response to stress, especially relates with the signal transduction for biotic stresses(drought, high salt, ABA). According to the primers designed on the conserved domain of CIPK15 gene from Zea mays, a full-length c DNA sequence of serine/threonine kinase gene termed as Sc CIPK was cloned by RT-PCR method from sugarcane(Saccharum Complex). The sequence analysis showed that Sc CIPK had a length of 1782 bp containing the open reading frame(ORF, 91–1631 bp), which encoded 513 amino acids residues with two conserved domains(Kc-like superfamily and AMPKA-C-like superfamily). The characters predicted based on the bioinformatics analysis revealed that the Sc CIPK gene of sugarcane was a soluble acidic protein, which has two conserved functional domains with the main function for central_intermediary_metabolism, and its protein was located in endoplasmic reticulum(membrane). The mainly secondary structure element was α-helix. Real-time quantitative PCR(RT-q PCR) analysis revealed that the expression of Sc CIPK was higher in bud than in other tissues, meanwhile the inducible expression level of Sc CIPK was most significantly up-regulated under the ABA stress, 5.3 times higher than that of control, which suggested that Sc CIPK most probably involves in sugarcane resistance to drought and osmotic stresses. The results in this study could provide a basis of cloning and functional identification of other members of Sc CIPK in sugarcane and promote the use of Sc CIPK gene in sugarcane genetic engineering.