Expression Analysis of Two CIPK genes under Abiotic Stress in Foxtail Millet

Abstract

CIPK (CBL interacting protein kinase) is a type of serine or threonine protein kinases, which plays an important role in response to stress. In this study, we identified two CIPK genes designated as SiCIPK6 and SiCIPK16 from foxtail millet (Setaria italica) genome using bioinformatics methods. The sequence analysis showed that SiCIPK6 has a length of 1994 bp in the genome, encoding 513 amino acids residues, and SiCIPK16 is 1885 bp, encoding 473 amino acids residues. These two genes have no al- ternative splicing and intron. The characters predicted based on the bioinformatics analysis revealed that the protein sequences and structure of the two SiCIPK genes were very conservative just like CIPK genes in other species. Real-time PCR analysis discov- ered that the expression of SiCIPK6 and SiCIPK16 was up-regulated by ABA, cold, heat, drought and salt stress, respectively. The expression was strongly induced by ABA, drought and salt treatments for SiCIPK6, and by cold, drought and heat treatments for SiCIPK16. The semi-quantitative PCR analysis showed that SiCIPK6 and SiCIPK16 were expressed at the jointing, booting and filling stages, and induced by drought stress in the corresponding growth period. Foxtail millet CIPK genes reported in this study would enrich CIPK members in plant kingdom and provides important information for further elucidating the function and mechanisms of the CBL/CIPK network system responsive to stresses in foxtail millet.