Functional analysis of RcMsc2 gene in castor (Ricinus communis)

Abstract

G2/mitotic-specific cyclin-2 (Msc2), as a key regulatory protein in response to stress in higher plants, is involved in multiple responses to stresses. In order to explore the function of RcMsc2 gene which was successfully cloned from castor leaf tissue, the structure and potential function of RcMsc2 protein were analyzed by bioinformatics, and the expression characteristics of RcMsc2 gene in tissue and abiotic stress were analyzed by qRT-PCR. The results were as follows: (1) RcMsc2 gene was located in the long arm of Chromosome 5 in castor, and its CDS region was 1 299 bp, encoding 432 amino acids. (2) RcMsc2 protein has the characteristic domain of cyclin family, which was an unstable acidic hydrophilic protein without transmembrane domain and signal peptide, and its relative molecular weight was 49.38 kD. (3) The secondary and tertiary structures of RcMsc2 protein were mainly α-helix and random coil. (4) RcMsc2 protein had the highest sequence homology with CYCB2 protein of Jatropha curcas and Hevea brasiliensis, and was clustered into Group Ⅱ. (5) 35S-RcMsc2-GFP fusion protein was localized to the nucleus. (6) RcMsc2 gene was expressed in all tissues of castor, and mainly played a role in roots and stems; abiotic stress analysis showed that RcMsc2 gene could be induced by abscisic acid (ABA), salt, drought and low temperature treatment, and the response of RcMsc2 gene to low temperature stress was the most sensitive. In summary, this study comprehensively analyzed the structural characteristics, phylogenetic evolution and expression patterns of RcMsc2 gene, and provides a theoretical reference for revealing the function of RcMsc2 gene in castor growth and development and response to cold stress.

Keywords

• castor
• rcmsc2
• gene cloning
• expression characteristics
• cold stress