Abstract: This work is to clone MYB21 gene and analyze its expression levels in different organs of kenaf for both cytoplasmic male sterility（CMS）and its maintainer,to construct over-expression vector and RNAi vector,and to lay the foundation for further study on the function of MYB21 gene in kenaf. The MYB21 gene was cloned using a homology method. The expression patterns of MYB21 in different organs for CMS and its maintainer were analyzed by quantitative real-time PCR. Using enzyme digestion-ligation method,the expression vector and RNAi vector were constructed. As results,there was no difference on gene sequence between CMS and its maintainer. The full cDNA sequence of MYB21 gene was 922 bp,including an 843 bp open reading frame. The full DNA sequence ofMYB21 gene was 1 108 bp,containing 3 exons and 2 introns（the NCBI GenBank accession number：KT898146）. MYB21 gene was predominantly expressed in anther,the expression level of MYB21 gene in anther between CMS and its maintainer was highly significant difference. Also the over-expression vector and RNAi vector were constructed successfully. In conclusion,the full-length sequence of MYB21 gene in kenaf is obtained,MYB21 gene is mainly expressed in anther of kenaf,and the over-expression vector PBI121-MYB21and RNAi vector pART27-PK-R1-F2 can be used for function study of MYB21 gene.

Key words: kenaf, cytoplasmic male sterility, MYB21 gene, quantitative real-time PCR, vector construction