Abstract:In order to reveal the function of homeobox (KNOX) gene in the stem development of Dendrocalamus latiflorus, a homologous gene of KNOX, named as DlKNOX, was cloned from the bamboo young stem using RT-PCR and RACE. The cDNA was 1511 bp in full length, including 5' UTR 196 bp, 3' UTR 238 bp and an ORF 1077 bp, which encoded a protein with 358 amino acids. The conserved domain analysis demonstrated that the protein contained KNOX1, KNOX2, ELK and Homeobox KN domains, which was in line with the characteristics of KNOX family, belonging to the class I protein. The bioinformatics analysis indicated that DlKNOX had the highest identities with OSH1 from rice for 86%. The expression analysis showed that DlKNOX expressed in knob with the highest level, next in stem, and the lowest in root. DlKNOX was expressed in Escherichia coli, and a recombinant protein about 82 kDa was obtained, which was consistent with the expected molecular weight of the recombinant protein composed of MBP (42.5 kDa) and DlKNOX (39.5 kDa). The optimum conditions for the expression of DlKNOX in E. coli were induced by 0.3 mmol L-1 IPTG for 2 h at 28℃. These lay the foundation for further research on the function of DlKNOX in stem development of D. latiflorus.
