A cDNA named DlMADS18 was isolated from the young spikelets of the sweet bamboo, Dendrocalamus latiflorus by RACE. DNA sequence analysis showed that DlMADS18 was composed of full ORF and 3’UTR, but without 5’UTR. The cDNA contained 1039 nucleotides and encoded a putative protein of 249 amino acid residues. The gene displayed the structure of a typical plant MADS box gene, which consisted of an MADS domain, K domain, a short I region, and the C-terminal region. Phylogenetic analysis of plant MADS box genes based on amino acid se- quences revealed that DlMADS18 was grouped into the AGAMOUS-LIKE 6 (AGL6)-like subfamily. It was most likely homologous to the OsMADS6 of rice (Oryza sativa), with 88% sequence identity for the entire amino acid sequences. The DlMADS18 also showed relatively high amino acid sequence identity (59%) to AGL6 of Arabidopsis thaliana. To study the functions of DlMADS18, DlMADS18 cDNA clone driven by the CaMV 35S promoter was transformed into Arabidopsis plants. Transgenic plants of DlMADS18 exhibited the pheno- types of curled leaves, dwarfism, and early flowering with clustered terminal flowers. These results indicated that DlMADS18 may probably be involved in controlling the flowering time of D. latiflorus.
