Cloning and characterization of APETALA1 and APETALA2 genes from turkish endemic thermopsis turcica

The MADS-boxed APETALA1 (AP1) and two AP2-boxed APETALA2 (AP2) are A-function genes responsible for initiation and development of sepal and petals during the flowering of plants. In this research, Arabidopsis AP1 and AP2 homologous were isolated from young floral buds of multiple-carpellated T. turcica and their relative expressions were analyzed in reproductive tissues. Full length cDNAs of partially cloned genes were determined by using RACE (Rapid Amplification cDNA Ends) strategy. The full length cDNA of TtAP1 is 1074 bp and contains 714 bp protein coding sequence. It encodes a protein of 238 amino acids with functional MADS and K domains. Alignments and phylogenetics analysis indicated that TtAP1 was more similar to AP1 homologues determined for other legume species. The cDNA of TtAP2 encodes 545 amino acid from 1638 bp protein coding sequence.TtAP2 protein contains two well conserved AP2 domains, each 70 amino acids in length. The other parts of TtAP2 protein were more variable and less conserved. The relative expression analysis of TtAP1 and TtAP2 genes were determined in floral buds and floral organs (sepals, petals, stamens and carpels) of semi-opened flowers by using real-time quantitative PCR analysis. The highest transcript level of both genes were obviously determined in sepal tissue. The transcript level of TtAP1 was in order of sepals > young floral buds > petals > carpels > stamens. The order was sepals > carpel > young floral buds > petal > stamens for the TtAP2 transcripts.