Cloning and characterization of APETALA3 and PISTILLATA gene homolog in multi-carpellated Thermopsis turcica a turkish endemic

Arabidopsis APETALA3 (AP3) and PISTILATA (PI) genes are B-class MADS-box genes and responsible for the development of petals and stamens during plant flowering. In present study, isolation and characterization of AP3 and PI gene homolog were aimed from the endemic Thermopsis turcica Tan, Vural and Küçüködük, an unusual legume species with multi-carpellated pod production. The isolation of these target genes were achieved from young floral buds by using molecular tools including routine PCR, RACE analysis, sequencing and bioinformatics tools. Transcript levels of TtAP3 and TtPI genes in the young floral buds and semi-opened floral tissues (sepals, petals, stamens and carpels) of T turcica have been analyzed by the technique of real time semi-quantitative polymerase chance reaction (RT-qPCR). It was determined that the full-length cDNAs of TtAP3 and TtPI genes have the open reading frames with 681 (codes for 226 aa) and 546 nt (codes for 181 aa), respectively. Both genes encodes for a MIKC-type MADS domain protein. In comparison to the protein homolog determined for other plants such as Arabidopsis, the deduced TtAP3 protein has the conserved PI and euAP3 motifs at its C terminal, but the deduced TtPI has not got the conserved PI motif at its C-terminal. The highest TtPI transcript level was determined in the petal and stamen tissues of semi-opened flower by using RT-qPCR technique. However, the level of TtAP3 transcripts was higher in the floral buds, sepals and carpels than that of petals and stamens, where literately expected to be higher. iv The structural and functional analyses indicated that the isolated T. turcica TtAP3 and TtPI genes are the homolog genes of Arabidopsis AP3 and PI genes, respectively. The detailed expression profile of TtAP3 gene via differential display or in situ-hybridization analysis could be a further research topic.