Molecular Cloning and Analysis of Two Flowering Related Genes from Apple (Malus × domestica)

Apple (Malus × domestica Borkh.) is the fourth fruit in importance and Iran ranks fifth in apple production in the world. Longevity of juvenility in apple extends breeding cycles and makes its breeding a tough job. To alleviate this barrier via genetic engineering, the genes involved in flowering and floral development of apple and their function must be identified and characterized. Most of these genes fall in a class of transcription factors named MADS-box genes. In the present research, we cloned and analysed the sequences and features of two of these genes, MdMADS1 and MdMADS3, from apple ‘Golden Delicious’ for a deeper functional analysis in the near future. They were found to be homologs of SEP genes belonging to the class E genes involved in flower development and lied in the AGL2 clade of MADS-box genes in the phylogenetic tree made for apple and Arabidopsis MADS-box proteins. In silico studies exemplified that both genes had eight exons and seven introns with a long first intron of about 4 Kb and 3 Kb for MdMADS1 and MdMADS3, respectively. The results showed that the structure of both genes has noticeably differed from other SEP-like genes in evolution.