Cloning, phylogenetic and expression analysis of soybean ferritin gene

To better understand soybean ferritin gene structure and its expression, a full length of 753bp cDNA fragment, which encoded a 250 amino acids peptide, was cloned by RT-PCR from a cultivar of Zhong Huang 13. Multiple sequence alignment and phylogenetic analysis were performed with ferritins from 6 species including Glycine max-, Arabidopsis thaliana, Oryza sativa, Physcomitrella patens, Brachypodium distachyon and Chlamydomonas. The results showed that gene lost occurred during the evolution of ferritin, and paralogs were widespread. Gene structure and phylogenetic analysis revealed that this soybean ferritin gene located on chromosome 18 with 8 exons and 7 introns and had high identity to other legume genes. Promoter analysis showed that a lot of stress responsive elements existed in this region including core promoter elements, indicates its possible function in soybean stress response. In silico expression revealed by Unigene database from NCBI did not give an obviously organ-specific expression pattern, but the expression level in green organ was higher than in other.