Cloning and characterization of TOM7-like gene in wheat.

The cDNA encoding TOM7 (translocase of outer mitochondrial membrane subunit 7) like protein in wheat was cloned through RT-PCR, and its genomic DNA fragment was subsequently cloned. This gene was tentatively designated as TaTOM7. It has no intron in the coding region and its product possesses one hydrophobic trans-membrane domain in the middle, and one hydrophilic domain in the N-terminal and C-terminal domain, respectively. The amino acid composition in the trans-membrane domain of the TaTOM7 subunit is highly conserved among plants, animals and fungi. According to the phylogenetic tree, TOM7-like proteins from different species can be classified into three groups, representing plants, animals and fungi respectively. TaTOM7 is a single- or oligo-copy gene in the wheat genome, displaying different expression levels between Ms2 near-isogenic lines in some tissues, suggesting a role of Ms2 in its expression. TaTOM7 was mapped to chromosome group three of wheat.