Genome-wide computational assay of the Mg transporter (MGT) gene family in rice (Oryza sativa L.)

One of the critical biometals in the cells, possessing important functions in multiple biochemical pathways, is Magnesium (Mg). The proper Mg homeostasis is regulated by the Mg transporters (MGTs) in the cells. Despite the identification of these genes in various plant species, such as rice, there is no systematic and computational assay of all the existed MGT genes in the rice genome. Here, we identified 23 non-redundant MGTs across the genome of Oryza sativa that were further analyzed according to the protein characteristics, duplication and synteny, protein structures, expression, and co-expression networks. Based on the conserved motifs, the distinguished OsMGTs were classified into three main clades, including MRS, NIPA, and CorA. The α/β patterns in the protein structures were highly similar in the NIPA and MRS members, with the conserved structures in the Mg 2+ -binding and catalytic regions. The CorA clade-related proteins demonstrated the highest numbers of protein channels with Pro, Ser, Lys, Gly, and Tyr, as the critical binding residues. The expression analysis of OsMGT genes in various tissues showed that the MRS and NIPA groups MGTs may possess the critical functions during the rice development. Also, most of the up-regulated OsMGTs under stimuli exposure were from these clades of Mg transporters. Furthermore, 45 co-expressed genes were predicted for OsMGTs that were clustered into the three main groups involved in protein ubiquitination, amino acids/fatty acid degradations, and phenylpropanoid biosynthesis. Our in silico results can be informative for further evolutionary and functional genomics of the MGT genes in rice and other relatives.