Genome-Wide Identification and Molecular Evolution of the Magnesium Transporter (MGT) Gene Family in Citrullus lanatus and Cucumis sativus

Abstract

Magnesium transporters (MGTs) play a prominent role in the absorption, transportation, and storage of magnesium in plant cells. In the present study, MGT gene family members were identified and characterized into two species of Cucurbitaceae, including Cucumis sativus and Citrullus lanatus. Totals of 20 and 19 MGT genes were recognized in Citrullus lanatus and Cucumis sativus, respectively. According to their physicochemical properties, the members of each sub-class of MGTs in the species of Cucurbitaceae showed the close relationship. Proteins from NIPA class were identified as hydrophilic proteins with high stability. Based on phylogenetic analysis, MGT family members were classified into three groups, and NIPAs showed more diversity. Moreover, duplication events were not identified between the MGT genes in C. lanatus and C. sativus. According to pocket analysis, residues such as L, V, S, I, and A were frequently observed in the binding sites of MGT proteins in both studied species. The prediction of post-translation modifications revealed that MSR2 proteins have higher phosphorylation potentials than other sub-classes of MGT in both studied plants. The expression profile of MGTs showed that MGTs are more expressed in root tissues. In addition, MGTs showed differential expression in response to abiotic/biotic stresses as well as hormone application and NIPAs were more induced in response to stimuli in watermelon. The results of this study, as the primary work of MGT gene family, can be used in programs related to Cucurbitaceae breeding.