Computational characterization and expression profile of MTP1 gene associated with zinc homeostasis across dicot plant species

Abstract

This study characterizes different MTP1 (metal tolerance protein)/ZAT (zinc transporter) homologs involved in zinc (Zn) homeostasis in plants. BLAST analysis of AtMTP1 protein against 15 plant species showed 21 MTP1 homologs. These MTP1 protein homologs generally contain ~400 residues, six transmembrane helices and cation transmembrane transporter activity (GO:0008324), which can be utilized in predicting Zn uptake and tolerance mechanisms. These MTP1 genes having 1 exon are located on chromosomes 2, 7, and 14. Motifs contain conserved sequences of 41–50 residues belonging to the cation efflux family, which may help target binding sites and transcription factors. Further, AtMTP1 shows close similarities with Glycine max and Medicago trunculata. Interactome analysis suggests the association of AtMTP1 with cadmium/zinc-transporting ATPase and ZIP metal ion transporter. The AtMTP1 network is predominantly connected to cadmium/zinc-transporting ATPase (heavy metal ATPase 2, HMA2; heavy metal ATPase 3, HMA3; heavy metal ATPase 4, HMA4), cation efflux protein (MTP11), and metal tolerance protein C3 (AT4G58060). The Genevestigator predicts the high expression potential of AtMTP1 in the apical root during senescence, seedling, and bolting stages in an association with 11 co-expressed genes, mainly linked to estradiol toxicity and heat stress. Besides, AtMTP1 protein homologs possess conserved N-glyco motifs and physicochemical properties. The similarity and interactions of AtMTP1 gene with other genes suggest that Zn homeostasis in plants is associated with the regulation of different genes. These findings may advance our understanding to further develop plants capable of maintaining Zn homeostasis under adverse conditions.