Genome-wide identification and expression analysis of the potato ZIP gene family under Zn-deficiency

Abstract

Zinc deficiency is a worldwide problem for crops including potato (Solanum tuberosum L.), the fourth most important crop worldwide. The zinc/iron-regulated transporter-like protein (ZIP) transporter family is thought to play key roles in Zn uptake and transport. However, little is known about the potato ZIP family. In this study, 12 genes encoding members of the ZIP family were identified in the potato genome. The 12 StZIP genes were predicted to encode proteins of 220 - 407 amino acids harboring 5 - 9 putative transmembrane domains (TMDs), and 11 of these proteins had a variable region rich in histidine residues between TMDIII and TMDIV. A phylogenetic analysis divided the StZIPs into four groups on the basis of gene structure and conserved motifs. Furthermore, the StZIP expression profiles were determined under Zn-deficiency in both high and low Zn-content genotypes. Four differentially expressed genes, StZIP6, -9, -11, and -12, were identified in tubers of the two genotypes under Zn-deficiency, and StZIP11 and StZIP12 may have a more prominent function in Zn uptake and accumulation in potato tubers owing to their higher expressions. Thus, the results provide useful information for further studying the functions of StZIP genes.