Cloning and expression analysis of a novel zinc transporter gene from Nasturtium officinale

ZIP (Zinc-regulated transporter, Iron-regulated transporter-like Protein, ZIP) plays an important role in uptake or transport Zn or Fe in plants. So studying ZIPs in plant can help to elucidate the molecular mechanism for Zn and Fe transportation. Herein, we have cloned a novel Zn transporter gene NoZIP3 from Nasturtium officinale root using rapid-amplification of cDNA ends (RACE) method, evaluated its function by functional complementation assay and determined its relative transcriptional level by quantitative real-time Reverse Transcription Polymerase Chain Reaction (qRT-PCR). The results showed that the full-length cDNA of NoZIP3 was 1029 bp, which encoded a polypeptide of 342 amino acids with a conserved domain of the typical ZIPs. NoZIP3 sequence shared a high similarity (57–89%) with that of other plant species. NoZIP3 could complement a mutant yeast deficient in Zn transportation; however, it could not complement that of Fe transportation. qRT-PCR revealed that the transcriptional level of NoZIP3 in roots was much higher than that in leaves under Zn deficiency, Fe deficiency or sufficient nutrition. These results suggested that NoZIP3 might be preferentially expressed in roots and had roles in Zn transportation, which could provide the foundation for further studying the characteristics and function of this gene.