A novel Zn transporter gene (ClZIP1) from turmeric (Curcuma longa L.) and expression analysis in presence of a Zn-solubilizing bacteria

Abstract

Zinc (Zn) deficiency is widespread in plants and molecular mechanism of uptake and transport within organelles is unclear. A novel Zn transporter gene was identified and characterized from turmeric (Curcuma longa L.) and expression analyzed in presence of zinc oxide (ZnO) and Bacillus safensis, a Zn-solubilizing bacteria (ZSB). Initially, eleven Zn transporters were mined from rhizome-specific transcriptome of turmeric and the one with highest transcript abundance designated as ClZIP1 was cloned and sequenced to give 1268-bp gene encoding 366 amino acids (ORF-1101 bp). In silico analysis and deduced protein designated ClZIP1 to Zn/Fe-regulated transporter (ZRT/IRT)-related protein (ZIP) family with 70.0% identity to Zn transporters from Musa acuminata. ClZIP1 possessed eight transmembrane (TM) domains with a variable region between TM-3 and TM-4 and conserved histidine-rich ZIP signature motif. A single 10-bp Zn deficiency-responsive element (ZDRE) was present in the promoter. ClZIP1 expression evaluated in in vitro plantlets in presence of Zn applied as ZnO (10–100 ppm), with/without ZSB indicated that it was higher in basal portion than leaf. This is the first report on ZIP gene from turmeric, which showed higher expression in the absence of ZSB and vice versa with maximum downregulation at 100 ppm Zn (88%)