Characterization of a Novel Iron Deficiency Regulated Glutathione Transporter (IGT) in rice

Abstract

Glutathione (GSH) is involved in many aspects of plant growth and development including redox control, storage and transport of reduced sulfur, and response to biotic and abiotic stresses. The transport and compartmentalization of GSH is essential to perform all these functions. We have cloned an Iron (Fe) deficiency regulated GSH transporter (IGT) from rice. IGT is a putative member of oligopeptide transporters (OPT) family, and was identified through microarray analysis as its expression was highly upregulated in response to Fe-deficiency. IGT showed high homology i.e. 82% homology to BjGT1 and 80% homology to AtOPT3. Electrophysiological measurements using Xenopus leavis oocytes showed that IGT is a functional GSH transporter. Northern blot analysis and IGT promoter-GUS analysis confirmed that its expression is induced in response to Fe-deficiency in root as well as in shoot tissue. These results suggested that IGT plays a critical role in mitigating Fe-deficiency induced stress in rice.