Iron deficiency regulated OsOPT7 is essential for iron homeostasis in rice

Plant Mol Biol. 2015 May;88(1-2):165-76. doi: 10.1007/s11103-015-0315-0. Epub 2015 Apr 18.

Abstract

The molecular mechanism of iron (Fe) uptake and transport in plants are well-characterized; however, many components of Fe homeostasis remain unclear. We cloned iron-deficiency-regulated oligopeptide transporter 7 (OsOPT7) from rice. OsOPT7 localized to the plasma membrane and did not transport Fe(III)-DMA or Fe(II)-NA and GSH in Xenopus laevis oocytes. Furthermore OsOPT7 did not complement the growth of yeast fet3fet4 mutant. OsOPT7 was specifically upregulated in response to Fe-deficiency. Promoter GUS analysis revealed that OsOPT7 expresses in root tips, root vascular tissue and shoots as well as during seed development. Microarray analysis of OsOPT7 knockout 1 (opt7-1) revealed the upregulation of Fe-deficiency-responsive genes in plants grown under Fe-sufficient conditions, despite the high Fe and ferritin concentrations in shoot tissue indicating that Fe may not be available for physiological functions. Plants overexpressing OsOPT7 do not exhibit any phenotype and do not accumulate more Fe compared to wild type plants. These results indicate that OsOPT7 may be involved in Fe transport in rice.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Assay
  • Ferritins / metabolism
  • Gene Expression Regulation, Plant
  • Gene Knockout Techniques
  • Glucuronidase / metabolism
  • Glutathione / metabolism
  • Homeostasis*
  • Iron / metabolism
  • Iron Deficiencies*
  • Micronutrients / metabolism
  • Mutation / genetics
  • Oligonucleotide Array Sequence Analysis
  • Oocytes / metabolism
  • Oryza / genetics
  • Oryza / metabolism*
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plants, Genetically Modified
  • Promoter Regions, Genetic / genetics
  • Protein Transport
  • Stress, Physiological / genetics
  • Subcellular Fractions / metabolism
  • Xenopus laevis

Substances

  • Micronutrients
  • Plant Proteins
  • Ferritins
  • Iron
  • Glucuronidase
  • Glutathione