Alteration of iron responsive gene expression in Arabidopsis glutaredoxin S17 loss of function plants with or without iron stress

Plant Signal Behav. 2020 Jun 2;15(6):1758455. doi: 10.1080/15592324.2020.1758455. Epub 2020 Apr 30.

Abstract

Iron (Fe) is a mineral nutrient and a metal cofactor essential for plants. Iron limitation can have detrimental effects on plant growth and development, while excess iron inside plant cells leads to oxidative damage. As a result, plants have evolved complex regulatory networks to respond to fluctuations in cellular iron concentrations. The mechanisms that regulate these responses however, are not fully understood. Heterologous expression of an Arabidopsis thaliana monothiol glutaredoxin S17 (GRXS17) suppresses the over-accumulation of iron in the Saccharomyces cerevisiae Grx3/Grx4 mutant and disruption of GRXS17 causes plant sensitivity to exogenous oxidants and iron deficiency stress. GRXS17 may act as an important regulator in the plant's ability to respond to iron deficiency stress and maintain redox homeostasis. Here, we extend this investigation by analyzing iron-responsive gene expression of the Fer-like iron deficiency-induced transcription factor (FIT) network (FIT, IRT1, FRO1, and FRO2) and the bHLH transcription factor POPEYE (PYE) network (PYE, ZIF1, FRO3, NAS4, and BTS) in GRXS17 KO plants and wildtype controls grown under iron sufficiency and deficiency conditions. Our findings suggest that GRXS17 is required for tolerance to iron deficiency, and plays a negative regulatory role under conditions of iron sufficiency.

Keywords: glutaredoxin; iron acquisition; iron homeostasis; redox.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / metabolism
  • Glutaredoxins / metabolism*
  • Homeostasis
  • Iron / metabolism*
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Arabidopsis Proteins
  • Glutaredoxins
  • Transcription Factors
  • Iron

Grant support

This work was supported by the United States Department of Agriculture, Agricultural Research Service through Cooperative Agreement Number 58-6250-0-008. The contents of this publication do not necessarily reflect the views or policies of the US Department of Agriculture, nor does mention of trade names, commercial products, or organizations imply endorsement by the US Government. Erin L. Connolly was supported by NSF IOS 1456881.