Alteration of Iron Responsive Gene Expression in Arabidopsis Glutaredoxin S17 Loss of Function Plants With or Without Iron Stress

Authors

Ninghui Cheng
Han Yu
Xiaolan Rao
Sunghun Park
Erin L Connolly
Kendal D Hirschi
Paul A Nakata

Publication Date

6-2-2020

Journal

Plant Signaling & Behavior

DOI

10.1080/15592324.2020.1758455

PMID

32351167

PMCID

PMC8570760

PubMedCentral® Posted Date

4-30-2020

PubMedCentral® Full Text Version

Post-print

Published Open-Access

yes

Keywords

Arabidopsis, Arabidopsis Proteins, Glutaredoxins, Homeostasis, Iron, Plants, Genetically Modified, Transcription Factors, glutaredoxin, iron acquisition, redox, iron homeostasis

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.