Abstract Background Iron (Fe) is the most limiting micronutrient element for crop production in alkaline soils. A number of transcription factors involved in regulating Fe uptake from soil and transport in plants have been identified. Analysis of transcriptome data from <it>Oryza sativa </it>grown under limiting Fe conditions reveals that transcript abundances of several genes encoding transcription factors are altered by Fe availability. These transcription factors are putative regulators of Fe deficiency responses. Results Transcript abundance of one nuclear located basic helix-loop-helix family transcription factor, <it>OsIRO3</it>, is up-regulated from 25- to 90-fold under Fe deficiency in both root and shoot respectively. The expression of <it>OsIRO3 </it>is specifically induced by Fe deficiency, and not by other micronutrient deficiencies. Transgenic rice plants over-expressing <it>OsIRO3 </it>were hypersensitive to Fe deficiency, indicating that the Fe deficiency response was compromised. Furthermore, the Fe concentration in shoots of transgenic rice plants over-expressing <it>OsIRO3 </it>was less than that in wild-type plants. Analysis of the transcript abundances of genes normally induced by Fe deficiency in <it>OsIRO3 </it>over-expressing plants indicated their induction was markedly suppressed. Conclusion A novel Fe regulated bHLH transcription factor (OsIRO3) that plays an important role for Fe homeostasis in rice was identified. The inhibitory effect of <it>OsIRO3 </it>over-expression on Fe deficiency response gene expression combined with hypersensitivity of <it>OsIRO3 </it>over-expression lines to low Fe suggest that OsIRO3 is a negative regulator of the Fe deficiency response in rice.</p

Shou, Huixia

Wang, Fang

Wang, Lu

Whelan, James

Ying, Yinghui

Zheng,, Luqing

English

PubMed

Abstract
 
 Background
 Iron (Fe) is the most limiting micronutrient element for crop production in alkaline soils. A number of transcription factors involved in regulating Fe uptake from soil and transport in plants have been identified. Analysis of transcriptome data from Oryza sativa grown under limiting Fe conditions reveals that transcript abundances of several genes encoding transcription factors are altered by Fe availability. These transcription factors are putative regulators of Fe deficiency responses.
 
 
 Results
 Transcript abundance of one nuclear located basic helix-loop-helix family transcription factor, OsIRO3, is up-regulated from 25- to 90-fold under Fe deficiency in both root and shoot respectively. The expression of OsIRO3 is specifically induced by Fe deficiency, and not by other micronutrient deficiencies. Transgenic rice plants over-expressing OsIRO3 were hypersensitive to Fe deficiency, indicating that the Fe deficiency response was compromised. Furthermore, the Fe concentration in shoots of transgenic rice plants over-expressing OsIRO3 was less than that in wild-type plants. Analysis of the transcript abundances of genes normally induced by Fe deficiency in OsIRO3 over-expressing plants indicated their induction was markedly suppressed.
 
 
 Conclusion
 A novel Fe regulated bHLH transcription factor (OsIRO3) that plays an important role for Fe homeostasis in rice was identified. The inhibitory effect of OsIRO3 over-expression on Fe deficiency response gene expression combined with hypersensitivity of OsIRO3 over-expression lines to low Fe suggest that OsIRO3 is a negative regulator of the Fe deficiency response in rice.
 </jats:sec

Luqing Zheng,

Yinghui Ying

Lu Wang

Fang Wang

James Whelan

Huixia Shou

Crossref

BMC Plant Biology

Identification of a novel iron regulated basic helix-loop-helix protein involved in Fe homeostasis in Oryza sativa

Springer - Publisher Connector

Identification of a novel iron regulated basic helix-loop-helix protein involved in Fe homeostasis in 

Abstract Background Iron (Fe) is the most limiting micronutrient element for crop production in alkaline soils. A number of transcription factors involved in regulating Fe uptake from soil and transport in plants have been identified. Analysis of transcriptome data from Oryza sativa grown under limiting Fe conditions reveals that transcript abundances of several genes encoding transcription factors are altered by Fe availability. These transcription factors are putative regulators of Fe deficiency responses. Results Transcript abundance of one nuclear located basic helix-loop-helix family transcription factor, OsIRO3, is up-regulated from 25- to 90-fold under Fe deficiency in both root and shoot respectively. The expression of OsIRO3 is specifically induced by Fe deficiency, and not by other micronutrient deficiencies. Transgenic rice plants over-expressing OsIRO3 were hypersensitive to Fe deficiency, indicating that the Fe deficiency response was compromised. Furthermore, the Fe concentration in shoots of transgenic rice plants over-expressing OsIRO3 was less than that in wild-type plants. Analysis of the transcript abundances of genes normally induced by Fe deficiency in OsIRO3 over-expressing plants indicated their induction was markedly suppressed. Conclusion A novel Fe regulated bHLH transcription factor (OsIRO3) that plays an important role for Fe homeostasis in rice was identified. The inhibitory effect of OsIRO3 over-expression on Fe deficiency response gene expression combined with hypersensitivity of OsIRO3 over-expression lines to low Fe suggest that OsIRO3 is a negative regulator of the Fe deficiency response in rice.</p

Zheng, Luqing

Ying Yinghui

Wang Lu

Wang Fang

Whelan James

Shou Huixia

Directory of Open Access Journals

Identification of a novel iron regulated basic helix-loop-helix protein involved in Fe homeostasis in <it>Oryza sativa</it>

al: Genome-wide analysis of basic/helix-loop-helix transcription factor family in rice and Arabidopsis. Plant Physiol

al: Physiological and Transcriptome Analysis of Iron and Phosphorus Interaction in Rice Seedlings. Plant Physiol

An Arabidopsis basic helix-loop-helix leucine zipper protein modulates metal homeostasis and auxin conjugate responsiveness. Genetics

Biochemistry and Molecular Biology of Plants.

Buckhout TJ: Response of Arabidopsis to iron deficiency stress as revealed by microarray analysis. Plant Physiol

Cloning and characterization of the OsNramp family from Oryza sativa, a new family of membrane proteins possibly implicated in the transport of metal ions. Plant Molecular Biology

Connolly EL: Time to pump iron: iron-deficiency-signaling mechanisms of higher plants.

Czernic P: Increased sensitivity to iron deficiency in Arabidopsis thaliana overaccumulating nicotianamine.

Different strategies in higher plants in mobilization and uptake of iron.

Dissecting iron deficiency-induced proton extrusion in Arabidopsis roots. New Phytologist

Distribution and characterization of over 1000 T-DNA tags in rice genome.

EL: Maize yellow stripe1 encodes a membrane protein directly involved in Fe(III) uptake. Nature

et al: Mutation in nicotianamine aminotransferase stimulated the Fe(II) acquisition system and led to iron accumulation in rice. Plant Physiol

et al: Nicotianamine, a Novel Enhancer of Rice Iron Bioavailability to Humans. PLoS ONE

Guerinot ML: Mining iron: iron uptake and transport in plants. FEBS letters

Hakoshima T: Crystal structure of PHO4 bHLH domain-DNA complex: flanking base recognition.

Iron transport and signaling in plants. Annu Rev Plant Biol

Iron: nutritious, noxious, and not readily available. Plant Physiol

Iwashita T: A specific transporter for iron(III)-phytosiderophore in barley roots.

Ling HQ: FIT interacts with AtbHLH38 and AtbHLH39 in regulating iron uptake gene expression for iron homeostasis in Arabidopsis. Cell Res

MEGA4: Molecular Evolutionary Genetics Analysis (MEGA) software version 4.0. Mol Biol Evol

ML: A ferric-chelate reductase for iron uptake from soils. Nature

ML: A novel iron-regulated metal transporter from plants identified by functional expression in yeast.

ML: The essential basic helix-loop-helix protein FIT1 is required for the iron deficiency response. Plant Cell

Nishizawa N: A novel NAC transcription factor, IDEF2, that recognizes the iron deficiency-responsive element 2 regulates the genes involved in iron homeostasis in plants.

Nishizawa NK: Identification of novel cis-acting elements, IDE1 and IDE2, of the barley IDS2 gene promoter conferring iron-deficiency-inducible, root-specific expression in heterogeneous tobacco plants.

Nishizawa NK: Isolation and characterization of IRO2, a novel ironregulated bHLH transcription factor in graminaceous plants.

Nishizawa NK: Rice OsYSL15 Is an Ironregulated Iron(III)-Deoxymugineic Acid Transporter Expressed in the Roots and Is Essential for Iron Uptake in Early Growth of the Seedlings.

Nishizawa NK: The rice bHLH protein OsIRO2 is an essential regulator of the genes involved in Fe uptake under Fe-deficient conditions.

Nishizawa NK: The transcription factor IDEF1 regulates the response to and tolerance of iron deficiency in plants. Proc Natl Acad Sci USA

Nishizawa NK: Three rice nicotianamine synthase genes, OsNAS1, OsNAS2, and OsNAS3 are expressed in cells involved in long-distance transport of iron and differentially regulated by iron.

Origin and Diversification of Basic-Helix-Loop-Helix Proteins in Plants. Mol Biol Evol

Pabo C: Crystal structure of MyoD bHLH domain-DNA complex: perspectives on DNA recognition and implications for transcriptional activation. Cell

SY: A rice transcription factor OsbHLH1 is involved in cold stress response. Theor Appl Genet

The tomato fer gene encoding a bHLH protein controls iron-uptake responses in roots.

file:///data/core-remote/dit/data/Springer-OA/pdf/d00/aHR0cDovL2xpbmsuc3ByaW5nZXIuY29tLzEwLjExODYvMTQ3MS0yMjI5LTEwLTE2Ni5wZGY=.pdf

Identification of a novel iron regulated basic helix-loop-helix protein involved in Fe homeostasis in Oryza sativa

Abstract

Similar works

Full text

Available Versions

Crossref

Springer - Publisher Connector

Directory of Open Access Journals