The expression of iron homeostasis-related genes during rice germination

Nozoye, Tomoko; Inoue, Haruhiko; Takahashi, Michiko; Ishimaru, Yasuhiro; Nakanishi, Hiromi; Mori, Satoshi; Nishizawa, Naoko K.

doi:10.1007/s11103-007-9132-4

Cited by 59 publications

(74 citation statements)

References 60 publications

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“…OsVP1, AK109920, and AK101356 were also constitutively expressed in roots and leaves, but AK072874 expression was not detected in these organs (data not shown). These results are in accordance with our previous microarray experiment using rice 22k array slides (10,11,27), which also indicated that IDEF1, in addition to OsVP1, is clearly expressed in germinating seeds (data not shown). Because of the substantial expression of IDEF1 in vegetative organs, in contrast to little expression of AK072874, which constitutes the subgroup of IDE1/Sph/RY-binding factors with IDEF1 ( Fig.…”

Section: Resultssupporting

confidence: 93%

The transcription factor IDEF1 regulates the response to and tolerance of iron deficiency in plants

Kobayashi

Ogo²,

Itai³

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

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Iron is essential for most living organisms and is often the major limiting nutrient for normal growth. Plants induce iron utilization systems under conditions of low iron availability, but the molecular mechanisms of gene regulation under iron deficiency remain largely unknown. We identified the rice transcription factor IDEF1, which specifically binds the iron deficiency-responsive cis-acting element IDE1. IDEF1 belongs to an uncharacterized branch of the plant-specific transcription factor family ABI3/VP1 and exhibits the sequence recognition property of efficiently binding to the CATGC sequence within IDE1. IDEF1 transcripts are constitutively present in rice roots and leaves. Transgenic tobacco plants expressing IDEF1 under the control of the constitutive cauliflower mosaic virus 35S promoter transactivate IDE1-mediated expression only in iron-deficient roots. Transgenic rice plants expressing an introduced IDEF1 exhibit substantial tolerance to iron deficiency in both hydroponic culture and calcareous soil. IDEF1 overexpression leads to the enhanced expression of the iron deficiency-induced transcription factor gene OsIRO2, suggesting the presence of a sequential gene regulatory network. These findings reveal cis element/trans factor interactions that are functionally linked to the iron deficiency response. Manipulation of IDEF1 also provides another approach for producing crops tolerant of iron deficiency to enhance food and biomass production in calcareous soils.ABI3/VP1 ͉ iron deficiency-responsive elements ͉ mugineic acid family phytosiderophores ͉ transgenic rice M ost living organisms require iron for growth and reproduction, and the iron absorbed by plants constitutes a major iron source for animals and humans. Although abundant in mineral soils, iron is sparingly soluble under aerobic conditions at high pH. Consequently, in calcareous soils, which constitute Ϸ30% of the world's cultivated soils, plants often exhibit iron deficiency symptoms manifested as chlorosis (yellowing caused by chlorophyll deficiency), reducing crop yield and quality (1). Higher plants use two major iron uptake strategies under conditions of low iron supply: reduction (Strategy I) and chelation (Strategy II) (2). The Strategy II mechanism is specific to graminaceous plants and is mediated by natural iron chelators, the mugineic acid family phytosiderophores (MAs) (3). Extensive physiological, biochemical, and molecular studies have identified the biosynthetic pathway of MAs and the genes encoding the biosynthetic enzymes (4-9). The expression of these biosynthetic genes is coordinately upregulated in response to iron deficiency (6,8,9), but the molecular mechanisms regulating these iron deficiency-induced genes are poorly understood.Recent studies have demonstrated that a rice iron deficiencyinduced basic helix-loop-helix (bHLH) transcription factor, Os-IRO2, regulates the Strategy II-based iron deficiency response by inducing the related genes (10, 11). The core sequence to which OsIRO2 binds (CACGTGG) is overrepresented in...

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Section: Resultssupporting

confidence: 93%

The transcription factor IDEF1 regulates the response to and tolerance of iron deficiency in plants

Kobayashi

Ogo²,

Itai³

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

206

219

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“…NA seems to be produced in the endosperm, while DMA is produced in the embryo, especially in the coleorhizae and bud scales. NA and DMA production is also overlapped in the embryo (Nozoye et al 2007). Hence, NA and DMA are synthesized during germination and are involved in Fe translocation during germination.…”

Section: Fe Homeostasis During Germinationmentioning

confidence: 98%

“…IDEF1 and IDEF2 are expressed constitutively during germination in the embryo and endosperm (Kobayashi et al 2010). Moreover, the expression of various genes involved in Fe homeostasis, including OsNAS2-3 and OsNAAT1, increases sharply after germination, indicating that NA and DMA production increases (Nozoye et al 2007). The expression of the Fe transporters OsYSL2 (Fe-NA transporter) and OsIRT1 has been observed during germination.…”

Section: Fe Homeostasis During Germinationmentioning

confidence: 99%

“…Hence, NA and DMA are synthesized during germination and are involved in Fe translocation during germination. Furthermore, the expression of OsIRT1 indicates that rice can utilize both Fe 2+ and Fe 3+ during germination (Nozoye et al 2007;Takahashi et al 2009). The role of Fe transporters during germination has also been studied using knockdown plants.…”

Section: Fe Homeostasis During Germinationmentioning

confidence: 99%

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Iron Uptake and Loading into Rice Grains

Bashir

Ishimaru

Nishizawa

2010

Rice

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115

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“…1 Graminaceous plants utilize a chelation strategy to acquire Fe from soil that involves the secretion of mugineic acid family phytosiderophores (MAs), 2,3 which chelate and solubilize Fe(III) in the rhizosphere from their roots through Transporter Of Mugineic acids 1 (TOM1). 4,5 The resultant Fe(III)-MAs complexes are absorbed by root cells through a transporter protein, Yellow Stripe 1 (YS1)/YS1-Like (YSL). 6,7 Rice produces and secretes 2′-deoxymugineic acid (DMA), which is the first MAs to be biosynthesized.…”

mentioning

confidence: 99%