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

Reference ID

25482

Title

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

Source

Proceedings of the National Academy of Sciences of the United States of America, 2007, vol. 104, pp. 19150-19155

Authors (7)

Kobayashi-T	Ogo-Y
Itai-R-N	Nakanishi-H
Takahashi-M	Mori-S
Nishizawa-N-K

Abstract

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.