The transcription factor IDEF1 regulates the response to and tolerance of iron deficiency in plants
The transcription factor IDEF1 regulates the response to and tolerance of iron deficiency in plants
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DOI：
10.1073/pnas.0707010104
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发表时间：
2007-11-27
影响因子：
11.1
通讯作者：
Nishizawa, Naoko K.
中科院分区：
文献类型：
--
作者：
Kobayashi, Takanori;Ogo, Yuko;Nishizawa, Naoko K.
铁是大多数生物所必需的，通常也是正常生长的主要限制营养物质。植物在缺铁条件下诱导铁利用系统，但缺铁条件下基因调控的分子机制仍不清楚。我们鉴定了水稻转录因子IDEF1，它与铁缺乏反应顺式作用元件IDE1特异性结合。IDEF1属于植物特异转录因子家族AB13/VP1中的一个未知分支，具有与IDE1中的CATGC序列有效结合的序列识别特性。IDEF1转录本主要存在于水稻的根和叶中。在花椰菜花叶病毒35S启动子控制下表达IDEF1的转基因烟草只在缺铁的根中反式激活IDE1介导的表达。在水培和石灰性土壤中，表达IDEF1基因的转基因水稻植株对缺铁表现出很强的耐受性。IDEF1的过表达导致铁缺乏诱导的转录因子基因Os/RO2的表达增强，这表明存在一个顺序的基因调控网络。这些发现揭示了顺式元件/反式因子的相互作用在功能上与缺铁反应有关。对IDEF1的操作也为生产耐缺铁作物提供了另一种方法，以提高石灰性土壤的粮食产量和生物量。
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 AB13/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 Os/RO2, 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.