Wound-induced expression of the FAD7 gene is mediated by different regulatory domains of its promoter in leaves/stems and roots
Wound-induced expression of the FAD7 gene is mediated by different regulatory domains of its promoter in leaves/stems and roots
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DOI：
10.1104/pp.121.4.1239
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发表时间：
1999-12-01
期刊：
影响因子：
7.4
通讯作者：
Iba, K
中科院分区：
文献类型：
--
作者：
Nishiuchi, T;Kodama, H;Iba, K
FAD7基因在未受伤植物的叶绿素组织中优先表达。损伤激活FAD的表达；基因不仅存在于叶绿素组织中，也存在于茎和根的非叶绿素组织中。我们之前的研究表明，叶片/茎和根中FAD7启动子的创伤应答转录激活分别由茉莉酸（JA）非依赖性和JA依赖性信号通路引起。在本文中，我们发现FAD7启动子中的一个特定区域（从-259到-198）是该基因在叶片和茎中伤口激活表达所必需的，而另一个区域（从-521到-363）不仅是伤口激活的必要区域，也是该基因在根中ja响应表达所必需的。因此，FAD7启动子的不同调控区域介导了该基因在叶片/茎和根中不同的损伤诱导表达。凝胶迁移位移分析显示，在茎和叶核提取物中，伤口诱导的dna结合活性均为-242/-223区。事实上，该区域的删除消除了FAD7启动子的伤口反应，提示该位点在体内的作用。此外，我们检测到根核因子与该启动子的-433至-363区域相互作用。伤害和茉莉酸甲酯处理诱导的dna结合活性不同。这些结果表明，不同的调控机制介导了空中和地下器官中创伤诱导的FAD7基因的表达。
The FAD7 gene is expressed preferentially in the chlorophyllous tissues of unwounded plants. Wounding activates the expression of the FAD; gene not only in chlorophyllous tissues, but also in nonchlorophyllous tissues of stems and roots. Our previous study suggested that wound-responsive transcriptional activation by the FAD7 promoter in leaves/stems and roots is brought about by a jasmonic acid (JA)-independent and JA-dependent signaling pathway, respectively. In this paper, we show that a specific region (from -259 to -198) in the FAD7 promoter is required for wound-activated expression of this gene in leaves and stems, while another region (from -521 to -363) is necessary not only for wound-activated but also for JA-responsive expression of this gene in roots. Thus, different regulatory regions of the FAD7 promoter mediate distinct wound-induced expression of this gene in leaves/stems and roots. Gel mobility shift assays revealed the wound-inducible DNA-binding activity to the -242/-223 region in both stem and leaf nuclear extracts. In fact, deletion of this region abolished wound response of the FAD7 promoter, suggesting the in vivo role of this site. Furthermore, we detected root nuclear factors interacting with the region from -433 to -363 of this promoter. Wounding and methyl jasmonate treatments induced differently these DNA-binding activities. These results suggest that different regulatory mechanisms mediate the wound-induced expression of the FAD7 gene in aerial and subterranean organs.