Arabidopsis Cys2/His2-type zinc-finger proteins function as transcription repressors under drought, cold, and high-salinity stress conditions
Arabidopsis Cys2/His2-type zinc-finger proteins function as transcription repressors under drought, cold, and high-salinity stress conditions
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DOI：
10.1104/pp.104.046599
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发表时间：
2004-09-01
期刊：
影响因子：
7.4
通讯作者：
Yamaguchi-Shinozaki, K
中科院分区：
文献类型：
--
作者：
Sakamoto, H;Maruyama, K;Yamaguchi-Shinozaki, K
ZPT 2相关蛋白是植物转录因子家族的成员，其分子中含有两个典型的Cys-2/His-2型锌指基序。为了表征这种类型的蛋白质的作用，我们分析了拟南芥L，Heynh。编码四种不同ZPT 2相关蛋白（AZF 1，AZF 2，AZF 3和STZ）的基因。凝胶位移分析表明，AZF和STZ结合到EP 2序列内的A（G/C）T重复序列，EP 2序列被称为一些矮牵牛（Petunia hybrida）ZPT 2蛋白的靶序列。使用合成的绿色荧光蛋白融合基因的瞬时表达分析表明，AZF和STZ优先定位于细胞核。这四种ZPT 2相关蛋白被证明是转录抑制因子，下调其他转录因子的反式激活活性。RNA凝胶印迹分析表明，AZF 2和STZ的表达强烈诱导脱水，高盐和冷胁迫，脱落酸处理。由AZF 2或STZ启动子驱动的β-葡萄糖醛酸酶活性的组织化学分析显示，这两个基因在莲座丛植物的叶中而不是根中被胁迫诱导。过量表达STZ的转基因拟南芥表现出生长迟缓和对干旱胁迫的耐受。这些结果表明，AZF 2和STZ作为转录抑制因子的功能，以增加胁迫耐受性生长迟缓。
ZPT2-related proteins that have two canonical Cys-2/His-2-type zinc-finger motifs in their molecules are members of a family of plant transcription factors. To characterize the role of this type of protein, we analyzed the function of Arabidopsis L, Heynh. genes encoding four different ZPT2-related proteins (AZF1, AZF2, AZF3, and STZ). Gel-shift analysis showed that the AZFs and STZ bind to A(G/C)T repeats within an EP2 sequence, known as a target sequence of some petunia (Petunia hybrida) ZPT2 proteins. Transient expression analysis using synthetic green fluorescent protein fusion genes indicated that the AZFs and STZ are preferentially localized to the nucleus. These four ZPT2-related proteins were shown to act as transcriptional repressors that down-regulate the transactivation activity of other transcription factors. RNA gel-blot analysis showed that expression of AZF2 and STZ was strongly induced by dehydration, high-salt and cold stresses, and abscisic acid treatment. Histochemical analysis of beta-glucuronidase activities driven by the AZF2 or STZ promoters revealed that both genes are induced in leaves rather than roots of rosette plants by the stresses. Transgenic Arabidopsis overexpressing STZ showed growth retardation and tolerance to drought stress. These results suggest that AZF2 and STZ function as transcriptional repressors to increase stress tolerance following growth retardation.