Dual function of an Arabidopsis transcription factor DREB2A in water-stress-responsive and heat-stress-responsive gene expression
Dual function of an Arabidopsis transcription factor DREB2A in water-stress-responsive and heat-stress-responsive gene expression
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DOI：
10.1073/pnas.0605639103
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发表时间：
2006-12-05
影响因子：
11.1
通讯作者：
Yamaguchi-Shinozaki, Kazuko
中科院分区：
文献类型：
--
作者：
Sakuma, Yoh;Maruyama, Kyonoshin;Yamaguchi-Shinozaki, Kazuko
转录因子DRIEB 2A与顺式作用的脱水反应元件（DRE）序列相互作用并激活参与拟南芥干旱和盐胁迫响应的下游基因的表达。在正常生长条件下，完整的DREB 2A表达不会激活下游基因。DREB 2A的中心区域存在负调控结构域，该区域的缺失将DREB 2A转化为组成型活性形式（DREB 2A CA）。我们进行了基因芯片分析的转基因拟南芥过表达DREB 2A CA，发现DREB 2A CA的过表达不仅诱导干旱和盐响应基因，但也热休克（HS）相关基因。此外，我们发现，短暂的诱导DREB 2A发生迅速HS应激，和sGFP-DREB 2A蛋白积累在HS应激细胞的细胞核。DREB 2A上调基因根据其表达模式分为3类：HS诱导基因、干旱胁迫诱导基因和HS和干旱胁迫共同诱导基因。DREB 2A基因敲除突变体在胁迫条件下表达下调。耐热性显着增加的植物过表达DREB 2A CA和降低DREB 2A基因敲除植物。总的来说，这些结果表明DREB 2A在水和HS胁迫反应中起作用。
Transcription factor DRIEB2A interacts with a cis-acting dehydration-responsive element (DRE) sequence and activates expression of downstream genes involved in drought- and salt-stress response in Arabidopsis thaliana. Intact DREB2A expression does not activate downstream genes under normal growth conditions. A negative regulatory domain exists in the central region of DREB2A, and deletion of this region transforms DREB2A to a constitutive active form (DREB2A CA). We carried out microarray analysis of transgenic Arabidopsis-overexpressing DREB2A CA and found that the overexpression of DREB2A CA induces not only drought- and salt-responsive genes but also heat-shock (HS)-related genes. Moreover, we found that transient induction of the DREB2A occurs rapidly by HS stress, and that the sGFP-DREB2A protein accumulates in nuclei of HS-stressed cells. DREB2A up-regulated genes were classified into three groups based on their expression patterns: genes induced by HS, genes induced by drought stress, and genes induced by both HS and drought stress. DREB2A up-regulated genes were down-regulated in DREB2A knockout mutants under stress conditions. Thermotolerance was significantly increased in plants overexpressing DREB2A CA and decreased in DREB2A knockout plants. Collectively, these results indicate that DREB2A functions in both water and HS-stress responses.