An unidentified ultraviolet-B-specific photoreceptor mediates transcriptional activation of the cyclobutane pyrimidine dimer photolyase gene in plants
An unidentified ultraviolet-B-specific photoreceptor mediates transcriptional activation of the cyclobutane pyrimidine dimer photolyase gene in plants
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DOI：
10.1007/s00425-008-0803-4
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发表时间：
2008-12-01
期刊：
影响因子：
4.3
通讯作者：
Kondo, Noriaki
中科院分区：
文献类型：
--
作者：
Ioki, Motohide;Takahashi, Shinya;Kondo, Noriaki
环丁烷嘧啶二聚体(CPDS)构成了紫外线B(UVB)引起的DNA损伤的大部分。CPD光解酶能够快速修复CPD，是植物在含有UVB的阳光下生存所必需的。我们早期关于黄瓜CPD光解酶基因(CsPHR)的转录被光激活的结果促使我们提出，这种光驱动的转录激活将使植物能够满足紫外线对阳光的挑战所需的光解酶活性。然而，CsPHR光依赖转录激活的分子机制尚不清楚。为了了解植物反应的光谱方面，我们研究了CsPHR光依赖转录激活的波长依赖性(作用光谱)。在黄瓜幼苗和CsPHR启动子控制下表达报告基因的转基因拟南芥幼苗中，作用光谱在长波UVB波段(约310 nm)显示出最明显的峰值。此外，CsPHR启动子中95个碱基的顺式作用区域对于UVB诱导的CsPHR转录激活是必不可少的。因此，我们得出结论，UVB光感受器(S)对长波UVB的光接收导致了CsPHR转录的诱导，这是通过一个保守的顺式作用元件来实现的。
Cyclobutane pyrimidine dimers (CPDs) constitute a majority of DNA lesions caused by ultraviolet-B (UVB). CPD photolyase, which rapidly repairs CPDs, is essential for plant survival under sunlight containing UVB. Our earlier results that the transcription of the cucumber CPD photolyase gene (CsPHR) was activated by light have prompted us to propose that this light-driven transcriptional activation would allow plants to meet the need of the photolyase activity upon challenges of UVB from sunlight. However, molecular mechanisms underlying the light-dependent transcriptional activation of CsPHR were unknown. In order to understand spectroscopic aspects of the plant response, we investigated the wavelength-dependence (action spectra) of the light-dependent transcriptional activation of CsPHR. In both cucumber seedlings and transgenic Arabidopsis seedlings expressing reporter genes under the control of the CsPHR promoter, the action spectra exhibited the most predominant peak in the long-wavelength UVB waveband (around 310 nm). In addition, a 95-bp cis-acting region in the CsPHR promoter was identified to be essential for the UVB-driven transcriptional activation of CsPHR. Thus, we concluded that the photoperception of long-wavelength UVB by UVB photoreceptor(s) led to the induction of the CsPHR transcription via a conserved cis-acting element.