Diurnal change of cucumber CPD photolyase gene (CsPHR) expression and its physiological role in growth under UV-B irradiation.
Diurnal change of cucumber CPD photolyase gene (CsPHR) expression and its physiological role in growth under UV-B irradiation.
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UV-B 照射下黄瓜 CPD 光解酶基因 (CsPHR) 表达的日变化及其在生长中的生理作用。
DOI：
10.1093/pcp/pcf038
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发表时间：
2002
影响因子：
4.9
通讯作者：
N. Kondo
中科院分区：
文献类型：
--
作者：
Shinya Takahashi;N. Nakajima;H. Saji;N. Kondo
从黄瓜叶片中分离到编码环丁烷嘧啶二聚体(CPD)专一性DNA光解酶(CPD光解酶)的互补DNA。其推导的氨基酸序列与拟南芥CPD光解酶的氨基酸序列高度相似。用该基因转化一株大肠杆菌突变体，恢复了受损的光修复活性，表明该基因编码黄瓜CPD光解酶(CsPHR)。定量RT-PCR法测定的CsPHR转录本水平和CPD光修复活性均呈日变化，分别在09：00和12：00达到峰值。在光期中期补充UV-B辐射对第一片叶片的生长影响不大，而在清晨或傍晚补充UV-B辐射对叶片生长有强烈的抑制作用。这些结果表明，CPD光修复活性的日变化可能是由CsPHR的转录水平调节的，这可能在减少UV-B辐射对生长的抑制方面发挥了重要作用。
Complementary DNA encoding a putative cyclobutane pyrimidine dimer (CPD)-specific DNA photolyase (CPD photolyase) was isolated from cucumber leaves. The deduced amino acid sequence of the cDNA exhibited high similarity to that of the Arabidopsis CPD photolyase. Transformation with the cDNA restored the impaired photorepair activity of an Escherichia coli mutant, indicating that this cDNA encodes a functional cucumber CPD photolyase (CsPHR). The level of CsPHR transcripts estimated by quantitative RT-PCR as well as the CPD photorepair activity in the cucumber first leaves showed diurnal changes, peaking at 09 : 00 and 12 : 00, respectively. Supplemental UV-B irradiation in the middle of the light period had little effect on the growth of the first leaves, while the supplemental irradiation in the early morning or late afternoon strongly retarded the leaf growth. These results suggest that the diurnal change in CPD photorepair activity, which is presumably regulated by the transcript level of CsPHR, may play an important role in minimizing the growth inhibition due to UV-B irradiation.