Loyall L, Uchida K, Braun S, Furuya M, Frohnmeyer H
Biologisches Institut II/Botanik, Albert-Ludwigs-Universitaet, D-79104 Freiburg, Schaenzlestrasse 1, Germany.
Plant Cell. 2000 Oct;12(10):1939-50. doi: 10.1105/tpc.12.10.1939.
UV irradiation stimulates expression of the gene encoding the key enzyme chalcone synthase (CHS), which leads to the generation of protective flavonoids in parsley cell cultures. CHS transcripts increase after 3 to 4 hr, and early genes are involved in the signal transduction to the CHS promoter. By using the fluorescent differential display technique in a large-scale screening, several early UV light-induced genes were isolated. Of these, a novel glutathione S-transferase (PcGST1) is induced within 2 hr and precedes CHS expression. Overexpression of PcGST1 in transformed cell lines containing a CHS promoter/luciferase reporter (CHS-LUC) affected the onset of LUC transcription. Supplementing these cell lines with glutathione immediately stimulated CHS-LUC expression within 2 hr in dark-incubated cells and resulted in a biphasic induction profile in UV-irradiated cells. Our data indicate the involvement of glutathione and PcGST1 in early events of a UV light-dependent signal transduction pathway to CHS. In this context, the oxidative status of a cell acts as a central regulating element.
紫外线照射可刺激编码关键酶查尔酮合酶（CHS）的基因表达，这会导致在 parsley 细胞培养物中生成保护性类黄酮。CHS 转录本在 3 至 4 小时后增加，早期基因参与向 CHS 启动子的信号转导。通过在大规模筛选中使用荧光差异显示技术，分离出了几个早期紫外线诱导基因。其中，一种新型谷胱甘肽 S-转移酶（PcGST1）在 2 小时内被诱导，且先于 CHS 表达。在含有 CHS 启动子/荧光素酶报告基因（CHS-LUC）的转化细胞系中过表达 PcGST1 影响了 LUC 转录的起始。在黑暗培养的细胞中，用谷胱甘肽补充这些细胞系可在 2 小时内立即刺激 CHS-LUC 表达，并在紫外线照射的细胞中产生双相诱导模式。我们的数据表明谷胱甘肽和 PcGST1 参与了紫外线依赖性信号转导途径至 CHS 的早期事件。在此背景下，细胞的氧化状态起着核心调节作用。
