The novel protein DELAYED PALE-GREENING1 is required for early chloroplast biogenesis in Arabidopsis thaliana.
The novel protein DELAYED PALE-GREENING1 is required for early chloroplast biogenesis in Arabidopsis thaliana.
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拟南芥早期叶绿体生物发生需要新型蛋白质 DELAYED PALE-GREENING1
DOI：
10.1038/srep25742
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发表时间：
2016-05-10
影响因子：
4.6
通讯作者：
Cheng J
中科院分区：
文献类型：
--
作者：
Liu D;Li W;Cheng J
叶绿体生物发生是植物生物学的重要研究课题之一。在这项研究中，拟南芥早期叶绿体生物发生突变体与延迟苍白绿化表型（dpg 1）的T-DNA插入突变体收集分离。dpg 1突变体的子叶和真叶最初都是白化病的，但随着植株的成熟逐渐变成淡绿色。透射电子显微镜观察显示，该突变体表现出延迟的前质体到叶绿体的转变。序列和转录分析表明，AtDPG 1编码一个pupillary叶绿体定位的蛋白含有三个预测的跨膜螺旋，它的表达依赖于光和发育状态。对AtDPG 1：：GUS转基因株系的GUS染色表明，该基因在整个植株中广泛表达，并且在拟南芥幼苗发育的早期阶段，在绿色组织中主要发现较高的表达水平。此外，定量实时RT-PCR分析表明，一些叶绿体和核编码的基因参与叶绿素合成，光合作用和叶绿体发育的dpg 1突变体中大幅下调。这些数据表明，AtDPG 1在早期叶绿体生物发生中起着至关重要的作用，它的缺乏触发叶绿体到核的逆行信号，最终下调编码叶绿体定位蛋白的核基因的表达。
Chloroplast biogenesis is one of the most important subjects in plant biology. In this study, an Arabidopsis early chloroplast biogenesis mutant with a delayed pale-greening phenotype (dpg1) was isolated from a T-DNA insertion mutant collection. Both cotyledons and true leaves of dpg1 mutants were initially albino but gradually became pale green as the plant matured. Transmission electron microscopic observations revealed that the mutant displayed a delayed proplastid-to-chloroplast transition. Sequence and transcription analyses showed that AtDPG1 encodes a putatively chloroplast-localized protein containing three predicted transmembrane helices and that its expression depends on both light and developmental status. GUS staining for AtDPG1::GUS transgenic lines showed that this gene was widely expressed throughout the plant and that higher expression levels were predominantly found in green tissues during the early stages of Arabidopsis seedling development. Furthermore, quantitative real-time RT-PCR analyses revealed that a number of chloroplast- and nuclear-encoded genes involved in chlorophyll biosynthesis, photosynthesis and chloroplast development were substantially down-regulated in the dpg1 mutant. These data indicate that AtDPG1 plays an essential role in early chloroplast biogenesis and its absence triggers chloroplast-to-nucleus retrograde signalling, which ultimately down-regulates the expression of nuclear genes encoding chloroplast-localized proteins.