Getting the green light: How chloroplast gene expression is activated by light

在植物中，光合作用发生在叶绿体内，叶绿体是含有编码光合复合物的基因组的细胞器。植物的生长和存活依赖于这些叶绿体基因响应发育和环境线索的调节表达。例如，暴露在光下会导致光合基因转录的急剧增加。这是植物发育的一个决定性阶段，但是，尽管它很重要，我们不知道它在分子水平上是如何发生的。在这个项目中，我们将研究叶绿体转录是如何开启的，并允许植物变得绿色。该项目将采用各种尖端方法来研究激活基因表达的蛋白质的结构，功能和生物学作用。低温电子显微镜（cryo-EM）将用于可视化基因表达复合物的结构。将进行补充的生物化学和生物物理实验，以了解它们与生物化学活性的关系。最后，这些蛋白质在植物中的重要作用将通过检测靶向突变对叶绿体成熟的影响来进行测试。这些发现将支持长期努力，以更好地控制光合作用的输出和改进作物和生物技术的时间。它们还将为如何读取基因等基本生物学问题提供新的线索。

In plants, photosynthesis occurs within chloroplasts, organelles that contain a genome encoding photosynthetic complexes. Growth and survival of plants depends on regulated expression of these chloroplast genes in response to developmental and environmental cues. For example, exposure to light causes a dramatic increase in the transcription of photosynthetic genes. This is a defining stage of plant development, but, despite its importance, we do not know how it occurs at the molecular level. In this project, we will investigate how chloroplast transcription is turned on and allow plants to become green. This project will employ a variety of cutting-edge methods to characterise the structures, functions and biological roles of proteins that activate gene expression. Cryogenic electron microscopy (cryo-EM) will be employed to visualise the structure of gene expression complexes. Complementary biochemical and biophysical experiments will be performed to understand the relationship to their biochemical activities. Finally, the essential roles of these proteins in plants will be tested by examining the effect of targeted mutations on chloroplast maturation. These discoveries will support the long-term effort to better control photosynthetic output and timing for improved crops and biotechnologies. They will also shed new light on fundamental biological questions of how genes are read.