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中，叶绿体是含有编码光合复合体基因组的细胞器。植物的生长和存活取决于这些叶绿体基因的调控表达，以响应发育和环境的线索。例如，暴露在光线下会导致光合作用基因的转录急剧增加。这是植物发育的一个决定性阶段，但是，尽管它很重要，我们不知道它是如何在分子水平上发生的。在这个项目中，我们将研究叶绿体转录是如何开启并使植物变绿的。该项目将采用各种尖端方法来表征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）将用于观察基因表达复合物的结构。补充的生化和生物物理实验将进行，以了解他们的生化活动的关系。最后，这些蛋白质在植物中的重要作用将通过检测目标突变对叶绿体成熟的影响来测试。这些发现将支持更好地控制光合作用输出和改良作物和生物技术的时机的长期努力。它们还将为基因解读的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.