Abstract：
Chlorophyll (Chl) plays a crucial role in photosynthesis, functioning as a photosensitizer. As an integral component of this process, energy absorbed by this pigment is partly emitted as red fluorescence. This signal can be readily imaged by fluorescence microscopy and provides a visualization of photosynthetic activity. However, due to limited resolution, signals cannot be assigned to specific subcellular/organellar membrane structures. By correlating fluorescence micrographs with transmission electron microscopy, researchers can identify sub-cellular compartments and membranes, enabling the monitoring of Chl distribution within thylakoid membrane substructures in cyanobacteria, algae, and higher plant single cells. Here, we describe a simple and effective protocol for correlative light-electron microscopy (CLEM) based on the autofluorescence of Chl and demonstrate its application to selected photosynthetic model organisms. Our findings illustrate the potential of this technique to identify areas of high Chl concentration and photochemical activity, such as grana regions in vascular plants, by mapping stacked thylakoids.
摘要：
叶绿素（Chl）在光合作用中起着至关重要的作用，作为光敏剂。作为这个过程的一个组成部分，这种颜料吸收的能量部分发射为红色荧光。该信号可以通过荧光显微镜容易地成像并提供光合活性的可视化。然而,由于分辨率有限，信号不能分配给特定的亚细胞/细胞器膜结构。通过将荧光显微照片与透射电子显微镜相关联，研究人员可以识别亚细胞区室和膜，能够监测蓝藻类囊体膜亚结构内的Chl分布，藻类,和高等植物单细胞。这里,我们描述了基于Chl的自发荧光的相关光电子显微镜（CLEM）的简单有效方案，并展示了其在选定的光合模型生物中的应用。我们的发现说明了该技术识别高Chl浓度和光化学活性区域的潜力，例如维管植物中的grana区域，通过绘制堆叠的类囊体。
