Studying the Supramolecular Organization of Photosynthetic Membranes within Freeze-fractured Leaf Tissues by Cryo-scanning Electron Microscopy

J Vis Exp. 2016 Jun 23:(112):54066. doi: 10.3791/54066.

Abstract

Cryo-scanning electron microscopy (SEM) of freeze-fractured samples allows investigation of biological structures at near native conditions. Here, we describe a technique for studying the supramolecular organization of photosynthetic (thylakoid) membranes within leaf samples. This is achieved by high-pressure freezing of leaf tissues, freeze-fracturing, double-layer coating and finally cryo-SEM imaging. Use of the double-layer coating method allows acquiring high magnification (>100,000X) images with minimal beam damage to the frozen-hydrated samples as well as minimal charging effects. Using the described procedures we investigated the alterations in supramolecular distribution of photosystem and light-harvesting antenna protein complexes that take place during dehydration of the resurrection plant Craterostigma pumilum, in situ.

Publication types

  • Video-Audio Media

MeSH terms

  • Freeze Fracturing
  • Light-Harvesting Protein Complexes
  • Microscopy, Electron
  • Microscopy, Electron, Scanning*
  • Photosynthesis
  • Plant Leaves

Substances

  • Light-Harvesting Protein Complexes