Download Cryo-preserved plant leaves

Cryo-preserved
plant leaves
CfAM Micronote 109
The leaves of plants have a highly organised internal structure.
These images show a cross section through a single
Cotoneaster leaf.
Just below the surface of the leaf (at the top of this image) is
the palisade mesophyll. This is a tissue composed of layers of
closely packed elongated cells. The main function of these
cells is to capture the light energy which plants use to produce
sugars via photosynthesis. The cells shape and arrangement
ensures they intercept the maximum amount of light.
Below the palisade mesophyll is the spongy mesophyll. Cells
in this tissue are more irregularly shaped and loosely packed
together. This image clearly shows the air spaces which exist
within the spongy mesophyll. It is within this tissue that gas
exchange take place.
(scale bar = 100 micrometres)
Image 2
This image shows a close up of the palisade mesophyll. Each
sausage-shaped object is a single cell. Fine hair-like structures
can be seen linking the cells together.
These are
plasmodesmata, tiny tubes which connect the interior of
adjacent cells. Materials produced by the cells can be moved
short distances through the plasmodesmata.
The oxygen produced in these cells during photosynthesis
diffuses into the air spaces in the spongy mesophyll and out of
the leaf via the stomata (see micronote 104).
(scale bar = 20 micrometres)
Microscopists –Chris Stain
These images were obtained using the cryo-stage facility on the
FEI Quanta FEG Environmental Scanning Electron
Microscope in the Centre for Advanced Microscopy. The
cryo-stage makes is possible to examine delicate specimens in
a frozen state. This can preserve fine details which might
otherwise not be seen.
.
Centre for Advanced Microscopy
University of Reading, Whiteknights, Reading RG6 6AF
Tel (0118) 378 6118, www.reading.ac.uk/cfam
Secondary Structure