Cell
Biology
We use
many cell biological and microscope-based approaches to test how signaling
molecules may act in plant cells.
Examples of these approaches include microinjecting single cells with
chemically modified signaling molecules (caged molecules) which we
can switch on (photoactivate) with UV light and observing the response
of that individual cell to activating the signaling molecule.
(Click on a picture to download a higer resolution version)
Manipulating
cytoplasmic calcium levels in a living, functioning barley aleurone
cell.
This cell
has been loaded with an indicator of cytoplasmic calcium levels and
a compound that releases calcium upon UV illumination. Using UV pulses
from a laser we can release known amounts of calcium into the cytoplasm
of the cell. By manipulating calcium levels in this way we can test
how these changes might participate in the transduction of the hormonal
signals in these cells. Times are in minutes.
In order to
test the activity of single cells we are developing approaches such
as being able to image the secretory activity of a single cell. Here
an aleurone cell (Pr) is embedded in starch (S). The hormonally stimulated
cell (on the right) but not the non-treated cell (on the left) has digested
a clear 'halo' (h) in the blue stained starch which we can visualize
down the microscope.
We are also using other microscope technologies such as confocal microscopy,
microinjection and computer-based image analysis to observe how plant
cells respond to stimuli.
