Mark, regarding your request for starch assay in plant leaves (request
below), I have had some experience with determining water soluble
carbohydrate (WSC) content and "total nonstructural carbohydrate" (TNC)
content; then, determining STARCH indirectly by subtraction of WSC from
TNC.
N.J. Chatterton and J.E. Silvius. 1981. Photosynthate partitioning into
starch in soybean leaves. II. Irradiance level and daily photosynthetic
period duration effects. Plant Physiology 67: 257-260.
John E. Silvius
Professor of Biology
Cedarville College
Box 601
Cedarville, OH 45314
>>> Mark A Vandermeulen <vander+ at pitt.edu> 12/02 7:23 PM >>>
Greetings
I am a graduate student in the Ecology and Evolution section at
the University of Pittsburgh. My advisor (Steven Tonsor) and I are
interested in setting up a research project investigating the norms of
reaction of a number of plant traits in _Arabidopsis thaliana_ to elevated
carbon dioxide levels. Plants grown under elevated CO2 typically exhibit
increased sugar levels in their leaves and down-regulation of activity of
RubisCO as well as its transcription. However, these changes do not appear
to be largely adaptive; many plants appear unable to allocate this extra
energy to increased growth and reproduction. To further examine this
phenomenon, we are interested in assays that we could use to quantify the
following properties: 1.) sugar concentrations in plant organs, 2.) starch
concentrations in plant organs, 3.) some measure of the relative amounts
of their nitrogen budget plants are spending on building and maintaining
their photosynthetic apparatus, and 4.) some measure of the relative
amount of their nitrogen budget plants are spending on proteins associated
with starch anabolism. Any assay that is selected will need to be
reasonably cheap and time effective, because the nature of phenotypic
plasticity studies nessitates sampling a large number of individuals (and
thus we thought that this forum may be an appropriate place for
assistance). We would be very interested in any citations that the members
of this forum could supply for such assays, as well as discussion of their
relative merits and weaknesses.
Sincerely,
Mark VanderMeulen
vander+ at pitt.edu
