Chris Halnon, Erika Gehr, Brandon Kocher
|
Vinca 'Nirvana Cascade' |
|
Impatiens sp. |
The larger subunit of the protein ribulose bisphosphate carboxylase (RBCL),
transcribed by the chloroplast genome, plays an important role in fixing carbon
in the photosynthetic pathway. Previous research has shown that increased light
intensity decreases the number of chloroplasts present in plant tissues and
protein expression levels increase. Here we investigated RBCL gene quantity and protein expression among flowering plants of differing
light intensities, Impatiens sp. which prefers sun and Nirvana Cascade
which prefers shade. Both plants were grown in full sun and full shade
conditions outside during early fall in a temperate climate. We hypothesize
that treating these plant species in both optimal and non optimal light
conditions the will shift gene transcription and translation to compensate for
the new environment. Quantification of the RBCL gene was higher in both of our
Nirvana treatments and less in both our treatments of the
Impatiens sp. Protein analysis of our plants yielded a relatively greater
expression of RBCL protein in Nirvana grown in full sun based upon
Western blot results. This implies that the plant turns up protein
expression, possibly to fix as much carbon as possible in an energy starved
environment. Hopefully in future experiments, with better technique, we can
investigate further the molecular mechanisms that enable flowering plants with
light intensity preferences to respond to non-optimal light conditions.
| Photos: Michigan West Shore Nursery (2007) http://www.michiganwestshore.com/Annuals/606Flower.html |
kocherba@jmu.edu
Introduction