seedlings. Extreme skewing was observed at the root apex and proximal root. The roots skewed
only slightly on the ground controls in comparison to flight controls. This leads to the conclusion
that plants have endogenous growth patterns that are largely masked in normal 1 g conditions
found on Earth. Another major difference was noted between the amount of adventitious roots
(roots formed from shoot tissues) found on the flight and ground samples. This adds to the idea
that microgravity produces an increase in mitosis in the pericycle, thus producing a larger
number of adventitious roots. It is also believed that with previous and present experiments
that microgravity may induce alterations in essential cell functions that may be related to cell
cycle regulation (Millar 2011).
BRIC-16-DNA
Previous studies determined
that plants exhibit adaptive
behaviors in response to
spaceflight. One specific study
looked to determine if cell
cultures of Arabidopsis
thaliana were able to
perceive and respond to
spaceflight. This study
determined that only under
constant clinorotation
(rotation about an axis) were
these cells able to induce heat
shock proteins. This led to the
conclusion that even
nondifferentiated cells are
able to sense and react to
gravity (Zupanska 2012).
BRIC-16-DNA addressed these
issues by producing replicable
results in order to answer
fundamental questions using
current gene profiling technologies. Seedlings and cell cultures both respond to microgravity by
altering specific gene expressions in entirely different responses. A possible explanation for the
differences between cultured cells and seedlings is due to the fact that seedlings use their
organs to sense and sample their environment, and that undifferentiated cell cultures, lacking
such organs propagate inappropriate stress responses. Another possibility is that all the cells in
the culture were responding unanimously, while distinct tissue-types in the seedlings
responded differently (Paul 2012).
BRIC-16-REGULATION
Results are pending publication.
Spaceflight and Ground Control biology after landing. Representative
pictures of the plant materials removed from their respective Petri
Dish Fixation Units.