appearance (Morrow 2004). By the end of the 73-day experiment, BPS TVT produced a total of
8 harvests, 7 primings, and a plant tissue archive of more than 300 plants.
Gross measure of growth, leaf chlorophyll, starch, and soluble carbohydrates confirmed
comparable performance by the plants on the station with ground controls. Of particular
interest were the differences between the immature seedlings. Immature seeds from station
had higher concentrations of chlorophyll, starch, and soluble carbohydrates than the ground
controls. Seed protein was significantly lower in the ISS material. Also, microscopy of immature
seeds fixed on ISS showed embryos to be at a range of developmental stages, while ground
control embryos had all reached the same stage of development. These differences could be
attributable to differences in water delivery or reduced gas exchange due to lack of convection.
These results suggest that the microgravity environment may affect flavor and nutritional
quality on potential space produce (Musgrave 2005).
An ancillary study tested for bacterial and fungal communities in the BPS chambers and root
modules, and these cultures were compared to ground control bacterial and fungal growth.
Analysis indicated more species of both bacteria and fungus were identified in the flight
samples than the ground samples. The populations were common airborne species found on
Earth. The significance of the difference is uncertain (Frazier 2003).
PUBLICATION(S)
Allen J, Bisbee PA, Darnell RL, et al. Gravity control of growth form in Brassica rapa and
Arabidopsis thaliana (Brassicaceae): Consequences for secondary metabolism. American Journal
of Botany. 2009;96(3):652-660.
Stutte GW, Monje O, Hatfield RD, Paul A, Ferl RJ, Simone CG. Microgravity effects on leaf
morphology, cell structure, carbon metabolism and mRNA expression of dwarf wheat. Planta.
2006;224:1038-1049. doi: 10.1007/s00425- 006 -0290-4.
Monje O, Stutte GW, Chapman DK. Microgravity does not alter plant stand gas exchange of
wheat at moderate light levels and saturating CO2 concentration. Planta. 2005;222(2):336-345.
doi: 10.1007/s00425- 005 -1529-1.
Musgrave ME, Kuang A, Tuominen LK, Levine LH, Morrow RC. Seed storage reserves and
glucosinolates in Brassica rapa L. Grown on the International Space Station. Journal of the
American Society for Horticultural Science. 2005;130(6):848-856.
Stutte GW, Monje O, Goins GD, Tripathy BC. Microgravity effects on thylakoid, single leaf, and
whole canopy photosynthesis on dwarf wheat. Planta. 2005:1-11. doi: 10.1007/s00425- 005 -
0066 -2.
Morrow RC, Iverson JT, Richter RC, Stadler JJ. Biomass Production System (BPS) technology
validation test results. International Conference on Environmental Systems, Colorado Springs,
CO; July 19 , 2004 1061-1070.