Microgravity Effects on Early Reproductive Development in Plants

Plant biology

Arabidopsis thaliana (mouse-ear cress)
Flight seedlings: 30

48-Hour asynchronous ground control using the Orbiter Environmental Simulator

Plant Growth Unit, Atmospheric Exchange System

The primary objective of CHROMEX-05 was to determine if plants grown in space are infertile due to microgravity, or some other environmental factor like the lack of convection. This was the third flight of this experiment. An Atmospheric Exchange System was flown on this flight but not on the two previous, to determine if air movement has an effect on reproductive development.

For this experiment, 13-day-old mouse-ear cress (Arabidopsis thaliana) seedlings were grown in space and were compared to plants grown under similar conditions on Earth. These plants initiated flowering shoots while on orbit. Plants were retrieved from the orbiter 2–3 hours after landing and reproductive material was immediately processed for in vivo observations of pollen viability, pollen tube growth, and esterase activity in the stigma, or fixed for later microscopy. An Atmospheric Exchange System was used on this flight to provide slow purging of the plant growth chambers with filtered cabin air.

Under the conditions of this flight, the space flight plants had reproductive development comparable to the ground controls, and immature seeds were produced. These results represent the first report of successful plant reproduction on the Space Shuttle.

Kuang, A. et al.: Control of Seed Development in Arabidopsis thaliana by Atmospheric Oxygen. Plant, Cell and Environment, vol. 21(1), 1998, pp. 71–78.

Kuang, A. et al.: Cytochemical Localization of Reserves during Seed Development in Arabidopsis thaliana under Spaceflight Conditions. Annals of Botany, vol. 78, 1996, pp. 343–351.

Kuang, A. et al.: Dynamics of Vegetative Cytoplasm during Generative Cell Formation and Pollen Maturation in Arabidopsis thaliana. Protoplasma, vol. 194, 1996, pp. 81–90.

Musgrave, M.E. et al.: Plant Reproduction during Spaceflight. Planta, vol. 203, 1997, pp. S177–S184.

Musgrave, M.E. et al.: Plant Reproduction in Spaceflight Environments. Gravitational and Space Biology Bulletin, vol. 10(2), Jun 1997, pp. 83–90.

Porterfield, D.M. et al.: Changes in Soluble Sugar, Starch, and Alcohol Degydrogenase in Arabidopsis thaliana Exposed to N₂ Diluted Atmospheres. Plant and Cell Physiology, vol. 38(12), 1997, pp. 1354–1358.

Porterfield, D.M. and M.E. Musgrave: Oxytropism in Plant Roots. Gravitational and Space Biology Bulletin, vol. 10(1), 1996,pp. 23.

Porterfield, D.M. et al.: Spaceflight Exposure Effects on Transcription, Activity, and Localization of Alcohol Dehydrogenase in the Roots of Arabidopsis thaliana. Plant Physiology, vol. 113(3), Mar 1997, pp. 685–693.

Porterfield, D.M. and M.E. Musgrave: The Tropic Response of Plant Roots to Oxygen: Oxytropism in Pisum Sativum L. Planta, vol. 206(1), 1998, pp. 1–6.