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ASTROCULTURE (TM) root metabolism and cytochemical analysis
D M Porterfield1, D J Barta, D W Ming
1Dept. of Plant Pathology & Crop Physiology, Louisiana State University Agriculture Center, Baton Rouge, USA.
Advances in Space Research : the Official Journal of the Committee on Space Research (COSPAR)
|September 7, 2001
Summary
Spaceflight increased alcohol dehydrogenase (ADH) activity in plant roots, indicating hypoxic conditions. This highlights the need for adequate root zone oxygenation in space-based plant growth systems.
Area of Science:
- Plant Physiology
- Biochemistry
- Space Biology
Background:
- Root system physiology relies on oxygen for respiration and nutrient/water acquisition.
- Hypoxia (low oxygen) can impair plant physiological and biochemical functions.
- Alcohol dehydrogenase (ADH) activity is a sensitive indicator of hypoxic stress in plants.
Purpose of the Study:
- To measure oxygen availability in the root zone of plants grown in Astroculture™ hardware.
- To assess the impact of spaceflight on alcohol dehydrogenase (ADH) activity in plant roots.
- To investigate the localization of ADH enzyme within root tissues under spaceflight conditions.
Main Methods:
- Biochemical assays were performed to measure ADH activity in spaceflight and control plant roots.
- Cytochemical staining was used to determine the tissue localization of ADH.
- Dwarf wheat and Brassica species were used for spaceflight and ground control experiments.
Main Results:
- Spaceflight exposure significantly increased ADH activity in dwarf wheat roots (248-304%) and Brassica (334-579%) compared to controls.
- Cytochemical analysis showed no significant differences in ADH tissue localization across treatments.
- Elevated ADH activity suggests hypoxic conditions developed in the root zone during spaceflight.
Conclusions:
- Spaceflight induces hypoxic stress in plant root systems, evidenced by increased ADH activity.
- The findings underscore the critical importance of root zone oxygenation for spaceflight plant cultivation systems.
- This study confirms previous observations of an ADH response to spaceflight.