Effects of simulated microgravity on characteristics of photosynthesis in plant seedling.
OBJECTIVE
To study the effects of simulated microgravity on the characteristics of photosynthesis in some plant seedlings.


METHODS
Plant samples were treated on a 1 pi clinostat rotated at 2 gamma/min for 120 h. Then chlorophyll absorption and chlorophyll fast fluorescence induction kinetics were determined.


RESULTS
After treatment on the clinostat: 1) there were some increase in height and number of leaves per plant; 2) the strawberry seedlings contained 47.5% less chlorophyll and the carnation seedlings contained 4.3% more; 3) there was no change in position of the main absorption peaks of chlorophyll in both seedlings after the rotation, but their intensity was increased; 4) there were significant increase in the parameters of fluorescence induction kinetics in the leaves of both seedlings: there was an increase in Fv/Fo, Fv/Fm and T1/2, except CA/Fo; 5) there were some differences in excitation energy distribution between the two photosystems in the chloroplasts of control and treated samples.


CONCLUSIONS
Simulated microgravity does not have a significant effect on normal photosynthetic function in chloroplasts, so plant seedlings can grow up normally under microgravity.
Zhao
Qi
Q
Dept of Biology, Capital Normal University, Beijing. zhaoqi@mail.cnu.edu.cn
Li
Jun
J
Liu
Min
M
D002734:Chlorophyll / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism / Q000502:physiology; D029749:Dianthus / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D005453:Fluorescence; D005638:Fruit / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D006112:Gravitation; D045342:Light-Harvesting Protein Complexes; D010788:Photosynthesis / Q000502:physiology*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism*; D018520:Plant Shoots / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D027824:Rosaceae / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D012399:Rotation; D018474:Weightlessness Simulation
D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D002734:Chlorophyll