Effect of the simulated weightlessness (clinorotation) on a photosynthetic apparatus of barley plants (HORDEUM VULGARE L.)

1Volovik, OI, 2Sytnik, SK, Topchiy, NN
1Institute of Plant Physiology and Genetics, NAS of Ukraine, Kyiv, Ukraine
2M.G. Kholodny Institute of Botany of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
Kosm. nauka tehnol. 2004, 10 ;(5-6):215-217
Publication Language: Russian
The effect of microgravitation (simulated by clinorotation) on the organization and functioning of chloroplasts, isolated from barley plants, is studied with the use SDS-electrophoresis, spectrophoto-metric and polarography methods. The relative content of monomeric forms of light harvesting complex of photosystem II (LHCII) increases at the expense of its oligomeric forms under clinorotation conditions. The decrease of the portion of the entire complex of photosystem I (PSD as well as of the sum of the PSI complexes and the complex CPa (related to PSII) was observed in experimental variants. Clinorotation induced the decrease in PSI, PSII and full electron transport activity, and the extent of the reduction depended on the light intensity during plant growth. The ATP synthesis coupled with cyclic, noncyclic and linear electron transport was inhibited under the simulated microgravitation.

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