Clinorotation affects the state of photosynthetic membranes in Arabidopsis thaliana (L.) Heynh.

Photosynthesis is known to provide nearly all the carbon and chemical energy needed for plant growth, it depends on many environmental factors and alternates when these factors fluctuate. The degree of the chloroplast membrane system development can be, to a certain extent, an indicator of the organelles' photosynthetic activity. To-date, changes in chloroplast size and ultrastructure as well as starch and pigment content in leaf mesophyll cells in microgravity have been found in variety of the angiosperm species investigated in this respect. However, available data are very limited and contradictory. Taking into account the importance of studying the photosynthesis process to elucidate the possibilities of plant physiological adaptation in altered gravity that is the basis for working out the technologies of space planting in controlled ecological life-support systems, we conducted the investigations of ultrastructure and state of the photosynthetic apparatus in Arabidopsis thaliana leaf mesophyll cells at the different stages of plant development under clinorotation.