XVI International Botanical Congess

The comparative analysis of wheat seedlings (Triticum aestivum) chlorophyll-protein complexes (CPC) state within different time (from 1 to 24 h) of water deficit caused by NaCI and polyethyleneglycol (PEG), creating both osmotic pressure equal to -14.5 bar for differentiation salt toxic and water deficit effect. The thylakoids CPC have been shown to be more sensitive to Na and CI ions action during the first hours of stress. It is expressed by changes in subunit composition of complexes, concerned to reaction centers (RC) of PS1 and PS2, namely by appearance and increase of monomeric subunits part. To 24 hours of stress, the PS1RC and LHC (light harvesting) complexes are indentical to control but RC of PS2 are dissociated. In the case of PEG action the dissociation of PS2RC complexes was observed during two hours of incubation. After 24 h of PEG effect, the subunit composition of PS2RC was not affected while was reduced quantitavely to some degree. The primary toxic effect Na and CI ions on the CPC state was shown. This conclusion is in agreement with protein and fluorescence analysis of complexes.