NaCl-INDUCED CHANGES IN OXYGEN EVOLVING ACTIVITY AND THYLAKOID MEMBRANE PATTERNS OF BARLEY PLANTS. ADAPTATION TO SALINITY
نویسندگان
چکیده
The effects of NaCl salinity on photosynthetic oxygen evolving activity and polypeptide membrane profiles were investigated in barley seedlings. High salinity (100mM NaCl) markedly reduced oxygen evolution in isolated thylakoids from NaCl-treated plants. Lower salt concentrations and stepwise (20–100mM NaCl) treatment of the seedlings had a lower effect on O2-producing reactions. Chloroplasts isolated from prolonged NaCl-treated plants showed enhanced ability to tolerate high (1M NaCl) concentration after in vitro incubation. We consider the observed stabilization in PSII oxygen-evolving activity as a result of adaptation to salinity. Protein patterns of thylakoid membranes on SDS-PAGE stained with Coomassie revealed that the relative amount of a number of polypeptides were altered when barley plants were grown on NaCl solutions. The results are discussed as an effect of prolonged NaCl application on the photochemical activity determined by some structural alterations in biomembranes that seems to play a specific role in the adaptive process.
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