Effects of salinity on photosystem II activity and antioxidant enzymes
in two Türkish barley cultivars
Abstract
The antioxidant activity and photosynthetic efficiency of two Türkish
barley cultivars, Erginel-90 and Tokak 157/37, grown under 120 mM NaCl,
was studied. Photosynthetic and antioxidative changes were much more
significant after 7 days of salt treatment. The photosynthetic apparatus
of Tokak 157/37 was found to be more tolerant to salt stress as compared
with Erginel-90, probably due to higher antioxidant activity, lower H2O2
content and lower lipid peroxidation. After 7 days of salt treatment,
Erginel-90 showed high value of the rate of accumulation of closed
reaction centers (V/to) and dissipation energy flux per PSII reaction
center (DIo/RC) while it is not changed in Tokak 157/37 as compared to
control. SM, N, o, ETo/RC, SFIABS, o/(1-o), performance index
(PIABS), Ro and Ro were drastically lower than control in Erginel-90
under salt stress for 7 days, however, these parameters in Tokak 157/37
were very close to the values determined in control plants. Thus, on the
basis of our results on two barley cultivars, we recommend the use of
some JIP test parameters such as V/to, SM, N, SFIABS, PI, Ro, PI and
Ro for the detection of salt-induced changes and to test salt tolerance
degree in barley cultivars.