Ridvan Temizgul, Mahmut Kaplan, Rukiye Kara, Semih Yilmaz
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Sorghum, Salt stress, Antioxidant system, Enzyme activity, ROS.
The present study was conducted to determine salt response of grain sorghum (Sureno) plants through antioxidant defense enzymes and to determine their salt resistanceat biochemical level. Sorghum plants were grown in climate chambers for 15 days in 3 replications in Hoagland growth medium under different salt concentrations (0, 50, 100, 150, 200 mM). At the end of growing period, roots and leaves were separated and the effects of salt stress were assessed spectrophotometrically through antioxidant enzymes, chlorophyll and carotenes. Root CAT increased until 100 mM, SOD, APX and GST activities increased with increasing salt concentrations until 150 mM and then they all decreased. Increasing salt concentrations elevated MDA accumulation in sorghum roots. Leaf SOD and APX activities and proline contents increased until 150 mM and CAT, GR and GST activities increased until 100 mM and then they all decreased. Leaf MDA contents also increased with higher salt concentrations. However, increasing salt concentrations decreased chlorophyll contents at 100 mM, carotene contents increased until 150 mM and then decreased. Although ascending antioxidant enzyme activity improved salt resistance of sorghum plants, increasing concentrations were not found to be sufficient. Thus, further studies with higher concentrations should be carried out to elucidate the case.
