Responses of grape (Vitis vinifera L.) antioxidant system to salinity

Salinity is one of the important environmental factors that limit plant growth and product. Grapes are classified as salt sensitive plants. This paper attempts to evaluate the salinity effects on membrane lipid peroxidation، antioxidant components and antioxidative enzymes activity in four grape genotypes (Vitis vinifera L.، Gharashani، LaaleBidaneh، Sachagh and Shahroodi) that commonly grow in the regions around Urmia Salt Lake. We came to the conclusion that malondialdehyde content and antioxidative enzymes activity increased significantly (P<0. 05) in roots and leaves of all these genotypes. Gharashani and LaaleBidaneh genotypes showed higher antioxidative enzymes activity and lower membrane lipid peroxidation. Also، salinity had a significant effect on the accumulation of total phenolics content and phenylalanine ammonia lyase activity in all genotypes. Gharashani genotype showed the highest total phenols and PAL activity. There was a significant positive correlation among antioxidant enzymes activity، total phenolics content and PAL activity in leaves of all genotypes. It seems that Gharashani and LaaleBidaneh genotypes have a better antioxidant system compared with others and show higher efficiency for salinity tolerance.