Effect of Fe Deficiency on Antioxidant System in Leaves of Three Flax Cultivars

Abstract

The potential role of antioxidant enzymes as well as antioxidant compounds in protecting plant from the deleterious effect of iron deficiency was examined in different flax Linum usitassimum L. cultivars. Three flax cultivars (Sakha 1, Sakha 2 and Giza 8) were grown in water culture with (Fe-sufficient plants, +Fe) or without (Fe-deficient plants,-Fe) iron supply for 40 days. The obtained results showed that, iron deficiency severely decreased dry weight and concentration of iron in all cultivars leaf tissue. Besides this, to verify whether iron deficiency could induce alteration in reactive oxygen species, high concentration of lipid peroxidation (TBARS) and H2O2 content in leaves of flax cultivars were detected under (-Fe) compared to (+Fe) treatments. Iron deficiency can also modulate the content of glutathione (GSH) level, which were significantly increased in Fe deficient treatment compared to Fe-sufficient treatment among cultivars. Activity of superoxide dismutase (SOD) was increased under deficient treatment. In contrast, significant differences were observed between cultivars in the activity of Fe containing enzymes such as ascorbate peroxidase (APX), peroxidase (POD) and catalase (CAT) that was greater under Fe sufficient treatment, suggesting higher amounts of physiological iron in leaf tissue of all cultivars. In addition, some changes in POD isoenzyme profile was detected under iron stress.These results suggested that, these antioxidant compounds are the key compounds to protect cell from oxidative injury.