Abstract: The present study was aimed to investigate the role of NO in iron homeostasis and to evaluate the ability of NO to cope with iron deficiency or toxicity symptoms in two wheat (Triticum vulgaris L. Sids-1 and Gimmieza-7) cultivars. Seeds were germinated and grown in vermiculite watered with nutrient solution. Iron was supplied in different concentrations (zero, 20, 40, 80 and 160 μM) as Fe-EDTA. Sodium Nitro-Prusside (SNP) was used as NO donors in a 100 μM concentration and 100 μM Methylene Blue (MB) was used as NO scavengers. The solutions were supplied to plants by irrigation once a week included in the nutrient solution. The results revealed that NO plays a significant role in enhancing the availability of iron in iron-deficient conditions. It also ameliorates the adverse effect of excess iron in the two cultivars under investigation by increasing the activities of catalase and ascorbic acid peroxidase as well as NO concentrations and decreasing lipid peroxidation and protein degradation. Moreover, NO declined iron stress-induced chlorosis symptoms by increasing Chl. a+b concentration. NO was found to affect Chl. a+b content by enhancement of the conversion of Mg-protoporphyrin to pchlide and subsequently to chlorophyll. The role of NO was approved by using NO scavenger (MB) which reverses all NO effects when applied.