Nitric Oxide-Mediated Modulation of Functional Iron Status in Iron-Deficient Maize Plants

Abstract

Nitric oxide is reported to alleviate Fe-deficiency effects, possibly by enhancing the functional Fe status of plants. Study describes changes in leaf tissue Fe status and consequent modulation of oxidative stress and antioxidant defense in Fe-deficient maize (Zea mays L.) plants supplied with NO. Supply of sodium nitroprusside (SNP), but not of sodium ferrocyanide (SF), caused regreening of leaves, syntheses of chlorophylls and carotenoids and increased activities of hydrogen peroxide-scavenging heme-Fe enzymes and lipid peroxidation, decreased SOD activity and hydrogen peroxide concentration. Though SNP or SF appears to donate Fe and increase leaf active Fe, the later did not induce increases in chlorophyll and carotenoids, and therefore NO appears to have a role in Fe nutrition irrespective of total or active Fe status of plants.