Ferritin induction by iron mediated oxidative stress and ABA in Vigna mungo (L.) hepper seedlings: Role of antioxidants and free radical scavengers

The iron storage protein ferritin acts as an antioxidant by sequestering ex cess iron, thereby limiting the availability of free excess iron and preven ting the generation of OH-type radicals. Oxidative stress and ABA mediate f erritin induction in maize whereas only oxidative stress operates in Arabid opsis. Iron mediates oxidative stress in Vigna mungo (L.) Hepper as reveale d by upregulation of activities of antioxidative enzymes and reduction of t he activity in the presence of antioxidants and free radical scavengers. Pr e-treatment of iron deficient de-rooted seedlings with free radical scaveng ers and antioxidants followed by co-treatment with ferric citrate inhibited ferritin induction. Pro-oxidant (H2O2) treatment resulted in induction of ferritin up to 2 mmol/L. ABA induced ferritin in a dose dependent manner. T hese results indicate that both iron mediated oxidative stress and ABA lead to ferritin induction. It was also observed that ferritin induction is spe cific for iron in comparison to other metals.