Priming-mediated triggering of antioxidative response to induce drought tolerance in Maize (Zea mays L.)

Abstract

Drought is a well-known issue in plants and it occurs when plants do not receive enough water to meet their requirements. Hence it alters the metabolic process of the plant, consequently reducing the yield. To overcome the loss of yield under prevailing situations, triggering of the antioxidative defense system is required which can mitigate the impact of drought on plants. The priming chemicals KNO3, Mg(NO3)2 and GA3 were evaluated with hydro-priming to know the mitigative response of priming against drought-induced stress in Maize plants. The morpho-physiological and biochemical parameters were used to evaluate the impact of priming-mediated triggers on the antioxidative response. The results of this work indicate that leaf area index (LAI), crop growth rate (CGR, mg g-1 day-1), total chlorophyll, and chl‘a’ (mg g-1) were recorded maximum in T5 (Mg(NO3)2, 10 mM) while chl ‘b’ in T4 (Mg (NO3)2, 7 mM). The maximum Membrane Stability Index (MSI %) and Membrane Injury Index (MII%) were recorded in T5 and T0 (Control). The osmoregulatory compound proline content (µg g-1) and antioxidative enzyme catalase (nm H2O2 mg-1 min-1) were detected in significantly highest quantity in T3 (KNO3, 15 mM) while the least amount of malondialdehyde (MDA nm g-1) was found under the same treatment. The correlation studies amongst all the parameters reflected that MII % and MDA content (MDA nm g-1) negatively correlated with the remaining parameters studied. This study has reflected that out of all the sources of priming treatments, KNO3 in 15 mM and Mg(NO3)2 in 10 mM has the potential to trigger the antioxidative defense mechanism to mitigate the response of drought in Maize.