Nitric Oxide as an Attenuator of Copper Toxicity in the concentration of Nutrients in maize Seedlings

Abstract

The maize crop is highlighted in the worldwide and Brazilian agribusiness, presenting itself as a raw material for both human and animal nutrition. Nitric oxide (NO) stands out as a signalling molecule playing a crucial role in plant responses to abiotic stresses as caused by heavy metals. Therefore, the objective of this work was to evaluate the effect of nitric oxide on the levels of macro and micronutrients, such as cationic magnesium, calcium, iron, copper, zinc and manganese. The copper bioaccumulation and translocation factor, in the initial growth of maize seedlings were subjected to copper toxicity. The seeds were soaked for 48 hours in Germitest paper using a solution containing sodium nitroprusside Na2[Fe(CN)5NO]2H2O as a donor of nitric oxide, sodium ferrocyanide Na4Fe (CN)6 as compensator and deionized water (control). The experiment was carried out in a 4 x 3 completely randomized factorial design with 12 treatments and 8 repetitions, totaling 96 trays containing 25 seeds per repetition. The results showed that the doses of nitric oxide were not sufficient to attenuate the copper toxicity, highlighting the metal accumulation in the roots. The doses of sodium nitroprusside and sodium ferrocyanide provided toxicity, changing the mineral balance in the mobilization of macro and cationic micronutrients and their translocation to the aerial part of K9606VIP3 maize seedlings in the initial growth.