Nitric oxide alleviates boron toxicity by reducing oxidative damage and growth inhibition in maize seedlings (Zea mays L.)

Abstract

Nitric Oxide (NO) is an important signal molecule modulating the plants responses to abiotic stresses. In this study the effects of exogenous NO as sodium nitroprusside (SNP) on boron (B)-induced oxidative damage and growth in maize (Zea mays L.) were investigated. The addition of B significantly reduced the growth of plants and increased the values of electrolyte leakage, malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents. SNP (100μM) that was applied to seeds before germination significantly increased plant height (respectively, 8 and 5%), fresh weight (respectively, 9 and 6%), and dry weight (respectively, 15 and 12%) of both 11 and 15 day old maize. Furthermore, the measured B-induced oxidative stress increased MDA, electrolyte leakage, (H2O2) content when compared to a supplementation of NO. SNP application also increased activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX). The results suggest that the increased NO, resulting from SNP application, improved the antioxidant capacity of maize plants against B-induced oxidative stress.