Exogenous Nitric Oxide Confers Tolerance to Cr(VI) in Maize (Zea mays L.) Seedlings by Modulating Endogenous Oxido-Nitrosative Events

The use of exogenous compounds such as ‘gasotransmitter’ molecules is a well-established agronomic strategy to improve the crop tolerance environmental stresses. In this current work, when Cr (200 µM) was combined with nitric oxide (NO) generator sodium nitroprusside SNP, 500 there suppression metal-induced alterations in embryo growth. Exogenous NO produced by SNP reduced accumulation toxic hydrogen peroxide and methylglyoxal stress-linked proline Cr-treated seedlings. Chromium increased thiol S-nitrosothiol levels but restored control spite competing reaction leading increase S-nitrosoglutathione content. However, added complexity indicated addition arginine analogue N (ω)-nitro-L-arginine methyl ester (L-NAME, germinating medium suppress endogenous production. This suppressed production superoxide dismutase (SOD) not enhanced + L-NAME treatments. addition, significantly decreased content spermidine spermine epicotyls compared treatment alone. Similarly, exposure both radicles epicotyls. important polyamines have been suggested route for Thus, our observations suggest that mitigates Cr-induced damage confers seedling through NADPH oxidase activity GSNO contents. may act prevent an excess peroxide. reduction polyamine mediated cellular generation could also promote viability under stress.