The Impact of Priming with Al2O3 Nanoparticles on Growth, Pigments, Osmolytes, and Antioxidant Enzymes of Egyptian Roselle (Hibiscus sabdariffa L.) Cultivar

Abstract

Lower concentrations of nanoparticles (NPs) could have positive effects on plants. In the present experiment, we tested the efficacy of seed priming Egyptian roselle cultivar with aluminum oxide nanoparticles (Al2O3 NPs). Plants grown with different concentrations (0.01, 0.05, 0.1, and 0.5%) of Al2O3 NPs-primed seeds showed varied responses. An increasing impact with 0.01% Al2O3 NPs was noticed on growth traits, such as fresh weight, dry weight, shoot length, root length, and leaf area, and physio-biochemical activities like chlorophyll a, chlorophyll b, carotenoid contents, soluble sugars, protein, amino acid, proline, and the activities of defense enzymes viz-superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX). Nevertheless, a decrease was noted in malondialdehyde (MDA) when plants were primed with 0.01% Al2O3 NPs. Seed priming with 0.05, 0.1, and 0.5% Al2O3 NPs caused the negative effects in the aforementioned parameters. The principal component analysis revealed significant correlations among the various studied parameters. Therefore, seed priming with Al2O3 NPs at 0.01% was expected to serve as an effective measure for inducing positive effect in Egyptian roselle cultivar.