Silicon and Nitric Oxide-Mediated Regulation of Growth Attributes, Metabolites and Antioxidant Defense System of Radish ( L.) under Arsenic Stress

Arsenic (As) contaminated food chains have emerged as a serious public concern for humans and animals are known to affect the cultivation of edible crops throughout world. Therefore, present study was designed investigate individual well combined effects exogenous silicon (Si) sodium nitroprusside (SNP), nitric oxide (NO) donor, on plant growth, metabolites, antioxidant defense systems radish (Raphanus sativus L.) plants under three different concentrations As stress, i.e., 0.3, 0.5, 0.7 mM in pot experiment. The results showed that stress reduced growth parameters by increasing level oxidative markers, malondialdehyde hydrogen peroxide. However, foliar application Si (2 mM) pretreatment with SNP (100 µM) alone combination improved parameters, root length, fresh dry weight stress. Furthermore, also protein, metabolites contents (flavonoids, phenolic anthocyanin). Activities antioxidative enzymes such catalase (CAT), ascorbate peroxidase (APX), guaiacol (POD), polyphenol oxidase (PPO), content non-enzymatic antioxidants (glutathione ascorbic acid) decreased In most radish, III concentration maximum reduction, compared I II concentrations. NO significantly alleviated As-mediated content. Enhancement activities CAT, APX, POD PPO were recorded. Contents glutathione acid enhanced response co-application Results obtained more pronounced when applied their application. short, current highlights synergistically regulate through lowering upregulating content, activity plants.