Abstract
Paraquat (PQ) causes oxidative stress, the main source of damage in plants subjected to adverse environmental factors. Sodium nitroprusside (SNP), a signaling molecule, alleviates oxidative damage. The present study was carried out to investigate the role of exogenous SNP in the amelioration of PQ-mediated oxidative stress effects on Eruca sativa plantlets cultured in MS basal media. Firstly, MS medium supplemented with 6-BA was found to be the best basal medium for seed germination. Then, a rapid micropropagation protocol was designed to produce E. sativa plantlets by using nodal segments as explants, and 0.25 mg/L 6-BA in combination with 0.1 mg/L IBA was found to be the most favorable for shoot proliferation of E. sativa. Four weeks old plants were applied with or without SNP (100 μM) and exposed to oxidative stress induced by 2.5 μM PQ. The SNP application decreased membrane damage, hydrogen peroxide, and proline contents, and increased relative water, pigments, ascorbate and total phenolic contents, and some antioxidant enzyme activities in seedlings under PQ stress compared to PQ stress alone. These results suggested that exogenous SNP could protect E. sativa plantlets propagated in vitro with PQ stress through modulation of proline and phenolics biosynthesis and antioxidant defense system.