Antioxidant activity of heme oxygenase 1 in Brassica juncea (L.) Czern. (Indian mustard) under salt stress

Antioxidant enzymes play a protective role in plants under oxidative stress. The present study explores the role of antioxidant system heme oxygenase1 (HO1) in Brassica juncea (L.) Czern. in salt stress conditions. B. juncea seedlings were treated with different NaCl concentrations (0-200 mM) for 5 days. Salt stress elicited the highest response at 150 mM NaCl concentration; at this level, gene expression of HO1 was also upregulated. Apart from HO1, ascorbate peroxidase (APX), peroxidase (POD), and glutathione reductase (GR) also showed their highest activity at 150 mM NaCl concentration. The study shows that HO1 is indispensable in B. juncea for overcoming the oxidative stress caused by salinity. Understanding the intricacy of the defense network, including HO1, against salt stress will be useful for future research into developing salt-tolerant varieties.