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. | Turkish Journal of Biology Turk J Biol (2015) 39: 540-549 © TÜBİTAK doi: Research Article Antioxidant activity of heme oxygenase 1 in Brassica juncea (L.) Czern. (Indian mustard) under salt stress 1 1 2 1, Khushbu VERMA , Shubham DIXIT , Gyan Singh SHEKHAWAT , Afroz ALAM * Department of Bioscience and Biotechnology, Banasthali University, Banasthali, Rajasthan, India 2 Department of Botany, JNV University, Jodhpur, Rajasthan, India 1 Received: Accepted/Published Online: Printed: Abstract: 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. Key words: Abiotic stress, antioxidant, Brassica juncea, heme oxygenase, salt stress 1. Introduction Abiotic stress is a global agricultural issue that limits plant growth and yield. Amongst abiotic stresses, salt stress leads to significant crop losses worldwide (Greenway and Munns, 1980). Although natural salts are present in soil, their increased concentration affects plant growth adversely. Rao et al. (2008) reported that salinity affects about 932 million hectares of land globally. In plant cells under salt stress, Na+
