Rice Science ›› 2018, Vol. 25 ›› Issue (4): 185-196.DOI: 10.1016/j.rsci.2018.06.002

• Orginal Article • Previous Articles     Next Articles

Antioxidant Protection Mechanisms Reveal Significant Response in Drought-Induced Oxidative Stress in Some Traditional Rice of Assam, India

Nahar Shamsun1, R. Vemireddy Lakshminarayana2, Sahoo Lingaraj3, Tanti Bhaben1()   

  1. 1Department of Botany, Gauhati University, Guwahati 781014, Assam, India
    2Regional Agricultural Researc Station, Acharya N. G. Ranga Agricultural University, Tirupati 517502, India
    3Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
  • Received:2017-12-30 Accepted:2018-02-27 Online:2018-06-20 Published:2018-04-10

Abstract:

Drought tolerance levels and antioxidant protection mechanisms were evaluated for 21 traditional rice varieties of Assam, India, along with Sahbhagi Dhan (drought tolerant) and IR64 (drought sensitive) as controls. Drought was imposed in hydroponic culture with polyethylene glycol 6000 (PEG6000) that was initially standardized with different concentrations. All the rice varieties showed apparent decreases in growth characteristics under drought stress (initially at 15% for 7 d followed by 20% PEG6000 for 7 d in Yoshida medium). On the basis of standard evaluation score (SES), eight rice varieties showed high drought tolerance which were carried forward for further biochemical analyses. Based on different morpho- physiological parameters, SN03 (Bora), SN04 (Prosad Bhog), SN05 (Kola Joha), SN06 (Helash Bora), SN08 (Salihoi Bao), SN12 (Kola Amona), SN20 (Ronga Bora) and SN21 (Sok-Bonglong) were identified as promising drought tolerant varieties. The non-enzymatic antioxidants activities viz., glutathione, ascorbate and enzymatic antioxidant activities such as superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPX), ascorbate peroxidase (APX), glutathione reductase (GR) in shoots and roots of all the selected varieties revealed significant level of protection mechanisms as compared with controls. Enhancement in activities of the overall antioxidant enzymes including SOD, GPX, CAT, GR and APX under drought stress reflects their role in the adaptation process under water stress.

Key words: drought stress, traditional rice, standard evaluation score, antioxidants protection mechanism, antioxidant enzyme