TITLE:
Effect of Salinity Stress on Antioxidant Defense System of Niger (Guizotia abyssinica Cass.)
AUTHORS:
Hemla Naik Kavya Naik, Varadahalli R. Devaraj
KEYWORDS:
Niger, Guizotia abyssinica, Salinity Stress, Antioxidants, Antioxidant Enzymes, Lipid Peroxidation
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.7 No.6,
April
29,
2016
ABSTRACT: Salinity is one of the
principal abiotic stresses that affect plant productivity by inducing osmotic
stress, which in turn, causes oxidative stress. Plants respond to this
oxidative stress by adjusting levels of antioxidants and associated components.
10-day old seedlings of Niger were evaluated for abiotic stress response in
terms of antioxidants and antioxidant enzymes over 72 h in presence of up to
500 mM NaCl in combination with CaCl2. Stress markers: H2O2,
lipid peroxidation, antioxidants; ASC and GSH and antioxidant enzymes such as
POX, APX and GR were significantly elevated, while CAT was reduced. The
response was concentration and time-dependent up to 300 mM NaCl and fluctuated
beyond. Metabolic enzymes β-amylase
and acid phosphatase exhibited moderate increase relative to controls. The
parameters indicated tolerance of the plants to salinity up to 300 mM over 48
h.