Journal of Stress Physiology & Biochemistry, Vol. 7, No. 4,
2011, pp. 250- 267. ISSN 1997-0838
Original Text Copyright (cc) 2011 by Barakat
Oxidative stress markers and antioxidant potential of wheat treated with phytohormones under salinity stress
Nasser A.M. Barakat
Minia University, Faculty of Science, Botany and Microbiology Department, El-Minia 61519, Egypt.
*E-mail: nasserbarakat2003@yahoo.com
Received September 24, 2011
The interactive effects 0.5
mM indole acetic acid or 0.1 mM of salicylic acid as shoot spraying on
NaCl wheat stressed plant organs (spike, shoot and root) grown in pot
experiment under different salinity levels (0, 50, 100, 150 and 200 mM
NaCl) were studied. The antioxidant enzymes as catalase, peroxidase and
ascorbate peroxidase, photosynthetic pigments, reducing sugar,
proteins, amino acids, and proline contents in spike, shoot and root of
salinity stressed plants were the most affected parameters specially at
high salinity levels (150-200 mM NaCl).Treatments with 0.5 mM indole
acetic acid or 0.1 mM of salicylic acid as shoot spraying on NaCl wheat
stressed plant organs mitigated the harmful effect of NaCl. To conclude
the phytohormone indole acetic acid or salicylic acid improved salt
tolerance in stressed wheat by significantly activated catalase,
peroxidase, and ascorbate peroxidase, increased photosynthetic pigments
and enhancing the accumulation of nontoxic metabolites (sugars,
proteins, amino acid and free proline) as a protective adaptation
mechanism in different wheat organs. However, the magnitude of increase
was more pronounced in salicylic acid treated plants than in indole
acetic acid treated ones, and the spike was more accumulator organ of
non toxic metabolites compared to shoot and root. Thus salicylic acid
and/or indole acetic acid treatments prevents the deleterious effects
of salinity stressed wheat and could be adopted as a potential growth
regulator or antioxidant to improve growth particularly under moderate
NaCl salinity levels, wheat plant respond positively to SA foliar
application than IAA application.
Key words: Antioxidant enzymes; photosynthetic pigments; metabolic
processes; indole acetic acid; salicylic acid; salinity; Triticum.
