Oxidative stress markers and antioxidant potential of wheat treated with phytohormones under salinity stress

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 acetic acid or salicylic acid salt tolerance in stressed wheat by significantly catalase, peroxidase, and ascorbate peroxidase, increased photosynthetic pigments and the accumulation of nontoxic metabolites (sugars, proteins, amino acid and free proline) as a protective adaptation mechanismin 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. 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.