Exogenous Application of Salicylic Acid to Alleviate Glyphosate Stress in Solanum lycopersicum

ABSTARACT

Pesticides have nontarget toxicity and affect growth and yield of Tomato (Solanum lycopersicum L.). Salicylic acid (SA) acts a as plant growth regulator that supports plant defense systems. Activity of SA was studied to determine whether it reduced glyphosate toxicity and benefited growth and yield of tomato plants. Glyphosate at 0.25 mM and SA at 1 mM were applied to tomato seedlings at 20 days after sowing. Glyphosate decreased shoot and root length and fresh and dry weight of seedlings. Carotenoids, chlorophylls, and protein contents and activity of nitrate reductase were inhibited. Accumulation of sugar, proline content, and oxidative indices (H₂O₂, ion leakage, lipid peroxidation) was enhanced due to treatment with glyphosate. The antioxidant enzymes superoxide dismutase and guaiacol peroxidase increased; activities of catalase and ascorbate peroxidase decreased. Anthocyanin content declined and phenyl ammonia lyase enzyme activity increased. Pigment content and activities of antioxidant enzymes increased up to the level of the control. The level of glyphosate used caused phytotoxicity to tomato. Salicylic acid has the potential to overcome adverse effects caused by glyphosate if application is done before exposure.

Keywords:

• Solanum lycopersicum
• growth
• herbicide
• oxidative stress
• tomato

Funding

The authors thank the University Grant Commission, New Delhi, and the University of Allahabad, Allahabad, India, for providing financial assistance to Himani Singh.

Additional information

Funding

The authors thank the University Grant Commission, New Delhi, and the University of Allahabad, Allahabad, India, for providing financial assistance to Himani Singh.