Pesticide-induced oxidative stress and antioxidant responses in tomato (Solanum lycopersicum) seedlings

Abstract

Excessive use of pesticides can adversely affect the growth of non-target host plants in different ways. Pesticide-induced stress can affect non-target plants through elevated levels of reactive oxygen species (ROS) responsible for detrimental effects on cell metabolism, biochemical and other physiological activities. In response to oxidative stress, plant activates antioxidant defense system consisting of both enzymatic and non-enzymatic components. In the present investigation, three commonly used pesticides, emamectin benzoate, alpha-cypermethrin and imidacloprid, were assessed for causing oxidative stress in tomato. The oxidative damage induced by these pesticides at five different concentrations i.e. 1/4X, 1/2X, recommended application dose (X), 2X and 4X in the root and shoot tissues of tomato plant/seedlings were evaluated. Following pesticide exposure for 35 days, cell viability, cell injury, total soluble sugar (TSS) and total soluble proteins (TSP) were measured. Antioxidant activities were estimated by measuring activity levels of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) peroxidase (POD), ascorbate peroxidase (APX) and proline. Hydrogen peroxide (HO) levels were analysed as ROS, lipid peroxidation was measured in term of thiobarbituric acid reactive substances (TBARS) as membrane damage caused by ROS was also assessed. Analysis of the data revealed that pesticides application at higher concentrations significantly elevated ROS levels and caused membrane damage by the formation of TBARS, increased cell injury and reduced cell viability both in root and shoot tissues compared with non-treated plants. Moreover, a gradual decrease in the levels of TSS and TSP was observed in plants subjected to increasing doses of pesticides. To cope with pesticide-induced oxidative stress, a significant increase in levels of antioxidants was observed in the plants exposed to higher doses of pesticides. Shoot tissues responded more drastically by producing higher levels of antioxidants as compared to root tissues indicating the direct exposure of shoots to foliar application of pesticides. Taken together, these results strongly suggested that the application of pesticides above the recommended dose can provoke the state of oxidative stress and can cause oxidative damages in non-target host plants.

Pesticide-Induced Physiological, Metabolic and Ultramorphological Alterations in Leaves of Young Maize Seedlings

“…Our results show that single and joint toxicity of both pesticides increased proline accumulation as compared to control. Similar results have been reported by Shakir et al [52] and Nasrabadi and Dhumal [48] in tomato and brinjal under various pesticide stresses, respectively. Total soluble proteins (TSP) also plays a protective role during stress in many plant species such as rice, wheat, maize and various dicots.…”

Toxicity of fungicides toPisum sativum: a study of oxidative damage, growth suppression, cellular death and morpho-anatomical changes

“…A similar increase in H 2 O 2 accumulation in pesticide-treated seedlings of S. lycopersicum has recently been recorded. 51 Reactive oxygen species (ROS) are yet another highly reactive molecule that can damage biomolecules, such as lipids, proteins and nucleic acids. 52 Reactive oxygen species is a combined term that comprises both oxygen radicals, such as ), that can be converted easily to into radicals.…”

Applications of SERS in the Detection of Stress-Related Substances

“…Pesticides and veterinary drugs are commonly used to resist pests and diseases or to adjust the growth of plants and animals. As a kind of abiotic stress, their extensive use leads to serious environmental pollution and disturbance of various physiological processes in plants and animals [ 68 ]. Traditional chromatographic analysis for the detection of pesticides and veterinary drug residues are sensitive, accurate and reliable [ 69 ].…”