Physiological response of rapeseed (Brassica napus) to the insecticide imidacloprid

The widespread and indiscriminate application of insecticides within agricultural systems results in phytotoxic effects on non-target crops. Furthermore, the processes by which plants adapt and develop resistance to these agricultural chemicals are still not fully understood. This study provided a detailed analysis of the antioxidant enzyme responses, growth, photosynthetic activity, and pigment content under insecticide imidacloprid exposure on rapeseed (Brassica napus L.) plants to shed light on this issue. It has been observed that imidacloprid causes phytotoxicity in rapeseed, especially at high concentrations. The insecticide significantly affected growth parameters, pigment amounts, Fv/Fm ratio, H₂O₂ (hydrogen peroxide) and MDA (malondialdehyde) amount, and some antioxidant (APX-ascorbate peroxidase, CAT-catalase, DHAR-dehydroascorbate reductase, GPOD-guaiacol peroxidase, GR-glutathione reductase, SOD-superoxide dismutase) enzyme activities. These findings indicate that plants can adapt their physiological processes, such as enhancing antioxidant enzyme activities, modulating photosynthetic pigment composition, and adjusting osmoprotectant accumulation to withstand and endure insecticides up to a certain level. This research offers insights into how neonicotinoid insecticides affect plant health, linking directly to crop productivity and quality, as improved stress tolerance can lead to better growth performance, better photosynthetic activity, higher yield, lower reactive oxygen species levels, and enhanced nutritional value of the harvested produce.