Biochemical approach to the action of pesticides on Cucumis sativus in various stages of development

Romică CREȚU; Gabriel MURARIU

Romică CREȚU 1Department of Chemistry, Physics and Environment, Faculty of Sciences and Environment, “Dunarea de Jos” University of Galati Romania
Gabriel MURARIU Department of Chemistry, Physics and Environment, Faculty of Sciences and Environment, “Dunarea de Jos” University of Galati Romania, ”Vasile Alecsandri” University of Bacau, Romania

Keywords: insecticide, fungicide, peroxidase, polyphenoloxidases, plant pollution

Abstract

The use of pesticides has become a major environmental problem against the background of the intensification of agriculture. Thus, this economic sector of major importance worldwide has become a source of soil and plant pollution. Recent specialized studies show that pesticides can easily reach cultivated plants. In this situation, pesticides can have direct negative effects, accumulating in their tissues and acting enzymatically.

In this context, the aim of this study was to evaluate by spectrophotometric techniques the enzymatic changes that occur in Cucumis Sativus, as a result of its treatment with Dithane M45, Topsin 70 WDG and Mospilan 20 SG.

The monitoring of biochemical characteristics of the analyzed samples showed that, after pesticides were added, all the physico-chemical and biochemical characteristics of the Cucumis Sativus changed. Thus, the peroxidase activity monitoring showed that it varied from 75.1±0.18 enzymatic units after the first determination (seedling phase of plants) to 81.7±0.84 enzymatic units after three weeks from planting. Finally, the peroxidase activity was 75±0.42 enzymatic units to the maturity phase of the plants. Also, the results indicated that the activity of polyphenoxidases increases throughout this study (to 35.9±0.74 enzymatic units) because the antioxidant defense mechanism of plant cells has been activated. In all the analysed situations, research indicated notable differences from the behaviour of the control plants.

This study should be followed by future research on the response of the soil microbial community through their enzymatic system to the cumulative action of pesticides.