Chlorpyrifos [BSA]

The application of organophosphorus pesticides (OPPs) increased gradually because of the rise in global food demand that triggered the agriculture sector to increase the production, leading to OPP residues in the surface water. This study elucidated the presence of OPPs and estimated its ecological risk in the riverine ecosystem of the urbanised Linggi River, Negeri Sembilan, Malaysia. The OPP concentration in surface water was determined using solid-phase extraction method and high-performance liquid chromatography coupled with diode array detection. Further, the ecological risk was estimated by using the risk quotient (RQ) method. The three OPPs, i.e. chlorpyrifos, diazinon, and quinalphos were detected with mean concentrations of 0.0275 mu g/L, 0.0328 mu g/L, and 0.0362 mu g/L, respectively. The OPPs were at high risk (in general and worst cases) under acute exposure. The estimated risk of diazinon was observed as medium for general (RQ(m) = 0.5857) and high for worst cases (RQ(ex) = 4.4678). Notably, the estimated risk for chlorpyrifos was high for both general and worst cases (RQ(m) = 1.9643 and RQ(ex) = 11.5643) towards the aquatic ecosystem of the Linggi River. Chronic risk of quinalphos remains unknown because of the absence of toxicity endpoints. This study presented clear knowledge regarding OPP contamination and possible risk for aquatic ecosystems. Hence, OPPs should be listed as one of the main priority contaminants in pesticide mitigation management in the future.

Inappropriate application of pesticides often triggers molecular alterations in crops, which inadvertently disturbs metabolites and finally affects crop quality. Therefore, understanding the mechanism of action of pesticides on crops is essential for evaluating the potential environmental impact of pesticides. Our findings indicated that three typical pesticides, including herbicide butachlor, insecticide chlorpyrifos, and fungicide tricyclazole, induced the expression regulation of different key genes, exhibiting considerable distinction on metabolic responses in rice (Oryza sativa L.). Butachlor mainly affected five carbohydrate metabolism pathways (38.5%), and more than 48.0% of differentially expressed genes (DEGs) were involved in the starch and sucrose metabolism as well as photosynthesis, thereby disturbing the distribution of starch-sucrose. Chlorpyrifos dramatically affected six amino acid metabolism pathways (60.0%), and key DEGs mainly enriched in the aspartate and glutamate metabolism, inducing an increase in free amino acid contents (up to 29.02% of the control) and degradation of soluble proteins (down to 48.72% of the control). Tricyclazole remarkably affected six fatty acid metabolism pathways (53.9%) and significantly upregulated DEGs which primarily code oil-body membrane proteins, which resulted in the decline of saturated fatty acids (palmitic acid and stearic acid) and the increase of unsaturated fatty acids (linolenic acid and octadecadienoic acid). These findings provide a molecular-scale perspective on the response of crops to pesticides.