Oxaloacetic Acid

The ecological risks of pyraclostrobin (PY) in the environment have become an increasing concern, yet its chronic toxicity and mechanism to aquatic organisms remain unclear. This study employed histopathological, metabolomic, and transcriptomic analyses to investigate the chronic effects of environmental concentrations of PY and underlying potential toxic mechanism in adult zebrafish. The result showed that 0.24 and 2.4 μg/L PY induced liver damage in zebrafish after 21 d exposure, with 0.24 μg/L PY elicited more pronounced transcriptional and metabolic alterations across diverse pathways in zebrafish liver. Mechanistic analyses showed that PY exposure could decrease the transcription of genes involved in pyrimidine and purine metabolism, thereby disrupting nucleotide synthesis, while simultaneously down-regulating the expression of multiple genes related to DNA replication processes and DNA repair system. Furthermore, PY perturbed hepatic glucolipid metabolism, evidenced by glycerophospholipid accumulation and decreased levels of glucose, pyruvate, triglyceride, cholesterol, and carbohydrates. The reduction in carbohydrates involved in ABC transporters, as well as the disruption in Abcb5, Abcc1, Abcd2, Abcd3 or Abcc10 transcription, suggested that ABC transporters might mediate PY-induced metabolic dysfunction. These findings provided mechanistic insights into PY-induced hepatotoxic effects in zebrafish, highlighting the need to address the chronic toxicity and ecological risks of environmental concentrations of PY for aquatic organisms.

This study investigated the metabolic changes occurring during the ripening of Campomanesia pubescens fruits using metabolomics and proteomics approaches. Two alkaloids and nine phenolic compounds were identified, with emphasis on trigonelline and gallic acid. Proteomic analysis revealed 940 proteins, of which 452 showed differential expression, reflecting physiological changes, such as the reduced expression of ribulose-1,5-bisphosphate carboxylase/oxygenase, indicating low photosynthetic activity and the transition from chloroplasts to chromoplasts. The intensification of glycolysis was suggested by the increased expression of phosphoglycerate kinase and fructose-bisphosphate aldolase. The activation of enzymes of the phenolic compound pathway, such as phenylalanine ammonia-lyase and O-methyltransferase, indicated the accumulation of secondary metabolites essential for fruit defense and nutritional quality. The expression of enzymes in the ethylene pathway, such as SAM synthase, suggested their role in gabiroba ripening. The results highlight the interaction of metabolic pathways during fruit ripening.