Unveiling the Impact of Thiophanate-Methyl on Arthrospira platensis: Growth, Photosynthetic Pigments, Biomolecules, and Detoxification Enzyme Activities

• Published in: Frontiers in bioscience (Landmark. Print) 2023-10, Vol.28 (10), p.264-264
• Main Authors: Touzout, Nabil, Ainas, Mahfoud, Alloti, Rabia, Boussahoua, Chahinez, Douma, Aicha, Hassein-Bey, Amel Hind, Brara, Zahia, Tahraoui, Hichem, Zhang, Jie, Amrane, Abdeltif
• Format: Article
• Language: English
• Subjects: arthrospira platensis; Chemical engineering; Chemical Sciences; cyanobacteria; ecotoxicology; oxidative stress; thiophanate-methyl
• ISSN: 2768-6701; 2768-6698
• DOI: 10.31083/j.fbl2810264

BACKGROUNDThe intensive and injudicious use of pesticides in agriculture has emerged as a major concern due to its detrimental impact on aquatic ecosystems. However, the specific impact of broad-spectrum fungicides, such as Thiophanate-methyl (TM), on cyanobacteria remains a subject of ongoing research and debate.METHODSIn order to fill this knowledge gap, The present study aimed to comprehensively investigate the toxicological effects of TM (10-30 µg/L) on the growth, photosynthetic pigments, oxidative stress, and biochemical composition of the non-nitrogen-fixing cyanobacterium Arthrospira platensis.RESULTSOur findings unequivocally demonstrated that TM exposure significantly inhibited the growth of A. platensis. Moreover, the decrease in chlorophyll content indicated a pronounced negative impact on the photosynthetic system of A. platensis caused by TM exposure. Notably, TM induced oxidative stress in A. platensis, as substantiated by a significant increase in lipid peroxidation (MDA) within the culture. Furthermore, the intracellular generation of hydrogen peroxide (H2O2) exhibited a positive correlation with higher TM dosages, while the levels of vital antioxidant enzymes, such as catalase (CAT) and ascorbate peroxidase (APX), exhibited a discernible decrease. This suggests that TM compromises the antioxidant defense mechanisms of A. platensis. Additionally, TM was found to enhance the activity of a plethora of enzymes involved in the detoxification of pesticides, including peroxidase (POD) and glutathione-S-transferase (GST), thereby indicating a robust detoxification response by A. platensis. Interestingly, exposure to TM resulted in a general suppression of biocomponent production, such as total proteins and total carbohydrates, which exhibited a diminishing trend with increasing TM concentration. Conversely, the lipid content witnessed a significant increase, possibly as an adaptive response to TM-induced stress.CONCLUSIONSThese findings contribute to a deeper understanding of the ecological implications of pesticide usage and emphasize the urgent need for the adoption of sustainable and environmentally-friendly agricultural practices to safeguard aquatic ecosystems.