title: Evaluation of the toxicity of fungicides to flight muscle mitochondria of bumblebee (Bombus terrestris L.).
abstract: Insects pollinate 75% of crops used for human consumption. Over the last decade, a substantial reduction in the abundance of pollinating insects has been recorded and recognized as a severe matter for food supply security. Many of the important food crops destined for human consumption are grown in greenhouses. A unique feature of greenhouse agriculture is the extensive use of fungicides to curb multiple fungal infections. The most widely used pollinating insects in greenhouses are commercially reared bumblebees. However, there is no data regarding the toxicity of fungicides to bumblebee mitochondria. To fill this gap in knowledge, we examined the effects of 16 widely used fungicides on the energetics of the flight muscles mitochondria of Bombus terrestris. We found that diniconazole and fludioxonil uncoupled the respiration of mitochondria; dithianon and difenoconazole inhibited it. By analyzing the action of these inhibitors on mitochondrial respiration and generation of reactive oxygen species, we concluded that difenoconazole inhibited electron transport at the level of Complex I and glycerol-3-phosphate dehydrogenase. Dithianon strongly inhibited succinate dehydrogenase and glycerol-3-phosphate dehydrogenase. It also strongly inhibited mitochondrial oxidation of NAD-linked substrates or glycerol 3-phosphate, but it had no effect on the enzymatic activity of Complex I. It may be suggested that dithianon inhibits electron transport downstream of Complex I, likely at multiply sites.
authors.affiliation: Voronezh State University, Voronezh, University sq. 1, 394006 Voronezh, Russia. Electronic address: syromyatnikov@bio.vsu.ru.
authors.forename: Mikhail Y
authors.initials: MY
authors.lastname: Syromyatnikov
authors.affiliation: Voronezh State University, Voronezh, University sq. 1, 394006 Voronezh, Russia.
authors.forename: Anastasia V
authors.initials: AV
authors.lastname: Kokina
authors.affiliation: Voronezh State University, Voronezh, University sq. 1, 394006 Voronezh, Russia.
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Lopatin
authors.affiliation: Weill Medical College Cornell University, New York, 525 E 68th street, A501, NY 10065, USA.
authors.forename: Anatoly A
authors.initials: AA
authors.lastname: Starkov
authors.affiliation: Voronezh State University, Voronezh, University sq. 1, 394006 Voronezh, Russia.
authors.forename: Vasily N
authors.initials: VN
authors.lastname: Popov
mesh_terms: D000818:Animals; D001516:Bees; D004579:Electron Transport / Q000187:drug effects; D042967:Electron Transport Complex I / Q000378:metabolism; D005659:Fungicides, Industrial / Q000633:toxicity*; D005993:Glycerolphosphate Dehydrogenase / Q000037:antagonists & inhibitors / Q000378:metabolism; D005994:Glycerophosphates / Q000378:metabolism; D019476:Insect Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008931:Mitochondria, Muscle / Q000187:drug effects* / Q000378:metabolism; D009245:NADH Dehydrogenase / Q000037:antagonists & inhibitors / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013385:Succinate Dehydrogenase / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D005659:Fungicides, Industrial; D005994:Glycerophosphates; D019476:Insect Proteins; D017382:Reactive Oxygen Species; C029620:alpha-glycerophosphoric acid; D005993:Glycerolphosphate Dehydrogenase; D013385:Succinate Dehydrogenase; D009245:NADH Dehydrogenase; D042967:Electron Transport Complex I
keywords: Bombus terrestris; Fungicides; Membrane potential; Mitochondria; Reactive oxygen species; Respiration