The effect of pesticides on the mtDNA integrity and bioenergetic properties of potato mitochondria

Potato (Solanum tuberosum L.) is one of the most common crops in the world, and it is very susceptible to a wide range of pests such as insects and fungi. The use of pesticides often results in the suppression of seed germination and plant growth, in particular, due to their effect on the respiratory chain of mitochondria. There are numerous studies of the effect of pesticides on animal mitochondria, but their interference with the electron transport in plant mitochondria is not well documented. We present the data showing that a number of pesticides inhibit electron flow, and other pesticides uncouple the respiratory chain. Among the studied pesticides engaging the alternative pathways of electron transport, dithianon led to an increase in the rate of H₂O₂ production but did not cause a strong increase in the amount of mtDNA damage as compared to other pesticides. In general, the main negative effect of the studied pesticides is manifested in a decrease of membrane potential with the maintenance of the rate of oxygen consumption and a low rate of H₂O₂ production. The mtDNA damage is caused mainly by pesticides belonging to the pyrethroid class and remains minor as compared to its damage in animals. Our data indicate that the respiratory chain of plant mitochondria is more resistant to pesticides as compared to animal mitochondria due to the presence of the alternative pathways of electron transport.