Impact of dietary phytochemicals and acaricide exposition on longevity and stimulation of detoxification mechanisms in Apis mellifera.

MITTON G; QUINTANA S; DE PIANO F; BRASESCO C; VILLALBA A; RUFFINENGO S; MAGGI M

Congreso; Reunión Conjunta de las Sociedades de Biociencias.; 2017

Recent studies have reported how pesticides impact on bees,affecting their behavior and survival. The main pollutants in beecolonies are due to chemical control of Varroa destructor, an ectoparasitemite of Apis mellifera. It has been shown that the nutritionalquality of A. mellifera diet appears to play an essential rolein honey bee health, particularly in the presence of pesticides. Inthis work, we examined the effect of phytochemicals (p-coumaricacid, indole-3-acetic acid and gibberellic acid) in lifespan of honeybees. Besides, we evaluated if administration of phytochemicals inthe diet increases the tolerance of bees to a synthetic acaricide, bystimulation of detoxification mechanisms. We conducted a series oflongevity assays with nurse bees fed with sugar syrup in the presenceor absence of p-coumaric, indole-3-acetic acid and gibberellicacid. Then, bees were exposed to DL50 of fluvalinate topically.We further explored if administration of indole-3-acetic acid in thediet can impact the expression of mRNA of genes involved in detoxificationpathways. Indole-3-acetic acid enhanced tolerance offluvalinate (log-rank: 3.823; p≤0.05); p-coumaric acid had a similareffect, although of reduced magnitude (log-rank: 2,433; p≥0.05) andgibberellic acid did not produce a significant result. mRNA expressionof cytochrome P450 6AS4 and carboxylesterase genes wasupregulated in bees fed with indole-3-acetic acid diet. Although, inbees with indole-3-acetic acid diet exposed to fluvalinate, the expressionof these genes was lower than in not exposed bees. Theexpression of cytochrome P450 9Q3 was downregulated in bees fedwith indole-3-acetic acid diet. Our results underscore the importanceof phytochemicals naturally present in nectar and pollen, and theirinfluence in honey bee longevity and pesticide stress.