Supplementary Dataset from Pollen nutrition fosters honeybee tolerance to pesticides

A reduction in floral resource abundance and diversity is generally observed in agro-ecosystems, along with widespread exposure to pesticides. Therefore, a better understanding on how the availability and quality of pollen diets can modulate honeybee sensitivity to pesticides is required. For that purpose, we evaluated the toxicity of acute exposure and chronic exposures to field realistic and higher concentrations of azoxystrobin (fungicide) and sulfoxaflor (insecticide) in honeybees provided with pollen diets of differing qualities (named <i>S</i> and <i>BQ</i> pollens). We found that pollen intake reduced the toxicity of the acute doses of pesticides. Contrary to azoxystrobin, chronic exposures to sulfoxaflor increased by 1.5- to 12-fold bee mortality, which was reduced by pollen intake. Most importantly, the risk of death upon exposure to a high concentration of sulfoxaflor was significantly lower for the <i>S</i> pollen diet when compared with the <i>BQ</i> pollen diet. This reduced pesticide toxicity was associated with a higher gene expression of vitellogenin, a faster sulfoxaflor metabolization and a lower concentration of the phytochemical <i>p</i>-coumaric acid, known to upregulate detoxification enzymes. Thus, our study revealed that pollen quality can influence the ability of bees to metabolize pesticides and withstand their detrimental effects, providing another strong argument for the restoration of suitable foraging habitat.

农业生态系统中普遍存在花卉资源丰度与多样性降低的现象，同时蜜蜂会广泛接触各类农药。因此，亟需更全面地阐明花粉日粮的可获得性与品质如何调控蜜蜂对农药的敏感性。为此，我们针对饲喂不同品质花粉日粮（分别命名为S花粉与BQ花粉）的蜜蜂，评估了田间实际浓度及更高浓度的嘧菌酯（azoxystrobin，杀菌剂）与氟啶虫胺腈（sulfoxaflor，杀虫剂）的急性与慢性暴露毒性。研究发现，摄入花粉可降低急性农药暴露的毒性。与嘧菌酯不同，慢性暴露于氟啶虫胺腈会使蜜蜂死亡率升高1.5至12倍，而摄入花粉可缓解这一效应。最为关键的是，相较于BQ花粉日粮，饲喂S花粉日粮的蜜蜂在高浓度氟啶虫胺腈暴露下的死亡风险显著更低。这种农药毒性的降低，与卵黄蛋白原（vitellogenin）的更高水平基因表达、更快的氟啶虫胺腈代谢速率，以及已知可上调解毒酶表达的植物源化合物对香豆酸（p-coumaric acid）的更低浓度密切相关。综上，本研究揭示花粉品质可影响蜜蜂代谢农药并抵御其有害影响的能力，为恢复适宜的蜜蜂觅食生境提供了又一有力依据。