Abstract：
The social division of labor within the honeybee colony is closely related to the age of the bees, and the age structure is essential to the development and survival of the colony. Differences in tolerance to pesticides and other external stresses among worker bees of different ages may be related to their social division of labor and corresponding physiological states. Pyraclostrobin was widely used to control the fungal diseases of nectar and pollen plants, though it was not friend to honey bees and other pollinators. This work aimed to determine the effects of field recommended concentrations of pyraclostrobin on the activities of protective and detoxifying enzymes, on the expression of genes involved in nutrient metabolism, and immune response in worker bees of different ages determined to investigate the physiological and biochemical differences in sensitivity to pyraclostrobin among different age of worker bees. The result demonstrates that the tolerance of adult worker bees to pyraclostrobin was negatively correlated with their age, and the significantly reduced survival rate of forager bees (21 day-old) with continued fungicide exposure. The activities of protective enzymes (CAT and SOD) and detoxifying enzymes (CarE, GSTs and CYP450) in different ages of adult worker bees were significantly altered, indicating the physiological response and the regulatory capacity of worker bees of different ages to fungicide stress was variation. Compared with 1 and 8 day-old worker bees, the expression of nutrient-related genes (ilp1 and ilp2) and immunity-related genes (apidaecin and defensin1) in forager bees (21 day-old) was gradually downregulated with increasing pyraclostrobin concentrations. Moreover, the expression of vitellogenin and hymenoptaecin in forager bees (21 day-old) was also decreased in high concentration treatment groups (250 and 313 mg/L). The present study confirmed the findings of the chronic toxicity of pyraclostrobin on the physiology and biochemistry of worker bees of different ages, especially to forager bees (21 day-old). These results would provide important physiological and biochemical insight for better understanding the potential risks of pyraclostrobin on honeybees and other non-target pollinators.
摘要：
蜜蜂群体内部的社会分工与蜜蜂的年龄密切相关,年龄结构对殖民地的发展和生存至关重要。不同年龄工蜂对农药和其他外部胁迫的耐受性差异可能与其社会分工和相应的生理状态有关。Pyraclostrobin被广泛用于控制花蜜和花粉植物的真菌疾病，虽然它不是蜜蜂和其他传粉者的朋友。这项工作旨在确定现场推荐浓度的吡唑酮酯对保护性和解毒酶活性的影响，关于与营养代谢有关的基因的表达，并对不同年龄工蜂的免疫反应进行了测定，以研究不同年龄工蜂对吡唑醇酯敏感性的生理生化差异。结果表明，成年工蜂对吡唑酮的耐受性与年龄呈负相关，并且在持续的杀菌剂暴露下，觅食蜜蜂（21日龄）的存活率显着降低。保护酶（CAT和SOD）和解毒酶（CarE，GSTs和CYP450）在不同年龄的成年工蜂中发生了显着变化，表明不同年龄工蜂对杀菌剂胁迫的生理反应和调节能力存在差异。与1和8日龄工蜂相比，营养相关基因（ilp1和ilp2）和免疫相关基因（apidaecin和defensin1）在觅食蜜蜂（21日龄）中的表达随着吡唑酮酯浓度的增加而逐渐下调。此外，在高浓度处理组（250和313mg/L）中，觅食蜜蜂（21日龄）中卵黄蛋白原和膜凝素的表达也降低。本研究证实了吡唑酮酯对不同年龄工蜂生理生化的慢性毒性研究结果，尤其是觅食蜜蜂（21日龄）。这些结果将提供重要的生理和生化见解，以更好地了解吡唑醇酯对蜜蜂和其他非目标传粉者的潜在风险。
