As predominant pollinators, honeybees are important for crop production and terrestrial ecosystems. Recently, various environmental stresses have led to large declines in honeybee populations in many regions. The ability of honeybees to respond to these stresses is critical for their survival. However, the details of the stress defense mechanisms of honeybees have remained elusive. Here, we found that the Nuclear Factor Y (NF-Y) family (containing NF-YA, NF-YB, and NF-YC) is a novel stress mediator family that regulates honeybee environmental stress resistance. NF-YA localized in the nucleus, NF-YB accumulated in the cytoplasm, and NF-YC presented in both the nucleus and cytoplasm. NF-YC interacted with NF-YA and NF-YB in vitro and in vivo, and the nuclear import of NF-YB relied on its interaction with NF-YC. We further found that the expression of NF-Y was induced under multiple stress conditions. In addition, NF-Y regulated many stress responses and antioxidant genes at the transcriptome-wide level, and knockdown of NF-Y repressed the expression of stress-inducible genes, particularly LOC108003540 and LOC107994062, under adverse circumstances. Silencing NF-Y lowered honeybee stress resistance by reducing total antioxidant capacity and enhancing oxidative impairment. Collectively, these results indicate that NF-Y plays important roles in stress responses. Our study sheds light on the underlying defense mechanisms of honeybees under environmental stress.

作为主要的传粉媒介，蜜蜂对作物生产和陆地生态系统很重要。最近，各种环境压力已导致许多地区的蜜蜂种群大量减少。蜜蜂对这些压力的反应能力对其生存至关重要。然而，蜜蜂的压力防御机制的细节仍然难以捉摸。在这里，我们发现核因子Y（NF-Y）家族（包含NF-YA，NF-YB和NF-YC）是调节蜜蜂环境抗性的新型应激介体家族。NF-YA位于细胞核中，NF-YB聚集在细胞质中，而NF-YC则存在于细胞核和细胞质中。NF-YC在体内外均与NF-YA和NF-YB相互作用，NF-YB的核输入依赖于其与NF-YC的相互作用。在多种压力条件下诱导了NF-Y。此外，NF-Y在转录组水平上调节许多应激反应和抗氧化基因，而在不利情况下，NF-Y的敲低抑制了应激诱导基因的表达，特别是LOC108003540和LOC107994062。沉默NF-Y会降低总抗氧化能力并增强氧化损伤，从而降低蜜蜂的抗逆性。总的来说，这些结果表明NF-Y在应激反应中起重要作用。我们的研究揭示了蜜蜂在环境压力下的潜在防御机制。