Glutathione S-transferases (GSTs) are members of a multifunctional antioxidant enzyme superfamily that play pivotal roles in both detoxification and protection against oxidative damage caused by reactive oxygen species. In this study, a complementary DNA (cDNA) encoding a sigma class GST was identified in the Chinese honey bee, Apis cerana cerana (AccGSTS1). AccGSTS1 was constitutively expressed in all tissues of adult worker bees, including the brain, fat body, epidermis, muscle, and midgut, with particularly robust transcription in the fat body. Relative messenger RNA expression levels of AccGSTS1 at different developmental stages varied, with the highest levels of expression observed in adults. The potential function of AccGSTS1 in cellular defenses against abiotic stresses (cold, heat, UV, H₂O₂, HgCl₂, and insecticides) was investigated. AccGSTS1 was significantly upregulated in response to all of the treatment conditions examined, although the induction levels were varied. Recombinant AccGSTS1 protein showed characteristic glutathione-conjugating catalytic activity toward 1-chloro-2,4-dinitrobenzene. Functional assays revealed that AccGSTS1 could remove H₂O₂, thereby protecting DNA from oxidative damage. Escherichia coli overexpressing AccGSTS1 showed long-term resistance under conditions of oxidative stress. Together, these results suggest that AccGSTS1 is a crucial antioxidant enzyme involved in cellular antioxidant defenses and honey bee survival.

Oxidative stress may be the most significant threat to the survival of living organisms. Glutathione S-transferases (GSTs) serve as the primary defences against xenobiotic and peroxidative-induced oxidative damage. In contrast to other well-defined GST classes, the Omega-class members are poorly understood, particularly in insects. Here, we isolated and characterised the GSTO2 gene from Apis cerana cerana (AccGSTO2). The predicted transcription factor binding sites in the AccGSTO2 promoter suggested possible functions in early development and antioxidant defence. Real-time quantitative PCR (qPCR) and western blot analyses indicated that AccGSTO2 was highly expressed in larvae and was predominantly localised to the brain tissue in adults. Moreover, AccGSTO2 transcription was induced by various abiotic stresses. The purified recombinant AccGSTO2 exhibited glutathione-dependent dehydroascorbate reductase and peroxidase activities. Furthermore, it could prevent DNA damage. In addition, Escherichia coli overexpressing AccGSTO2 displayed resistance to long-term oxidative stress exposure in disc diffusion assays. Taken together, these results suggest that AccGSTO2 plays a protective role in counteracting oxidative stress.

As one of the predominant pollinator, honeybees provide important ecosystem service to crops and wild plants, and generate great economic benefit for humans. Unfortunately, there is clear evidence of recent catastrophic honeybee colony failure in some areas, resulting in markedly negative environmental and economic effects. It has been demonstrated that various environmental stresses, including both abiotic and biotic stresses, functioning singly or synergistically, are the potential drivers of colony collapse. Honeybees can use many defense mechanisms to decrease the damage from environmental stress to some extent. Here, we synthesize and summarize recent advances regarding the effects of environmental stress on honeybees and the wisdom of honeybees to respond to external environmental stress. Furthermore, we provide possible future research directions about the response of honeybees to various form of stressors.