Immune-related gene expression of Apis mellifera larvae in response to cold stress and Abscisic Acid (ABA) dietary supplementation

Abstract

The effects of parasites, pathogens and agrochemical exposure combined with the cold temperatures of winter in temperate-climate regions contribute to the immunosuppression of honey bees. Recently, we demonstrated that abscisic acid (ABA) dietary supplementation increased the tolerance of Apis mellifera brood to low temperatures. Here, we study the relationship between cold exposure, dietary ABA supplementation, and the expression of genes involved in the immune response of in-vitro-reared bee larvae. We found that cold exposure induced the expression of several immune-associated genes in honey bee larvae, supporting that the immune system is active during the cold stress response in A. mellifera. At the same time, the ingestion of ABA alone increased the expression levels of the Toll pathway receptor toll18W and nitric oxide synthase (nos) genes, which were induced also by low temperatures, reinforcing the connection between honey bees’ response to cold stress and ABA.

Keywords:

• abscisic acid
• Apis mellifera
• cold stress
• gene expression
• immune response

Acknowledgments

The authors would like to thank Dr. Yves Le Conte for his advice, the CONICET and the UNMdP. The authors would like to thank both the editor and the reviewers for their thoughtful comments and dedication that lead to a better version of the entire work. PN is an assistant researcher from CONICET, Argentina.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by the Agencia Nacional de Promoción Cientifica Tecnológica (ANPCyT) through the grants PICT-2012-0594 granted to ME, PICT 2013-0904 granted to LL and PICT 2014-3145 granted to LR.