Effect Of Interactions Between Carbendazim And Nosema Ceranae On The Development Of Worker Bees

Honey bees are the most important pollinators in nature,and they are of great significance in protecting biodiversity and ecosystems and promoting social and economic development.However,in recent years,the number of bee colonies in the world has been drastically reduced,which seriously threatens human food security and ecosystem stability.The sublethal effects of the widespread use of pesticides generally have a potential impact on the development of bees,and the infestation of various pathogens will threaten the bees and bee products.Previous studies mainly focused on the impact of a single stressor on bees,ignoring the reality that bees coexist in multiple stressors under natural conditions.Carbendazim is the pesticide with the highest detection rate in pollen,and Nosema ceranae has become the main pathogen of bee infections worldwide.In this study,carbendazim and Nosema ceranae were used to infect honeybees individually or together to explore the effects of multiple stressors on honeybees.In this study,we used the combined stress of carbendazim and N.ceranae to count the deaths of bees,and performed HE staining analysis on the midgut of adult worker bees of Western honeybees,and explored the effects of carbendazim and N.ceranae common stress affects the lifespan and midgut of worker bees in western honeybees.And statistically analyzed the consumption of pollen and sugar water by bees after the common stress of carbendazim and N.ceranae,to determined the effect of common stress of carbendazim and N.ceranae on the nutrient consumption of worker bees of western honeybees.At the same time,10-day-old western honey bee adult worker bees was measured the detoxification enzyme activity,as well as the expression of antimicrobial peptides,metabolism and memory and other related genes to study the common stress of carbendazim and N.ceranae on the detoxification enzymes of the western honey bee adult worker bees.In addition,we combined Illumina sequencing to generate the A.mellifera midgut transcriptome.To identify the profile of differentially expressed genes(DEGs)in the midgut of honeybees under the common stress of N.ceranae and carbendazim.The main findings are as follows:(1)Studies have found that sublethal doses of carbendazim will affect the survival rate of bees.N.ceranae has a more adverse effect on the survival rate of bees,but the combined effect of carbendazim and N.ceranae will not affect the survival rate of bees.However,the combined effect of carbendazim and N.ceranae did not have a synergistic effect on the survival rate of bees.With the increase of age,carbendazim and N.ceranae persistent infection will cause harm to bees midgut.(2)Exposed of carbendazim will increase the consumption of sugar water and reduce the consumption of pollen by bees.Bees infected with N.ceranae will consume less sugar and pollen.When bees are co-infected by N.ceranae and carbendazim,their sugar water consumption will increase significantly,and their pollen consumption will decrease.N.ceranae infection can increase the weight of the midgut of bees,and carbendazim exposure may inhibit this effect of N.ceranae.(3)The common stress between carbendazim and N.ceranae will not have a significant effect on the three detoxification enzymes of AChE,GST and CarE of bees,but it will affect the gene expression of immune response,nutritional metabolism and learning and memory of bees.(4)The common stress of carbendazim and N.ceranae will induce more DEGs,and will affect the host’s metabolic level and activate more metabolic pathways.The genes encoding trehalose transporter and the genes encoding trehalase are up-regulated,indicating that the common stress of carbendazim and N.ceranae will affect the metabolic activities of bees.This research is the first to study the effect of carbendazim and N.ceranae on bees.The data will help us clearly understand the co-stress of carbendazim and N.ceranae on the survival rate,food intake and midgut in western honeybees.It provides a reference for the rational use of carbendazim and the prevention and treatment of N.ceranae.Meanwhile,the response mechanism of 10-day-old worker bees midgut in response to the combined stress of carbendazim and N.ceranae was analyzed at the molecular level,which provided important data support for e clarifying the response mechanism of adult worker bees to the combined stress of carbendazim and N.ceranae.