Evaluating the possibility of horizontal transfer of small RNAs from Sidr pollen to honey bee and their interaction in the host cell

The existence of molecular relationship between different organisms through diet-derived plant miRNAs is one of the most challenging debates of the last decade. Considering the mutual relationship between plants and pollinating insects, including honey bee as the most important pollinating insect, the aim of the present study is to investigate the existence of molecular relationship in the interaction between plants and honey bee through plant-derived xenomiRs can be very important and create a new perspective of the beneficial effects of this relationship.
 
Pollen was collected by pollen trap device from honey bee colonies that were located near Sidr trees. Honey bees were fed under controlled conditions in two groups (fed by Sidr pollen as treatment and fed by sugar syrup as control). Following the feeding experiments, the bees were anesthetized using cold and their midgut tissue was collected and used for RNA extraction. After the Small RNA sequencing of the samples, the identification of pollen miRNAs and their tracking in the bee body was done using different bioinformatics analysis. Finally, the target genes of the detected plant miRNAs in the bee body and the molecular pathway involved by them were determined.
 
The results of bioinformatics analysis indicate the detection of eleven plant miRNAs including miR-148a, miR-26a, miR-21-5p, miR-143, miR-27a,miR-203, let-7g, miR-126, miR-206, miR-30d and miR-199b into the tissue of honey bees fed by Sidr pollen. miRNAs participate in various biological processes through their target genes. In the present study, 99 target genes for the detected plant miRNAs were predicted in honey bee genome. The result of KEGG pathway analysis showed that target genes are significantly involved in 23 different biological pathways.
 
The result of the current study clearly present the role of plant-derived xenomiRs in the regulation of honey bee gene expression. Therefore on one hand, these findings extend our understanding of the molecular interaction between honey bees and flowering plants, and on the other hand, it can be used as a practical road map for breeding studies in order to improve honey production and deal with diseases related to bees, as the most important pollinating insects in the 21st century’s agriculture.