Damage to the behavior and physiological functions of Apis mellifera (Hymenoptera: Apidae) by monocrotaline via the modulation of tryptophan metabolism and the corazonin receptor

• Published in: The Science of the total environment 2024-11, Vol.952, p.175931, Article 175931
• Main Authors: Hua, Qi, Chi, Xuepeng, Zhang, Wei, Song, Hongyu, Wang, Ying, Liu, Zhenguo, Wang, Hongfang, Xu, Baohua
• Format: Article
• Language: English
• Subjects: Animals; Bees - drug effects; Bees - physiology; Behavior, Animal - drug effects; Brain transcriptome; Corazonin receptor; Hemolymph - metabolism; Hemolymph metabolome; Honeybees; Insect Proteins - genetics; Insect Proteins - metabolism; Monocrotaline; Neuropeptides; Tryptophan - metabolism
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.175931

Monocrotaline (MCT) is a toxic pyrrolizidine alkaloid found in plants of the Crotalaria genus. As primary pollinators of Crotalaria plants, honeybees come into contact with this harmful substance. However, limited research has been conducted on the effects of MCT on Apis mellifera, particularly the risks of long-term exposure to sublethal concentrations. Through evaluating the proboscis extension reflex (PER) ability, analyzing the honeybee brain transcriptome, and analyzing the honeybee hemolymph metabolome, we discovered that sublethal concentrations of MCT impair the olfactory and memory capabilities of honeybees by affecting tryptophan (Trp) metabolism. Furthermore, MCT upregulates the expression of the corazonin receptor (CrzR) gene in the honeybee brain, which elevates reactive oxygen species (ROS) levels in the brain while reducing glucose levels in the hemolymph, consequently shortening the honeybees' lifespan. Our findings regarding the multifaceted impact of MCT on honeybees lay the foundation for exploring its toxicological pathways and management in honeybee populations. [Display omitted] •The sublethal concentration of monocrotaline impairs the olfactory and memory abilities of Apis mellifera.•Monocrotaline influences the transcription levels of memory-related genes in the honeybee brain.•Monocrotaline influences honeybee behavior through tryptophan metabolism.•Monocrotaline influences honeybee physiological functions by upregulating the expression of CrzR in the honeybee brain.