Poster Display
Physiology, Biochemistry, and Toxicology
Qian Ding
Zhengzhou University
Zhengzhou, Henan, China (People's Republic)
Lixiang Wang
Zhengzhou University
Zhengzhou, Henan, China (People's Republic)
Xianchun Li, Ph.D. (he/him/his)
Professor
University of Arizona
Tucson, Arizona
When the target pests harm Bt crops, they often simultaneously ingest Bt toxins and plant allelochemicals, but the synergistic and antagonistic mechanisms of these two types of toxins remain underexplored. Previous studies have found that plant secondary flavone and Vip3Aa (Vegetative insecticidal protein) have synergistic effects on Spodoptera frugiperda. In this study, the synergistic mechanism of flavone and Vip3Aa on S. frugiperda was explored from different biological levels of individuals, tissues and cells, combined with RNA-seq. We found that flavone and Vip3Aa synergistically inhibited the viability of S. frugiperda and caused irreversible apoptosis and damage in the midgut of larvae. Secondly, through apoptosis/proliferation detection, it was found that flavone and Vip3Aa could synergistically promote Sf9 cell apoptosis and inhibit Sf9 cell proliferation. Transcriptome analysis results indicated that the differential genes in the combined treatment group of flavonoids and Vip3Aa were significantly enriched in the FoxO pathway that related to apoptosis and proliferation. Finally, by constructing a FoxO overexpression cell line, adding FoxO pathway inhibitors and RNAi, it was confirmed that flavonoids and Vip3A jointly activate the FoxO pathway to affect cell apoptosis and proliferation, thereby enhancing their virulence against the S. frugiperda, ultimately mediating the synergistic effect of flavonoids and Vip3AA on the S. frugiperda.