Xiaoyun Hu,Shuangli Su,Qingsong Liu,Yaoyu Jiao,Yufa Peng,Yunhe Li,Ted CJ Turlings
Plants typically release large quantities of volatiles in response to herbivory by insects. This benefits the plants by, for instance, attracting the natural enemies of the herbivores. We show that the brown planthopper (BPH) has cleverly turned this around by exploiting herbivore-induced plant volatiles (HIPVs) that provide safe havens for its offspring. BPH females preferentially oviposit on rice plants already infested by the rice striped stem borer (SSB), which are avoided by the egg parasitoid Anagrus nilaparvatae, the most important natural enemy of BPH. Using synthetic versions of volatiles identified from plants infested by BPH and/or SSB, we demonstrate the role of HIPVs in these interactions. Moreover, greenhouse and field cage experiments confirm the adaptiveness of the BPH oviposition strategy, resulting in 80% lower parasitism rates of its eggs. Besides revealing a novel exploitation of HIPVs, these findings may lead to novel control strategies against an exceedingly important rice pest.
Insecticide resistance in pest control poses a threat to agricultural production and human health. Numerous insect species express genes coding for detoxification enzymes that have broad substrate promiscuity thus conferring resistance to various insecticides. However, whether the homologs of these genes play similar roles in resistance phenotypes of closely related species remains largely unclear. Therefore, this study compares the resistance profiles of three major rice planthopper species (Delphacidae) ( Laodelphax striatellus , Nilaparvata lugens , and Sogatella furcifera ) based on the metabolic activity of their cytochrome P450s. Genome-wide analyses resulted in 68, 70, and 64 P450 genes in L. striatellus , N. lugens , and S. furcifera , respectively. Phylogenetic analyses among these genes found that most resistance-related genes in one species had homologs in other planthopper species. The most resistance-relevant orthogroup ( CYP6ER s) showed higher evolutionary instability than most other groups. RNAi and in vitro metabolism assays revealed that CYP6ER s confers more divergent insecticide resistance profiles among planthopper species than the other two major resistance-related P450 subfamilies ( CYP6AY s and CYP4C61 s). Alphafold-based structural predictions and alignments suggested that P450 orthogroups with higher phylogenetic instability tended to have less structural similarities, resulting in more divergent metabolic profiles. This relationship was also in silico validated on Aphidae aphids and Lepidoptera noctuids. This study proposes combined phylogenetic and toxicogenomic analyses for understanding CYPome-based insecticide resistance convergency and divergency among closely related pests. These findings may improve the accuracy and rationality of chemical pest control.
危险品化学品经营许可证（带存储）