Abstract
BackgroundHost adaptation is the primary determinant of insect diversification. However, knowledge of different host ranges in closely related species remains scarce. The brown planthopper (Nilaparvata lugens, BPH) and the small brown planthopper (Laodelphax striatellus, SBPH) are the most destructive insect pests within the family Delphacidae. These two species differ in their host range (SBPH can well colonize rice and wheat plants, whereas BPH survives on only rice plants), but the underlying mechanism of this difference remains unknown. High-throughput sequencing provides a powerful approach for analyzing the association between changes in gene expression and the physiological responses of insects. Therefore, gut transcriptomes were performed to elucidate the genes associated with host adaptation in planthoppers. The comparative analysis of planthopper responses to different diets will improve our knowledge of host adaptation regarding herbivorous insects.ResultsIn the present study, we analyzed the change in gene expression of SBPHs that were transferred from rice plants to wheat plants over the short term (rSBPH vs tSBPH) or were colonized on wheat plants over the long term (rSBPH vs wSBPH). The results showed that the majority of differentially expressed genes in SBPH showed similar changes in expression for short-term transfer and long-term colonization. Based on a comparative analysis of BPH and SBPH after transfer, the genes associated with sugar transporters and heat-shock proteins showed similar variation. However, most of the genes were differentially regulated between the two species. The detoxification-related genes were upregulated in SBPH after transfer from the rice plants to the wheat plants, but these genes were downregulated in BPH under the same conditions. In contrast, ribosomal-related genes were downregulated in SBPH after transfer, but these genes were upregulated in BPH under the same conditions.ConclusionsThe results of this study provide evidence that host plants played a dominant role in shaping gene expression and that the low fitness of BPH on wheat plants might be determined within 24 h after transfer. This study deepens our understanding of different host ranges for the two planthopper species, which may provide a potential strategy for pest management.
Highlights
Host adaptation is the primary determinant of insect diversification
According to the survival analysis, more than 90% of rice-colonizing BPH strains (rBPH) survived on rice plants for 12 days, which was significantly higher than that on wheat plants (Fig. 1a)
These results indicate that Brown planthopper (BPH) could ingest wheat sap and survive on wheat plants for a short time but not for an extended period
Summary
Host adaptation is the primary determinant of insect diversification. knowledge of different host ranges in closely related species remains scarce. The brown planthopper (Nilaparvata lugens, BPH) and the small brown planthopper (Laodelphax striatellus, SBPH) are the most destructive insect pests within the family Delphacidae These two species differ in their host range (SBPH can well colonize rice and wheat plants, whereas BPH survives on only rice plants), but the underlying mechanism of this difference remains unknown. Successful host adaptation involves several essential traits of herbivorous insects, including the abilities to detect the correct plants, acquire nutrients while avoiding intoxication, and overcome plant defenses [2]. Absence of these essential traits have been reported to result in the failure of an insect to feed on specific plants [3,4,5,6]. Comparative transcriptomic analysis of closely related taxa provides an ideal approach for revealing the distinctions in host adaptation across herbivorous species
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
