The insect gustatory system participates in identifying potential food sources and avoiding toxic compounds.During this process,gustatory receptors(GRs)recognize feeding stimulant and deterrent compounds.However,the G...The insect gustatory system participates in identifying potential food sources and avoiding toxic compounds.During this process,gustatory receptors(GRs)recognize feeding stimulant and deterrent compounds.However,the GRs involved in recognizing stimulant and deterrent compounds in the red imported fire ant,Solenopsis invicta,remain unknown.Therefore,we conducted a study on the genes SinvGR1,SinvGR32b,and SinvGR28a to investigate the roles of GRs in detecting feeding stimulant and deterrent compounds.In this current study,we found that sucrose and fructose are feeding stimulants and the bitter compound quinine is a feeding deterrent.The fire ant workers showed significant behavior changes to avoid the bitter taste in feeding stimulant compounds.Reverse transcription quantitative real-time polymerase chain reaction results from developmental stages showed that the SinvGR1,SinvGR32b,and SinvGR28a genes were highly expressed in fire ant workers.Tissue-specific expression profiles indicated that SinvGR1,SinvGR32b,and SinvGR28a were specifically expressed in the antennae and foreleg tarsi of workers,whereas SinvGR32b gene transcripts were also highly accumulated in the male antennae.Furthermore,the silencing of SinvGRI or SinvGR32b alone and the co-silencing of both genes disrupted worker stimulation and feeding on sucrose and fructose.The results also showed that SinvGR28a is required for avoiding quinine,as workers with knockdown of the SinvGR28a gene failed to avoid and fed on quinine.This study first identified stimulant and deterrent compounds of fire ant workers and then the GRs involved in the taste recognition of these compounds.This study could provide potential target gustatory genes for the control of the fire ant.展开更多
Insects often face both conditions with sufficient nutrients and conditions of undernutrition in the field.Through gustatory receptors,insects sense nutrients and regulate their physiological functions such as feeding...Insects often face both conditions with sufficient nutrients and conditions of undernutrition in the field.Through gustatory receptors,insects sense nutrients and regulate their physiological functions such as feeding and reproduction.However,it remains unclear whether signaling pathways activated by gustatory receptors depend on the concentration of nutrients and whether the difference in signaling pathways directly affects insects’physiological functions.Herein,we found that a sugar gustatory receptor,NlGr11,from the brown planthopper(BPH),Nilaparvata lugens,activated G protein-coupled signaling and ionotropic pathways when bound to high galactose concentration.BPHs subsequently demonstrated longer feeding times,feeding loads,and higher vitellogenin(NlVg)expression than BPHs exposed to high galactose concentrations,which only activated the ionotropic pathway.For the first time,our findings link plant nutrient conditions,signaling pathways activated by nutrients,and their gustatory receptors,and nutrient dose-dependent feeding efficacy and vitellogenin(Vg)expression in an insect.This will help us to better understand the molecular mechanism for insect feeding strategies on plants at different stages of nutritional conditions.展开更多
Insects employ various types of gustatory receptors(GRs)to identify nutrient-rich food and avoid toxic substances.The larval gustatory system is the critical checkpoint for food acceptance or rejection.As a specialist...Insects employ various types of gustatory receptors(GRs)to identify nutrient-rich food and avoid toxic substances.The larval gustatory system is the critical checkpoint for food acceptance or rejection.As a specialist herbivore,the larvae of Bactrocera minax feed only on unripe citrus fruits.However,how larvae use GRs to check and adapt to the secondary metabolites in unripe citrus fruits remains unknown.In this study,we first performed developmental expression profiles showing that most BminGRs genes were highly expressed in 1st and 2nd instar larvae and that tissue-specific expression indicated high expression of most BminGRs genes in the mouthparts of 2nd instar larvae.Furthermore,we found that silencing BminGR59f by RNA interference(RNAi)affected the growth of 2nd instar B.minax larvae.Hesperidin and naringin were screened as ligands of BminGR59f via RNAi and cell calcium imaging,and the combination of these two flavones increased the body weight of larvae.In summary,we identified a novel gustatory perception pattern in B.minax for detecting hesperidin and naringin,which boosted the growth of B.minax larvae.These results shed light on how specialist herbivores detect and adapt to host metbolites in adverse environments depending on larval GRs.展开更多
基金supported by the National Key R&D Program of China(2021YFD1000500)the Foundation of Guangdong Academy of Agricultural Sciences(R2023PY-JX010)the Natural Science Foundation of Guangdong Province(2021A1515012445).
文摘The insect gustatory system participates in identifying potential food sources and avoiding toxic compounds.During this process,gustatory receptors(GRs)recognize feeding stimulant and deterrent compounds.However,the GRs involved in recognizing stimulant and deterrent compounds in the red imported fire ant,Solenopsis invicta,remain unknown.Therefore,we conducted a study on the genes SinvGR1,SinvGR32b,and SinvGR28a to investigate the roles of GRs in detecting feeding stimulant and deterrent compounds.In this current study,we found that sucrose and fructose are feeding stimulants and the bitter compound quinine is a feeding deterrent.The fire ant workers showed significant behavior changes to avoid the bitter taste in feeding stimulant compounds.Reverse transcription quantitative real-time polymerase chain reaction results from developmental stages showed that the SinvGR1,SinvGR32b,and SinvGR28a genes were highly expressed in fire ant workers.Tissue-specific expression profiles indicated that SinvGR1,SinvGR32b,and SinvGR28a were specifically expressed in the antennae and foreleg tarsi of workers,whereas SinvGR32b gene transcripts were also highly accumulated in the male antennae.Furthermore,the silencing of SinvGRI or SinvGR32b alone and the co-silencing of both genes disrupted worker stimulation and feeding on sucrose and fructose.The results also showed that SinvGR28a is required for avoiding quinine,as workers with knockdown of the SinvGR28a gene failed to avoid and fed on quinine.This study first identified stimulant and deterrent compounds of fire ant workers and then the GRs involved in the taste recognition of these compounds.This study could provide potential target gustatory genes for the control of the fire ant.
基金supported by the National Natural Science Foundation of China(31730073,U1401212)Guizhou Science and Technology Project(qiankeheji-zk[2021]General 135).
文摘Insects often face both conditions with sufficient nutrients and conditions of undernutrition in the field.Through gustatory receptors,insects sense nutrients and regulate their physiological functions such as feeding and reproduction.However,it remains unclear whether signaling pathways activated by gustatory receptors depend on the concentration of nutrients and whether the difference in signaling pathways directly affects insects’physiological functions.Herein,we found that a sugar gustatory receptor,NlGr11,from the brown planthopper(BPH),Nilaparvata lugens,activated G protein-coupled signaling and ionotropic pathways when bound to high galactose concentration.BPHs subsequently demonstrated longer feeding times,feeding loads,and higher vitellogenin(NlVg)expression than BPHs exposed to high galactose concentrations,which only activated the ionotropic pathway.For the first time,our findings link plant nutrient conditions,signaling pathways activated by nutrients,and their gustatory receptors,and nutrient dose-dependent feeding efficacy and vitellogenin(Vg)expression in an insect.This will help us to better understand the molecular mechanism for insect feeding strategies on plants at different stages of nutritional conditions.
基金This study was funded by National Natural Science Foundation of China(31972270,31661143045)agricultural public welfare industry research from Ministry of Agriculture of People's Republic of China(201503137)+1 种基金the Joint Program of the Israel Science Foundation and the Science Foundation of China(2482/16)the fundamental research funds for the central universities(2662020ZKPY018).
文摘Insects employ various types of gustatory receptors(GRs)to identify nutrient-rich food and avoid toxic substances.The larval gustatory system is the critical checkpoint for food acceptance or rejection.As a specialist herbivore,the larvae of Bactrocera minax feed only on unripe citrus fruits.However,how larvae use GRs to check and adapt to the secondary metabolites in unripe citrus fruits remains unknown.In this study,we first performed developmental expression profiles showing that most BminGRs genes were highly expressed in 1st and 2nd instar larvae and that tissue-specific expression indicated high expression of most BminGRs genes in the mouthparts of 2nd instar larvae.Furthermore,we found that silencing BminGR59f by RNA interference(RNAi)affected the growth of 2nd instar B.minax larvae.Hesperidin and naringin were screened as ligands of BminGR59f via RNAi and cell calcium imaging,and the combination of these two flavones increased the body weight of larvae.In summary,we identified a novel gustatory perception pattern in B.minax for detecting hesperidin and naringin,which boosted the growth of B.minax larvae.These results shed light on how specialist herbivores detect and adapt to host metbolites in adverse environments depending on larval GRs.
