Panonychus citriMcGregor(Acari:Tetranychidae),a destructive citrus pest,causes considerable annual economic losses due to its short lifespan and rapid resistancedevelopment.MicroRNA(miRNA)-induced RNA interference is ...Panonychus citriMcGregor(Acari:Tetranychidae),a destructive citrus pest,causes considerable annual economic losses due to its short lifespan and rapid resistancedevelopment.MicroRNA(miRNA)-induced RNA interference is a promising approachfor pest control because of endogenous regulation of pest growth and development.Tosearch for miRNAs with potential insecticidal activity inP.citri,genome-wide analysis ofmiRNAs at different developmental stages was conducted,resulting in the identificationof 136 miRNAs,including 73 known and 63 novel miRNAs.A total of 17 isomiRNAsand 12 duplicated miRNAs were characterized.MiR-1 and miR-252-5p were identified asreference miRNAs forP.citriandTetranychus urticae.Based on differential expressionanalysis,treatments with miR-let-7a and miR-315 mimics and the miR-let-7a antagomirsignificantly reduced the egg hatch rate and resulted in abnormal egg development.Over-expression or downregulation of miR-34-5p and miR-305-5p through feeding significantlydecreased the adult eclosion rate and caused molting defects.The 4 miRNAs,miR-let-7a,miR-315,miR-34-5p,and miR-305-5p,had important regulatory functions and insectici-dal properties in egg hatching and adult eclosion.In general,these data advance our un-derstanding of miRNAs in mite biology,which can assist future studies on insect-specificmiRNA-based green pest control technology.展开更多
Insecticide resistance in Panonychus citri is a major obstacle to mite control in citrus orchards.Pyrethroid insecticides are continually used to control mites in China,although resistance to pyrethroids has evolved i...Insecticide resistance in Panonychus citri is a major obstacle to mite control in citrus orchards.Pyrethroid insecticides are continually used to control mites in China,although resistance to pyrethroids has evolved in some populations.Here,the resistance to the pyrethroid fenpropathrin was investigated and 7 out of 8 field-collected populations of P citri exhibited a high level of resistance,ranging from 171-fold to 15391-fold higher than the susceptible(SS)comparison strain.Three voltage-gated sodium channel(VGSC)mutations were identified in the tested populations:L1031V,F1747L,and F17511.Amplicon sequencing was used to evaluate the frequency of these mutations in the 19 field populations.L1031V and F1751I were present in all populations at frequencies of 11.6%-82.1%and 0.5%-31.8%,respectively,whereas the F1747L mutation was only present in 12 populations from Chongqing,Sichuan,Guangxi,and Yunnan provinces.Introduction of these mutations singly or in combination into transgenic flies significantly increased their resistance to fenpropathrin and these flies also exhibited reduced mortality after exposure to the pyrethroids permethrin andβ-cypermethrin.Panonychus citri VGSC homology modeling and ligand docking indicate that F1747 and F1751 form direct binding contacts with pyrethroids,which are lost with mutation,whereas L1031 mutation may diminish pyrethroid effects through an allosteric mechanism.Overall,the results provide molecular markers for monitoring pest resistance to pyrethroids and offer new insights into the basis of pyrethroid actions on sodium channels.展开更多
基金supported by the National Natural Sci-ence Foundation of China(31972272,31871969)the Fundamental Research Funds for the Central Universi-ties(SWU-XDPY22001)of Chinathe China Agri-cultural Research System of MOA and MARA。
文摘Panonychus citriMcGregor(Acari:Tetranychidae),a destructive citrus pest,causes considerable annual economic losses due to its short lifespan and rapid resistancedevelopment.MicroRNA(miRNA)-induced RNA interference is a promising approachfor pest control because of endogenous regulation of pest growth and development.Tosearch for miRNAs with potential insecticidal activity inP.citri,genome-wide analysis ofmiRNAs at different developmental stages was conducted,resulting in the identificationof 136 miRNAs,including 73 known and 63 novel miRNAs.A total of 17 isomiRNAsand 12 duplicated miRNAs were characterized.MiR-1 and miR-252-5p were identified asreference miRNAs forP.citriandTetranychus urticae.Based on differential expressionanalysis,treatments with miR-let-7a and miR-315 mimics and the miR-let-7a antagomirsignificantly reduced the egg hatch rate and resulted in abnormal egg development.Over-expression or downregulation of miR-34-5p and miR-305-5p through feeding significantlydecreased the adult eclosion rate and caused molting defects.The 4 miRNAs,miR-let-7a,miR-315,miR-34-5p,and miR-305-5p,had important regulatory functions and insectici-dal properties in egg hatching and adult eclosion.In general,these data advance our un-derstanding of miRNAs in mite biology,which can assist future studies on insect-specificmiRNA-based green pest control technology.
基金supported by the Science and Technology Basic Resources Investigation Program of China(2018FY101105)the National Natural Science Foundation of China(31972272,31871969)+1 种基金the Fundamental Research Funds for the Central Universities(SWU-XDPY22001)of Chinathe China Agricultural Research System of MOA and MARA.
文摘Insecticide resistance in Panonychus citri is a major obstacle to mite control in citrus orchards.Pyrethroid insecticides are continually used to control mites in China,although resistance to pyrethroids has evolved in some populations.Here,the resistance to the pyrethroid fenpropathrin was investigated and 7 out of 8 field-collected populations of P citri exhibited a high level of resistance,ranging from 171-fold to 15391-fold higher than the susceptible(SS)comparison strain.Three voltage-gated sodium channel(VGSC)mutations were identified in the tested populations:L1031V,F1747L,and F17511.Amplicon sequencing was used to evaluate the frequency of these mutations in the 19 field populations.L1031V and F1751I were present in all populations at frequencies of 11.6%-82.1%and 0.5%-31.8%,respectively,whereas the F1747L mutation was only present in 12 populations from Chongqing,Sichuan,Guangxi,and Yunnan provinces.Introduction of these mutations singly or in combination into transgenic flies significantly increased their resistance to fenpropathrin and these flies also exhibited reduced mortality after exposure to the pyrethroids permethrin andβ-cypermethrin.Panonychus citri VGSC homology modeling and ligand docking indicate that F1747 and F1751 form direct binding contacts with pyrethroids,which are lost with mutation,whereas L1031 mutation may diminish pyrethroid effects through an allosteric mechanism.Overall,the results provide molecular markers for monitoring pest resistance to pyrethroids and offer new insights into the basis of pyrethroid actions on sodium channels.
