The two-spotted spider mite,Tetranychus urticae Koch,is one of the most harmful pests in many agroecosystems worldwide.To effectively manage this pest,there is an urgent need to develop novel bio-active acaricides tha...The two-spotted spider mite,Tetranychus urticae Koch,is one of the most harmful pests in many agroecosystems worldwide.To effectively manage this pest,there is an urgent need to develop novel bio-active acaricides that support integrated pest management strategies targeting T.urticae.In this study,we explored the acaricidal effects of xenocoumacin 1 (Xcn1) on T.urticae and its predator Neoseiulus californicus using the highly puri?ed compound.Xcn1 was extracted and purified from the cell-free supernatant of the Xenorhabdus nematophila CB6 mutant constructed by the easy promoter activated compound identi?cation (easyPACId) method.When the concentration of Xcn1 exceeded 100μg mL~(–1),the survival rate of spider mite adults declined to below 40%and the fecundity was decreased by 80%at six days post-application.At concentrations of 25 and 50μg mL~(–1),Xcn1 signi?cantly impeded spider mite development by inhibiting the molt.However,neither concentration had any adverse effects on the survival or reproduction of the predatory mite N.californicus.The results from laboratory and semi-?eld experiments consistently demonstrated the effectiveness of the antimicrobial metabolite Xcn1 in controlling pest mites at both the molecular and physiological levels.Our study offers a promising possibility that combines the compatible biocontrol agents of Xcn1 and predatory mites for integrated pest mite control.展开更多
This research aims to develop a non-invasive strategy for small interfering RNA(siRNA)nasal delivery based on ionic liquids(ILs)and cationic lipid(2,3-dioleoyloxy-propyl)-trimethylammonium-chloride(DOTAP).Other than t...This research aims to develop a non-invasive strategy for small interfering RNA(siRNA)nasal delivery based on ionic liquids(ILs)and cationic lipid(2,3-dioleoyloxy-propyl)-trimethylammonium-chloride(DOTAP).Other than the classical role of penetration enhancer,ILs also acted as superior solvents to simultaneously load siRNA and DOTAP,forming siRNA-DOTAP-ILs(siRNA-DILs)formulations.During nasal mucosa penetration,DOTAP and ILs components self-assembled into cationic lipid nanocomplexes to load siRNA for enhanced in situ transfection.The siRNA-DILs demonstrated resistance against RNase,significant mucosa penetration,prolonged nasal retention,and satisfying gene-silencing efficacy at lower dosage.Meanwhile,DILs were also able to deliver KCa3.1-targeted siRNA effectively for the treatment of allergic rhinitis in rat model by nasal route.Thus,DILs have great potentials to deliver biological macromolecules across nasal mucosa by in situ dynamic self-assembly.展开更多
Fusarium graminearum,the primary pathogenic fungus responsible for Fusarium head blight(FHB)in wheat,secretes abundant chemical compounds that interact with host plants.In this study,a secreted protein FgHrip1,isolate...Fusarium graminearum,the primary pathogenic fungus responsible for Fusarium head blight(FHB)in wheat,secretes abundant chemical compounds that interact with host plants.In this study,a secreted protein FgHrip1,isolated from the culture filtrate of F.graminearum,was found to induce typical cell death in tobacco.The FgHrip1 gene was then cloned and expressed in Escherichia coli.Further bioassay analysis showed that the recombinant FgHrip1 induced early defense induction events,such as reactive oxygen species(ROS)production,callose deposition,and up-regulation of defense-related genes in tobacco.Furthermore,FgHrip1 significantly enhanced immunity in tobacco seedlings against Pseudomonas syringae pv.tabaci 6605(Pst.6605)and tobacco mosaic virus(TMV).FgHrip1-treated wheat spikes also exhibited defense-related transcript accumulation and developed immunity against FHB infection.Whereas the expression of FgHrip1 was induced during the infection process,the deletion of the gene impaired the virulence of F.graminearum.Our results suggest that FgHrip1triggers immunity and induces disease resistance in tobacco and wheat,thereby providing new insight into strategy for biocontrol of FHB.展开更多
基金supported by the National Natural Science Foundation of China(32070402)the Beijing Natural Science Foundation,China(6222052)。
文摘The two-spotted spider mite,Tetranychus urticae Koch,is one of the most harmful pests in many agroecosystems worldwide.To effectively manage this pest,there is an urgent need to develop novel bio-active acaricides that support integrated pest management strategies targeting T.urticae.In this study,we explored the acaricidal effects of xenocoumacin 1 (Xcn1) on T.urticae and its predator Neoseiulus californicus using the highly puri?ed compound.Xcn1 was extracted and purified from the cell-free supernatant of the Xenorhabdus nematophila CB6 mutant constructed by the easy promoter activated compound identi?cation (easyPACId) method.When the concentration of Xcn1 exceeded 100μg mL~(–1),the survival rate of spider mite adults declined to below 40%and the fecundity was decreased by 80%at six days post-application.At concentrations of 25 and 50μg mL~(–1),Xcn1 signi?cantly impeded spider mite development by inhibiting the molt.However,neither concentration had any adverse effects on the survival or reproduction of the predatory mite N.californicus.The results from laboratory and semi-?eld experiments consistently demonstrated the effectiveness of the antimicrobial metabolite Xcn1 in controlling pest mites at both the molecular and physiological levels.Our study offers a promising possibility that combines the compatible biocontrol agents of Xcn1 and predatory mites for integrated pest mite control.
基金supported by National Natural Science Foundation of China(No.82073801)。
文摘This research aims to develop a non-invasive strategy for small interfering RNA(siRNA)nasal delivery based on ionic liquids(ILs)and cationic lipid(2,3-dioleoyloxy-propyl)-trimethylammonium-chloride(DOTAP).Other than the classical role of penetration enhancer,ILs also acted as superior solvents to simultaneously load siRNA and DOTAP,forming siRNA-DOTAP-ILs(siRNA-DILs)formulations.During nasal mucosa penetration,DOTAP and ILs components self-assembled into cationic lipid nanocomplexes to load siRNA for enhanced in situ transfection.The siRNA-DILs demonstrated resistance against RNase,significant mucosa penetration,prolonged nasal retention,and satisfying gene-silencing efficacy at lower dosage.Meanwhile,DILs were also able to deliver KCa3.1-targeted siRNA effectively for the treatment of allergic rhinitis in rat model by nasal route.Thus,DILs have great potentials to deliver biological macromolecules across nasal mucosa by in situ dynamic self-assembly.
基金financed by the National Key Research and Development Program of China(2017YFD0200900)。
文摘Fusarium graminearum,the primary pathogenic fungus responsible for Fusarium head blight(FHB)in wheat,secretes abundant chemical compounds that interact with host plants.In this study,a secreted protein FgHrip1,isolated from the culture filtrate of F.graminearum,was found to induce typical cell death in tobacco.The FgHrip1 gene was then cloned and expressed in Escherichia coli.Further bioassay analysis showed that the recombinant FgHrip1 induced early defense induction events,such as reactive oxygen species(ROS)production,callose deposition,and up-regulation of defense-related genes in tobacco.Furthermore,FgHrip1 significantly enhanced immunity in tobacco seedlings against Pseudomonas syringae pv.tabaci 6605(Pst.6605)and tobacco mosaic virus(TMV).FgHrip1-treated wheat spikes also exhibited defense-related transcript accumulation and developed immunity against FHB infection.Whereas the expression of FgHrip1 was induced during the infection process,the deletion of the gene impaired the virulence of F.graminearum.Our results suggest that FgHrip1triggers immunity and induces disease resistance in tobacco and wheat,thereby providing new insight into strategy for biocontrol of FHB.
