The stylet penetration behavior of aphids when feeding on plants is associated with virus acquisition and inoculation.Aphidius gifuensis (Ashmead)is a primary endoparasitoid of Myzuspersicae (Sulzer)which is the most ...The stylet penetration behavior of aphids when feeding on plants is associated with virus acquisition and inoculation.Aphidius gifuensis (Ashmead)is a primary endoparasitoid of Myzuspersicae (Sulzer)which is the most efficient vector of plant viruses. Information about the effects ofparasitoid on aphid and virus transmission can provide an essential foundation for designing effective biological control strategies.This study aimed to investigate the effects ofA.gifuensis on the feeding behavior and potato virus Y (PVY) transmission ability of M.persicae.The results showed that after M.persicae was para-sitized by A.gifuensis,the duration of the first probe significantly decreased.Additionally, A.gifuensis exerted remarkable effects on aphid feeding in phloem ingestion.The contribution of the E1 waveform to the phloem phase was significantly higher in all parasitized aphids than in the control group.Although the time of infestation increased for parasitized aphids,the total duration of phloem sap ingestion decreased.Interestingly,the percentage of time M.persicae spent in the xylem and phloem phases only changed significantly on day 5.The percent transmission of PVY by the aphids parasitized on day 5 was lower than that in the control,but no significant differences were detected.The significance of this work is the demonstration that A.gifuensis can impede the feeding behavior of M.persicae,which sheds light on the biological basis ofA.gifuensis as a natural enemy, but unfortunately does not provide an immediate solution for disrupting the transmission of PVY.展开更多
Sap-sucking insects often transmit plant viruses but also carry insect viruses,which infect insects but not plants.The impact of such insect viruses on insect host biology and ecology is largely unknown.Here,we identi...Sap-sucking insects often transmit plant viruses but also carry insect viruses,which infect insects but not plants.The impact of such insect viruses on insect host biology and ecology is largely unknown.Here,we identified a novel insect-specific virus carried by brown citrus aphid(Aphis citricidus),which we tentatively named Aphis citricidus picornavirus(AcPV).Phylogenetic analysis discovered a monophyletic cluster with AcPV and other unassigned viruses,suggesting that these viruses represent a new family in order Picornavirales.Systemic infection with AcPV triggered aphid antiviral immunity mediated by RNA interference,resulting in asymptomatic tolerance.Importantly,we found that AcPV was transmitted horizontally by secretion of the salivary gland into the feeding sites of plants.AcPV influenced aphid stylet behavior during feeding and increased the time required for intercellular penetration,thus promoting its transmission among aphids with plants as an intermediate site.The gene expression results suggested that this mechanism was linked with transcription of salivary protein genes and plant defense hormone signaling.Together,our results show that the horizontal transmission of AcPV in brown citrus aphids evolved in a manner similar to that of the circulative transmission of plant viruses by insect vectors,thus providing a new ecological perspective on the activity of insect-specific viruses found in aphids and improving the understanding of insect virus ecology.展开更多
文摘The stylet penetration behavior of aphids when feeding on plants is associated with virus acquisition and inoculation.Aphidius gifuensis (Ashmead)is a primary endoparasitoid of Myzuspersicae (Sulzer)which is the most efficient vector of plant viruses. Information about the effects ofparasitoid on aphid and virus transmission can provide an essential foundation for designing effective biological control strategies.This study aimed to investigate the effects ofA.gifuensis on the feeding behavior and potato virus Y (PVY) transmission ability of M.persicae.The results showed that after M.persicae was para-sitized by A.gifuensis,the duration of the first probe significantly decreased.Additionally, A.gifuensis exerted remarkable effects on aphid feeding in phloem ingestion.The contribution of the E1 waveform to the phloem phase was significantly higher in all parasitized aphids than in the control group.Although the time of infestation increased for parasitized aphids,the total duration of phloem sap ingestion decreased.Interestingly,the percentage of time M.persicae spent in the xylem and phloem phases only changed significantly on day 5.The percent transmission of PVY by the aphids parasitized on day 5 was lower than that in the control,but no significant differences were detected.The significance of this work is the demonstration that A.gifuensis can impede the feeding behavior of M.persicae,which sheds light on the biological basis ofA.gifuensis as a natural enemy, but unfortunately does not provide an immediate solution for disrupting the transmission of PVY.
基金This research was supported by the National Natural Science Foundation of China(32072423).
文摘Sap-sucking insects often transmit plant viruses but also carry insect viruses,which infect insects but not plants.The impact of such insect viruses on insect host biology and ecology is largely unknown.Here,we identified a novel insect-specific virus carried by brown citrus aphid(Aphis citricidus),which we tentatively named Aphis citricidus picornavirus(AcPV).Phylogenetic analysis discovered a monophyletic cluster with AcPV and other unassigned viruses,suggesting that these viruses represent a new family in order Picornavirales.Systemic infection with AcPV triggered aphid antiviral immunity mediated by RNA interference,resulting in asymptomatic tolerance.Importantly,we found that AcPV was transmitted horizontally by secretion of the salivary gland into the feeding sites of plants.AcPV influenced aphid stylet behavior during feeding and increased the time required for intercellular penetration,thus promoting its transmission among aphids with plants as an intermediate site.The gene expression results suggested that this mechanism was linked with transcription of salivary protein genes and plant defense hormone signaling.Together,our results show that the horizontal transmission of AcPV in brown citrus aphids evolved in a manner similar to that of the circulative transmission of plant viruses by insect vectors,thus providing a new ecological perspective on the activity of insect-specific viruses found in aphids and improving the understanding of insect virus ecology.
