Background Cotton(Gossypium spp.) is an important commercial crop being cultivated worldwide, but its production is hampered by many insect pests. The cotton aphid, Aphis gossypii Glover, is a key pest with increasing...Background Cotton(Gossypium spp.) is an important commercial crop being cultivated worldwide, but its production is hampered by many insect pests. The cotton aphid, Aphis gossypii Glover, is a key pest with increasing resistance to chemical insecticides. To explore eco-friendly management alternatives, this study evaluates the pathogenic potential of indigenous entomopathogenic fungi, isolated from cotton-growing regions of Tamil Nadu, India, via the ‘Galleria bait method'.Results Five entomopathogenic fungi were isolated and identified as Beauveria spp. based on cultural and morphological features. Molecular characterization by amplification of internal transcribed spacer-ribosomal DNA(ITS-rDNA) regions confirmed the isolates as B. bassiana. Among them, isolate B5(accession number: PP503009) exhibited the highest virulence, inducing 96.67% mortality at 7 days after treatment(DAT) with the concentration of 1 × 10^(8) spores·mL^(-1). The median lethal concentration(LC_(50)) and median lethal time(LT_(50)) values were 9.75 × 10^(4) spores·mL^(-1) at 7 DAT and 72.31 h at 1 × 10^(8) spores·mL^(-1), respectively. Scanning electron microscopy(SEM) images highlighted a progression of infection stages of B5, including spore attachment(24 h post infection(hpi)), hyphal penetration(48 hpi), and conidiogenesis(72 hpi).Conclusion The isolate B5 proved to be a promising candidate for the development of biopesticides for sustainable cotton aphid management in Tamil Nadu, India.展开更多
Background Aphis gossypii(Hemiptera:Aphididae)is a worldwide polyphagous phloem-feeding agricultural pest,and it can produce offspring by sexual or asexual reproduction.Compared with dozens of generations by parthenog...Background Aphis gossypii(Hemiptera:Aphididae)is a worldwide polyphagous phloem-feeding agricultural pest,and it can produce offspring by sexual or asexual reproduction.Compared with dozens of generations by parthenogenesis,sexual reproduction is performed in only one generation within one year,and little is known about the sexual reproduction of A.gossypii.In this study,sexual females of A.gossypii were successfully obtained through a previously established induction platform,and the morphological characteristics,developmental dynamics,and temporal gene expression were examined.Subsequently,signaling pathways potentially involved in regulating the growth,development,and reproduction of sexual females were investigated.Results The morphological observation showed that from the 1st instar nymph to adult,sexual females exhibited a gradually deepened body color,an enlarged body size,longer antennae with a blackened end,and obviously protruding cauda(in adulthood).The anatomy found that the ovaries of sexual females developed rapidly from the 2^(nd)instar nymph,and the embedded oocytes matured in adulthood.In addition,time-course transcriptome analysis revealed that gene expression profiles across the development of sexual females fell into 9 clusters with distinct patterns,in which gene expression levels in clusters 1,5,and 8 peaked at the 2^(nd)instar nymphal stage with the largest number of up-regulated genes,suggesting that the 2^(nd)instar nymph was an important ovary development period.Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis revealed that a large number of genes in the sexual female adult were enriched in the TGF-beta signaling pathway and Forkhead box O(FoxO)signaling pathway,highlighting their important role in sexual female adult development and reproduction.Conclusion The morphological changes of the sexual female at each developmental stage were revealed for the first time.In addition,time-course transcriptomic analyses suggest genes enriched in the TGF-beta signaling pathway and FoxO signaling pathway probably contribute to regulating the development and oocyte maturation of sexual females.Overall,these findings will facilitate the regulating mechanism research in the growth and development of sexual females by providing candidate genes.展开更多
Background:Aphis gossypii Glover(Hemiptera:Aphididae),a worldwide polyphagous phloem-feeding agricultural pest,has three wing morphs(winged parthenogenetic female,gynopara,and male)in the life cycle.The exclusive male...Background:Aphis gossypii Glover(Hemiptera:Aphididae),a worldwide polyphagous phloem-feeding agricultural pest,has three wing morphs(winged parthenogenetic female,gynopara,and male)in the life cycle.The exclusive males could fly from summer hosts to winter hosts,which are essential for gene exchanges of cotton aphid populations from different hosts or regions.However,the molecular mechanism of wing differentiation of male in A.gossypii remains unclear.Results:Morphological observation of male A.gossypii showed that there is no distinct difference in the external morphologies of the 1st and 2nd instar nymphs.The obvious differentiation of wing buds started in the 3rd instar nymph and was visible via naked eyes in the 4th instar nymphal stage,then adult male emerged with full wings.According to morphological dynamic changes,the development of wings in males were divided into four stages:preliminary stage(the 1st instar to 2nd instar),prophase(the 3rd instar),metaphase(the 4th instar),anaphase(the 5th instar).Results of feeding behavior monitoring via EPG(electrical penetration graph)technology indicated that although the male cotton aphids had strong desire to feed(longer duration of C 55.24%,F 5.05%and Pd waves 2.56%),its feeding efficiency to summer host cotton was low(shorter E13.56%and E2 waves 2.63%).Dynamic transcriptome analysis of male aphid at 5 different developmental periods showed that in the 3rd instar nymph,the number of up-regulated DEGs was significant increased,and time-course gene transcriptional pattern analyses results also showed that numerous genes categorized in clusters 3,5,and 8 had the highest expressed levels,which were consistent with morphological changes of wing buds.These results indicate that the 3rd instar nymph is the critical stage of wing bud differentiation in males.Furthermore,through pathway enrichment analysis of DEGs and WGCNA,it revealed that the neuroactive ligand-receptor interaction,Ras signaling pathway,dopaminergic synapse,circadian entrainment and the corresponding hub genes of PLK1,BUB1,SMC2,TUBG,ASPM,the kinesin family members(KIF23,KIF20,KIF18-19)and the novel subfamily of serine/threonine(Aurora kinase A and Aurora kinase B)probably played an important role in the critical stage of wing bud differentiation.Conclusion:This study explored morphological changes and genes transcriptional dynamics males in cotton aphid,revealed the phenomenon of low feeding efficiency of winged males on summer host cotton,and identified key signaling pathways and potential hub genes potentially involved in wing bud differentiation of male in A.gossypii.展开更多
文摘Background Cotton(Gossypium spp.) is an important commercial crop being cultivated worldwide, but its production is hampered by many insect pests. The cotton aphid, Aphis gossypii Glover, is a key pest with increasing resistance to chemical insecticides. To explore eco-friendly management alternatives, this study evaluates the pathogenic potential of indigenous entomopathogenic fungi, isolated from cotton-growing regions of Tamil Nadu, India, via the ‘Galleria bait method'.Results Five entomopathogenic fungi were isolated and identified as Beauveria spp. based on cultural and morphological features. Molecular characterization by amplification of internal transcribed spacer-ribosomal DNA(ITS-rDNA) regions confirmed the isolates as B. bassiana. Among them, isolate B5(accession number: PP503009) exhibited the highest virulence, inducing 96.67% mortality at 7 days after treatment(DAT) with the concentration of 1 × 10^(8) spores·mL^(-1). The median lethal concentration(LC_(50)) and median lethal time(LT_(50)) values were 9.75 × 10^(4) spores·mL^(-1) at 7 DAT and 72.31 h at 1 × 10^(8) spores·mL^(-1), respectively. Scanning electron microscopy(SEM) images highlighted a progression of infection stages of B5, including spore attachment(24 h post infection(hpi)), hyphal penetration(48 hpi), and conidiogenesis(72 hpi).Conclusion The isolate B5 proved to be a promising candidate for the development of biopesticides for sustainable cotton aphid management in Tamil Nadu, India.
基金funded by National Natural Science Foundation of China(No.32102214)Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences+1 种基金China Agriculture Research System(CARS-15-21)National Key R&D Program of China(2022YFD1400300)。
文摘Background Aphis gossypii(Hemiptera:Aphididae)is a worldwide polyphagous phloem-feeding agricultural pest,and it can produce offspring by sexual or asexual reproduction.Compared with dozens of generations by parthenogenesis,sexual reproduction is performed in only one generation within one year,and little is known about the sexual reproduction of A.gossypii.In this study,sexual females of A.gossypii were successfully obtained through a previously established induction platform,and the morphological characteristics,developmental dynamics,and temporal gene expression were examined.Subsequently,signaling pathways potentially involved in regulating the growth,development,and reproduction of sexual females were investigated.Results The morphological observation showed that from the 1st instar nymph to adult,sexual females exhibited a gradually deepened body color,an enlarged body size,longer antennae with a blackened end,and obviously protruding cauda(in adulthood).The anatomy found that the ovaries of sexual females developed rapidly from the 2^(nd)instar nymph,and the embedded oocytes matured in adulthood.In addition,time-course transcriptome analysis revealed that gene expression profiles across the development of sexual females fell into 9 clusters with distinct patterns,in which gene expression levels in clusters 1,5,and 8 peaked at the 2^(nd)instar nymphal stage with the largest number of up-regulated genes,suggesting that the 2^(nd)instar nymph was an important ovary development period.Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis revealed that a large number of genes in the sexual female adult were enriched in the TGF-beta signaling pathway and Forkhead box O(FoxO)signaling pathway,highlighting their important role in sexual female adult development and reproduction.Conclusion The morphological changes of the sexual female at each developmental stage were revealed for the first time.In addition,time-course transcriptomic analyses suggest genes enriched in the TGF-beta signaling pathway and FoxO signaling pathway probably contribute to regulating the development and oocyte maturation of sexual females.Overall,these findings will facilitate the regulating mechanism research in the growth and development of sexual females by providing candidate genes.
基金funded by National Natural Science Foundation of China(No.32102214)Special Fund for Basic Public Welfare Research of Institute of Cotton Research of CAAS(No.1610162020020604).
文摘Background:Aphis gossypii Glover(Hemiptera:Aphididae),a worldwide polyphagous phloem-feeding agricultural pest,has three wing morphs(winged parthenogenetic female,gynopara,and male)in the life cycle.The exclusive males could fly from summer hosts to winter hosts,which are essential for gene exchanges of cotton aphid populations from different hosts or regions.However,the molecular mechanism of wing differentiation of male in A.gossypii remains unclear.Results:Morphological observation of male A.gossypii showed that there is no distinct difference in the external morphologies of the 1st and 2nd instar nymphs.The obvious differentiation of wing buds started in the 3rd instar nymph and was visible via naked eyes in the 4th instar nymphal stage,then adult male emerged with full wings.According to morphological dynamic changes,the development of wings in males were divided into four stages:preliminary stage(the 1st instar to 2nd instar),prophase(the 3rd instar),metaphase(the 4th instar),anaphase(the 5th instar).Results of feeding behavior monitoring via EPG(electrical penetration graph)technology indicated that although the male cotton aphids had strong desire to feed(longer duration of C 55.24%,F 5.05%and Pd waves 2.56%),its feeding efficiency to summer host cotton was low(shorter E13.56%and E2 waves 2.63%).Dynamic transcriptome analysis of male aphid at 5 different developmental periods showed that in the 3rd instar nymph,the number of up-regulated DEGs was significant increased,and time-course gene transcriptional pattern analyses results also showed that numerous genes categorized in clusters 3,5,and 8 had the highest expressed levels,which were consistent with morphological changes of wing buds.These results indicate that the 3rd instar nymph is the critical stage of wing bud differentiation in males.Furthermore,through pathway enrichment analysis of DEGs and WGCNA,it revealed that the neuroactive ligand-receptor interaction,Ras signaling pathway,dopaminergic synapse,circadian entrainment and the corresponding hub genes of PLK1,BUB1,SMC2,TUBG,ASPM,the kinesin family members(KIF23,KIF20,KIF18-19)and the novel subfamily of serine/threonine(Aurora kinase A and Aurora kinase B)probably played an important role in the critical stage of wing bud differentiation.Conclusion:This study explored morphological changes and genes transcriptional dynamics males in cotton aphid,revealed the phenomenon of low feeding efficiency of winged males on summer host cotton,and identified key signaling pathways and potential hub genes potentially involved in wing bud differentiation of male in A.gossypii.
