A chimeric gene, Bt29K, composed of coding sequences of activated Cry1Ac insecticidal protein and an endoplasm reticulum-retarding signal peptide, was synthesized. A plant expression vector containing two expression c...A chimeric gene, Bt29K, composed of coding sequences of activated Cry1Ac insecticidal protein and an endoplasm reticulum-retarding signal peptide, was synthesized. A plant expression vector containing two expression cassettes for the Bt29K and API-B genes was constructed. These two insect-resistant genes were transferred into two cotton ( Gossypium hirsutum L.) varieties ( or lines) via Agrobacterium-mediated transformation and nine homozygous transgenic cotton lines showing a mortality of 90.0% - 99.7% to cotton ballworm (Heliothis armigera) larvae and good agronomic traits were selected through six generations. Molecular biology analysis revealed that one or two copies of the insecticidal protein genes were integrated into the transgenic cotton genome and activated Cry1Ac and API-B protein expression was at a level of 0.17% and 0.09% of the total soluble protein in the transgenic cotton leaves, respectively. Comparison of the insect-resistance of the homozygous lines expressing the activated chimeric Cry1Ac and API-B with that expressing Cry1Ac only revealed that the insect-resistance of the former is apparently higher than the latter. These results also indicate that the strategy to construct a plant expression vector expressing two different insect-resistant genes reported here is reasonable.展开更多
Transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis(Bt)have proven to be highly effective in managing some key pests.However,the evolution of resistance by the target pests threa...Transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis(Bt)have proven to be highly effective in managing some key pests.However,the evolution of resistance by the target pests threatens the sustainability of Bt crops.The L31S mutation in a tetraspanin encoded by Harm TspC5(previously known as Ha TSPAN1)has been shown to confer dominant resistance to the Bt protein Cry1Ac in Helicoverpa armigera,a globally damaging lepidopteran pest.However,the broader implications of the L31S mutation in the tetraspanins of other lepidopteran species remain unclear.The evolutionary analyses in this study indicate that TspC5s have evolved in a species-specific manner among the lepidopteran insects.To investigate the role of TspC5s in conferring dominant resistance to Cry1Ac,we used the piggyBac-based transformation system to generate four transgenic H.armigera strains that express exogenous TspC5 variants from three phylogenetically close species(Helicoverpa zea,Helicoverpa assulta and Heliothis virescens)and one phylogenetically distant species(Plutella xylostella).In comparison with the background SCD strain of H.armigera,the transgenic strains expressing HzeaTspC5-L31S,HassTspC5-L31S,or HvirTspC5-L31S exhibited significant resistance to Cry1Ac(10.0-,21.4-,and 81.1-fold,respectively),whereas the strain expressing PxylTspC5-L27S remained susceptible.Furthermore,the Cry1Ac resistant phenotypes followed an autosomal dominant inheritance pattern and were closely linked to the introduced mutant TspC5s.These findings reveal the conserved role of TspC5s from Helicoverpa and Heliothis species in mediating the dominant resistance to Cry1Ac,and they provide crucial insights for assessing resistance risks related to mutant tetraspanins and devising adaptive resistance management strategies for these major lepidopteran pests.展开更多
Seed priming is an effective seed pretreatment technology that enhances germination and overall crop performance by optimizing seed hydration and metabolic processes before planting.Seed quality is a critical determin...Seed priming is an effective seed pretreatment technology that enhances germination and overall crop performance by optimizing seed hydration and metabolic processes before planting.Seed quality is a critical determinant of cotton(Gossypium hirsutum)crop performance,influencing germination,plant vigor,and yield.This study evaluates the effects of seed priming with potassium salts(1%and 2%KCl and K2SO4)on germination,morphological traits,and Cry1Ac gene expression in three Bt cotton cultivars(IUB-2013,NIAB-878B,FH-142)as Cry1Ac enhance the pest resistance in Bt cotton and reduce the plant’s dependence on chemical insecticides.Seeds were primed for six hours,air-dried,and sown in the field.Germination rates,plant height,number of bolls per plant,boll weight,seed cotton yield,and ginning outturn(GOT)were assessed at crop maturity.Cry1Ac gene expression was quantified to explore the influence of priming treatments on transgene activity.Results demonstrated that 1%K2SO4 priming significantly enhanced germination and yield-related traits,with Cry1Ac expression peaking in the IUB-2013 cultivar under 1%K2SO4 treatment.These findings suggest that potassium-based halopriming improves cotton seedling establishment and Bt gene expression.This study addresses the critical gaps in understanding the effects of seed halopriming on morphological traits,germination,and expression of the Cry1Ac gene in Bt cotton while providing a novel eco-friendly and cost-effective halopriming approach,offering the potential to improve cotton production.展开更多
肺炎支原体(Mycoplasma pneumoniae)是儿童和成人最常见的呼吸道感染病原体。临床观察肺炎支原体感染会引起呼吸道黏液大量分泌,给患者呼吸造成困难,已有研究表明肺炎支原体感染会引起大量黏蛋白5AC(mucin 5AC,MUC5AC)的分泌。肺炎支原...肺炎支原体(Mycoplasma pneumoniae)是儿童和成人最常见的呼吸道感染病原体。临床观察肺炎支原体感染会引起呼吸道黏液大量分泌,给患者呼吸造成困难,已有研究表明肺炎支原体感染会引起大量黏蛋白5AC(mucin 5AC,MUC5AC)的分泌。肺炎支原体P1黏附素通过介导病原体与宿主细胞的黏附在肺炎支原体感染的发病机制中发挥重要作用,其中P1的C-末端残基(P1-C)具有免疫原性。本研究探讨了Wnt(Wingless,Wnt)/β-catenin信号通路抑制因子Dickkopf-1(Dickkopf-1,DKK1)在肺炎支原体P1-C诱导的肺上皮细胞分泌黏蛋白MUC5AC的分子机制。利用扫描电镜(scanning electron microscope,SEM)、苏木精-伊红(hematoxylin-eosin,HE)染色观察肺炎支原体P1-C对小鼠肺上皮细胞(mouse airway epithelial cells,MAECs)黏液分泌的影响;利用蛋白芯片技术检测肺炎支原体P1-C对小鼠气道上皮细胞炎症因子分泌及对相关信号通路的富集分析;采用糖原染色(periodic acid schiff stain,PAS)、Tunel染色、Masson染色检测肺炎支原体P1-C对小鼠肺的损伤情况;采用免疫组化检测黏蛋白MUC5AC的分泌情况,采用蛋白免疫印迹检测DKK1调控肺炎支原体P1-C蛋白诱导小鼠肺上皮细胞分泌黏蛋白MUC5AC的分子机制。结果表明,肺炎支原体P1-C能够引起小鼠原代上皮细胞大量黏液和炎性因子的分泌,在肺炎支原体P1-C感染中,DKK1能下调JAK激酶2(janus kinase 2,JAK2)、磷酸化信号传导与转录激活因子1(phosphorylation signal transducer and activator of transcription 1,p-STAT1)和磷酸化信号传导与转录激活因子3(phosphorylation signal transducer and activator of transcription 3,p-STAT3)蛋白的表达;同时,DKK1过表达显著上调MUC5AC抑制转录因子叉头框蛋白A2(fork-head box A2,FOXA2)的表达,从而显著抑制了肺炎支原体P1-C诱导的MUC5AC的表达。通过该研究推测DKK1通过抑制JAK/STAT1-STAT3信号通路以及上调FOXA2的表达有效地减少肺炎支原体P1-C诱导的小鼠肺上皮细胞MUC5AC的分泌。展开更多
文摘A chimeric gene, Bt29K, composed of coding sequences of activated Cry1Ac insecticidal protein and an endoplasm reticulum-retarding signal peptide, was synthesized. A plant expression vector containing two expression cassettes for the Bt29K and API-B genes was constructed. These two insect-resistant genes were transferred into two cotton ( Gossypium hirsutum L.) varieties ( or lines) via Agrobacterium-mediated transformation and nine homozygous transgenic cotton lines showing a mortality of 90.0% - 99.7% to cotton ballworm (Heliothis armigera) larvae and good agronomic traits were selected through six generations. Molecular biology analysis revealed that one or two copies of the insecticidal protein genes were integrated into the transgenic cotton genome and activated Cry1Ac and API-B protein expression was at a level of 0.17% and 0.09% of the total soluble protein in the transgenic cotton leaves, respectively. Comparison of the insect-resistance of the homozygous lines expressing the activated chimeric Cry1Ac and API-B with that expressing Cry1Ac only revealed that the insect-resistance of the former is apparently higher than the latter. These results also indicate that the strategy to construct a plant expression vector expressing two different insect-resistant genes reported here is reasonable.
基金primarily funded by a grant from the National Natural Science Foundation of China(31930093)Additional support was provided by the Natural Science Foundation of Jiangsu Province,China(BK20230983)the Project of Fund for Stable Support to Agricultural Sci-Tech Renovation,China(xjnkywdzc-2022004)。
文摘Transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis(Bt)have proven to be highly effective in managing some key pests.However,the evolution of resistance by the target pests threatens the sustainability of Bt crops.The L31S mutation in a tetraspanin encoded by Harm TspC5(previously known as Ha TSPAN1)has been shown to confer dominant resistance to the Bt protein Cry1Ac in Helicoverpa armigera,a globally damaging lepidopteran pest.However,the broader implications of the L31S mutation in the tetraspanins of other lepidopteran species remain unclear.The evolutionary analyses in this study indicate that TspC5s have evolved in a species-specific manner among the lepidopteran insects.To investigate the role of TspC5s in conferring dominant resistance to Cry1Ac,we used the piggyBac-based transformation system to generate four transgenic H.armigera strains that express exogenous TspC5 variants from three phylogenetically close species(Helicoverpa zea,Helicoverpa assulta and Heliothis virescens)and one phylogenetically distant species(Plutella xylostella).In comparison with the background SCD strain of H.armigera,the transgenic strains expressing HzeaTspC5-L31S,HassTspC5-L31S,or HvirTspC5-L31S exhibited significant resistance to Cry1Ac(10.0-,21.4-,and 81.1-fold,respectively),whereas the strain expressing PxylTspC5-L27S remained susceptible.Furthermore,the Cry1Ac resistant phenotypes followed an autosomal dominant inheritance pattern and were closely linked to the introduced mutant TspC5s.These findings reveal the conserved role of TspC5s from Helicoverpa and Heliothis species in mediating the dominant resistance to Cry1Ac,and they provide crucial insights for assessing resistance risks related to mutant tetraspanins and devising adaptive resistance management strategies for these major lepidopteran pests.
基金National Natural Science Foundation of China(3216045632360474+2 种基金32360486)grants from the Provincial Basic Research Program(Natural Science)([2020]1Z018)Provincial Key Technology R&D Program([2021]YiBan272).
文摘Seed priming is an effective seed pretreatment technology that enhances germination and overall crop performance by optimizing seed hydration and metabolic processes before planting.Seed quality is a critical determinant of cotton(Gossypium hirsutum)crop performance,influencing germination,plant vigor,and yield.This study evaluates the effects of seed priming with potassium salts(1%and 2%KCl and K2SO4)on germination,morphological traits,and Cry1Ac gene expression in three Bt cotton cultivars(IUB-2013,NIAB-878B,FH-142)as Cry1Ac enhance the pest resistance in Bt cotton and reduce the plant’s dependence on chemical insecticides.Seeds were primed for six hours,air-dried,and sown in the field.Germination rates,plant height,number of bolls per plant,boll weight,seed cotton yield,and ginning outturn(GOT)were assessed at crop maturity.Cry1Ac gene expression was quantified to explore the influence of priming treatments on transgene activity.Results demonstrated that 1%K2SO4 priming significantly enhanced germination and yield-related traits,with Cry1Ac expression peaking in the IUB-2013 cultivar under 1%K2SO4 treatment.These findings suggest that potassium-based halopriming improves cotton seedling establishment and Bt gene expression.This study addresses the critical gaps in understanding the effects of seed halopriming on morphological traits,germination,and expression of the Cry1Ac gene in Bt cotton while providing a novel eco-friendly and cost-effective halopriming approach,offering the potential to improve cotton production.
文摘肺炎支原体(Mycoplasma pneumoniae)是儿童和成人最常见的呼吸道感染病原体。临床观察肺炎支原体感染会引起呼吸道黏液大量分泌,给患者呼吸造成困难,已有研究表明肺炎支原体感染会引起大量黏蛋白5AC(mucin 5AC,MUC5AC)的分泌。肺炎支原体P1黏附素通过介导病原体与宿主细胞的黏附在肺炎支原体感染的发病机制中发挥重要作用,其中P1的C-末端残基(P1-C)具有免疫原性。本研究探讨了Wnt(Wingless,Wnt)/β-catenin信号通路抑制因子Dickkopf-1(Dickkopf-1,DKK1)在肺炎支原体P1-C诱导的肺上皮细胞分泌黏蛋白MUC5AC的分子机制。利用扫描电镜(scanning electron microscope,SEM)、苏木精-伊红(hematoxylin-eosin,HE)染色观察肺炎支原体P1-C对小鼠肺上皮细胞(mouse airway epithelial cells,MAECs)黏液分泌的影响;利用蛋白芯片技术检测肺炎支原体P1-C对小鼠气道上皮细胞炎症因子分泌及对相关信号通路的富集分析;采用糖原染色(periodic acid schiff stain,PAS)、Tunel染色、Masson染色检测肺炎支原体P1-C对小鼠肺的损伤情况;采用免疫组化检测黏蛋白MUC5AC的分泌情况,采用蛋白免疫印迹检测DKK1调控肺炎支原体P1-C蛋白诱导小鼠肺上皮细胞分泌黏蛋白MUC5AC的分子机制。结果表明,肺炎支原体P1-C能够引起小鼠原代上皮细胞大量黏液和炎性因子的分泌,在肺炎支原体P1-C感染中,DKK1能下调JAK激酶2(janus kinase 2,JAK2)、磷酸化信号传导与转录激活因子1(phosphorylation signal transducer and activator of transcription 1,p-STAT1)和磷酸化信号传导与转录激活因子3(phosphorylation signal transducer and activator of transcription 3,p-STAT3)蛋白的表达;同时,DKK1过表达显著上调MUC5AC抑制转录因子叉头框蛋白A2(fork-head box A2,FOXA2)的表达,从而显著抑制了肺炎支原体P1-C诱导的MUC5AC的表达。通过该研究推测DKK1通过抑制JAK/STAT1-STAT3信号通路以及上调FOXA2的表达有效地减少肺炎支原体P1-C诱导的小鼠肺上皮细胞MUC5AC的分泌。
