The viruses titer and the ultrastructure of infected cells in tobacco host (Nicotiana tabacum cv. Samsun), which doubly infected with potato virus Y necrosis strain (PVYN) and potato virus X (PVX), were studied under ...The viruses titer and the ultrastructure of infected cells in tobacco host (Nicotiana tabacum cv. Samsun), which doubly infected with potato virus Y necrosis strain (PVYN) and potato virus X (PVX), were studied under greenhouse conditions. The results indicated that PVYN and PVX interacted synergistically. and tobacco plants which doubly infected with PVX and PVYN could greatly increase symptom severity as compared with that induced by the single virus. As determined by triple antibody sandwich enzyme-linked immunosor-bent assay (TAS-ELISA), the titer of PVX in the tobacco leaves infected with both PVYN and PVX was up to 9.10 times higher than the plants infected with PVX only. No significant differences in PVYN titer were detected between singly and doubly infected plants. The enhancement of PVX titer in doubly infected plants was evident in greenhouse and was independent of the virus strains, tested seasons, intervals between PVYN and PVX inoculation. When sections of doubly infected leaves were examined with an electron microscope, it could be frequently found that cells contained pinwheels and large masses of PVX-like particles, pinwheels and laminate inclusions, or all three structures, most of them were swollen, and their chloroplast and other organella were destructed heavily. This suggested that doubly infected cells were involved in the enhancement phenomenon, which seemed to be the result of an increase in the amount of PVX synthesized in them.展开更多
FT(Flowering locus T)基因是控制植物开花的关键基因,而PVX(Potato virus X)载体能够使外源基因在植物体内高水平瞬时表达。本文构建了拟南芥FT基因PVX病毒瞬时表达载体,通过农杆菌渗滤感染不同类型烟草品种,使拟南芥FT基因在烟草中瞬...FT(Flowering locus T)基因是控制植物开花的关键基因,而PVX(Potato virus X)载体能够使外源基因在植物体内高水平瞬时表达。本文构建了拟南芥FT基因PVX病毒瞬时表达载体,通过农杆菌渗滤感染不同类型烟草品种,使拟南芥FT基因在烟草中瞬时表达。结果表明,该系统能够诱导烤烟品种K326、云烟87和红花大金元,香料烟品种TEVB及白肋烟品种TN90早花,应用于烟草育种,可缩短育种进程。展开更多
To understand the effect of rare codon on the silencing ratio of foreign gene, some preferred codon in potato virus X (PVX) coat protein gene (cp) were substituted with synonymous rare codons. The modified PVX coat pr...To understand the effect of rare codon on the silencing ratio of foreign gene, some preferred codon in potato virus X (PVX) coat protein gene (cp) were substituted with synonymous rare codons. The modified PVX coat protein gene (cpm) and wild-type cp gene (cpw) were inserted into binary vector under the control of CaMV35S promoter, and these two plant expression constructs were transferred into tobacco (Nicotiana tabacum cv. Xanthi) genomes via Agrobacterium mediated method and transgenic plants were generated. Northern blot analysis of RNA isolated from these plants showed that the silencing ratio of cpm gene in transgenic tobaccos was higher than that of cpw (35% and 6.25% respectively). Run on results indicate that the silencing of cp gene happened at post-transcriptional level. The resistance of transgenic tobaccos carrying cpm genes to PVX is increased compared with that of transformants carrying cpw genes. These results suggest that the resistance of transgenic tobacco to PVX can be enhanced by codon replacement.展开更多
[Objective]The aim of this study was to identify transient expression of movement protein （MP） gene in Nicotinana benthaminana rapidly and further investigate the function of this exogenous gene. [Method]The movemen...[Objective]The aim of this study was to identify transient expression of movement protein （MP） gene in Nicotinana benthaminana rapidly and further investigate the function of this exogenous gene. [Method]The movement protein gene of barley yellow dwarf virus （BYDV） was cloned into potato virus X （PVX） viral vector of pGR107,and PVX-recombinant vector was obtained. After electroporation of Agrobacterium tumefaciens,PVX was inoculated into the lower leaves of tobacco by Agrobacterium infiltration assay to observe the infection of virus on tobacco. [Result]After infection for 7 days,upper non-inoculated leaves of tobacco infected by the PVX-recombinant vector showed the virus infection symptoms,while the control group had no viral infection phenomenon. Daily follow-up observations for two groups revealed that tobacco infected by PVX-recombinant vector had severe symptoms of virus infection and curling leaves,or even led to necrosis both in infiltrated and systemic leaves in late period. However,tobacco infected by PVX vector had only slight symptoms of virus infection and could recover from infection. RT-PCR of the infected tobacco indicated that exogenous gene BYDV-MP had a normal transcription and expression in tobacco. [Conclusion]As a determinant factor for viral disease,BYDV-MP promotes the systemic infection rate of PVX and its symptom. In addition,it is feasible to express exogenous MP gene in Nicotiana benthaminan via PVX expression vector.展开更多
基金This project was supported by the National Natu ral Science Foundation of China(30100117)China Postdoctoral Science Foundation(2002031168)the Key Task of Shandong Provincial Scientific Foundation and Technological Department(981020171),China.
文摘The viruses titer and the ultrastructure of infected cells in tobacco host (Nicotiana tabacum cv. Samsun), which doubly infected with potato virus Y necrosis strain (PVYN) and potato virus X (PVX), were studied under greenhouse conditions. The results indicated that PVYN and PVX interacted synergistically. and tobacco plants which doubly infected with PVX and PVYN could greatly increase symptom severity as compared with that induced by the single virus. As determined by triple antibody sandwich enzyme-linked immunosor-bent assay (TAS-ELISA), the titer of PVX in the tobacco leaves infected with both PVYN and PVX was up to 9.10 times higher than the plants infected with PVX only. No significant differences in PVYN titer were detected between singly and doubly infected plants. The enhancement of PVX titer in doubly infected plants was evident in greenhouse and was independent of the virus strains, tested seasons, intervals between PVYN and PVX inoculation. When sections of doubly infected leaves were examined with an electron microscope, it could be frequently found that cells contained pinwheels and large masses of PVX-like particles, pinwheels and laminate inclusions, or all three structures, most of them were swollen, and their chloroplast and other organella were destructed heavily. This suggested that doubly infected cells were involved in the enhancement phenomenon, which seemed to be the result of an increase in the amount of PVX synthesized in them.
文摘FT(Flowering locus T)基因是控制植物开花的关键基因,而PVX(Potato virus X)载体能够使外源基因在植物体内高水平瞬时表达。本文构建了拟南芥FT基因PVX病毒瞬时表达载体,通过农杆菌渗滤感染不同类型烟草品种,使拟南芥FT基因在烟草中瞬时表达。结果表明,该系统能够诱导烤烟品种K326、云烟87和红花大金元,香料烟品种TEVB及白肋烟品种TN90早花,应用于烟草育种,可缩短育种进程。
基金supported by the National Key Basic Research Project(Grant No.G2000016205)the National Natura1 Science Foundation of China(Grant No.39989001)
文摘To understand the effect of rare codon on the silencing ratio of foreign gene, some preferred codon in potato virus X (PVX) coat protein gene (cp) were substituted with synonymous rare codons. The modified PVX coat protein gene (cpm) and wild-type cp gene (cpw) were inserted into binary vector under the control of CaMV35S promoter, and these two plant expression constructs were transferred into tobacco (Nicotiana tabacum cv. Xanthi) genomes via Agrobacterium mediated method and transgenic plants were generated. Northern blot analysis of RNA isolated from these plants showed that the silencing ratio of cpm gene in transgenic tobaccos was higher than that of cpw (35% and 6.25% respectively). Run on results indicate that the silencing of cp gene happened at post-transcriptional level. The resistance of transgenic tobaccos carrying cpm genes to PVX is increased compared with that of transformants carrying cpw genes. These results suggest that the resistance of transgenic tobacco to PVX can be enhanced by codon replacement.
基金Supported by National Natural Science Foundation of China(30870109)~~
文摘[Objective]The aim of this study was to identify transient expression of movement protein （MP） gene in Nicotinana benthaminana rapidly and further investigate the function of this exogenous gene. [Method]The movement protein gene of barley yellow dwarf virus （BYDV） was cloned into potato virus X （PVX） viral vector of pGR107,and PVX-recombinant vector was obtained. After electroporation of Agrobacterium tumefaciens,PVX was inoculated into the lower leaves of tobacco by Agrobacterium infiltration assay to observe the infection of virus on tobacco. [Result]After infection for 7 days,upper non-inoculated leaves of tobacco infected by the PVX-recombinant vector showed the virus infection symptoms,while the control group had no viral infection phenomenon. Daily follow-up observations for two groups revealed that tobacco infected by PVX-recombinant vector had severe symptoms of virus infection and curling leaves,or even led to necrosis both in infiltrated and systemic leaves in late period. However,tobacco infected by PVX vector had only slight symptoms of virus infection and could recover from infection. RT-PCR of the infected tobacco indicated that exogenous gene BYDV-MP had a normal transcription and expression in tobacco. [Conclusion]As a determinant factor for viral disease,BYDV-MP promotes the systemic infection rate of PVX and its symptom. In addition,it is feasible to express exogenous MP gene in Nicotiana benthaminan via PVX expression vector.
