[Objective]The aim was to construct the wheat heat-shock protein 60 （HSP60） gene in prokaryotic expression vector and express HSP60 efficiently in E.coli. [Method]According to the wheat HSP60 gene sequence in GenBank,a pair of primers P1/P2 were designed and synthesized. The wheat HSP60 gene fragment was amplified from the wheat RNA by RT-PCR and inserted into bacterial expression vector of pGEX-4T-1. The construct of pGEX-4T-1-HSP60 was subsequently transformed into E.coli BL21. [Result]The construct of pGEX-4T-1-HSP60 was verified by restriction endonuclease digestion and sequenced. Compared with the sequences of wheat HSP60 genes in GenBank,homology accounted to 100%. Expression of the GST-HSP60 fusion protein was induced with IPTG. Its molecular weight was about 90 kD. The result was identified by electrophoresis of SDS-PAGE. Expression of the protein bands was consistent with the expected size. [Conclusion]The recombinant prokaryotic expression vector in pGEX-4T-1-HSP60 was constructed successfully and expressed stably in E.coli BL21. This will lay the foundation for further study on the functions of the protein and its mechanism.
[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.
