Preliminary Study Of Tobacco Nb Spd Gene Function In BaMV Infection

BaMV(Bamboo mosaic virus),a virus mainly infects bamboos,is the member of Potexviurs belonging to Alphaflexiviridae,and it is the only member in Potexvirus that associated with satellite RNA.After BaMV infection,bamboo leaves showed stripe mosaic and reduced shooting ratio,the bamboo internodes also will be getting short.Therefore,the BaMV infection will seriously impact the yield and quality of bamboo,and spawned a great number of economic losses of the bamboo industry.The genome of BaMV is single-stranded RNA,and its full length is 6366 nucleotides(not include poly(A)),it coding 5 proteins,which are replicase,TGBp1,TGBp2,TGBp3 and CP.Early study of our laboratory used TGBp1 as a bait protein,screened tobacco library,in these obtained proteins,there is a protein coded by Nb spermidine synthase(Nb Spd).The protein coded by Nb Spd is a spermidine synthase,and spermidine is a kind of polyamine,that is a organic small molecular substances with physiological activity general exist inside plant.This kind of physiological active substances is closely related to the plant growth and development and adversity stress resistance of plant,strengthening metabolic activity of polyamine can enhance general adversity resistance of the plant.So,this study chooses the methods such as Real-time fluorescence quantitative PCR(RT-qPCR),VIGS,BIFC and so on,to research the function of Nb Spd during BaMV infection and replication.Results are as follows:1.After BaMV infectious clone injection,we used the qRT-PCR to test the expression of Nb Spd and we found it has risen 2.3 times than control in system leaf in 7dpi;We use TRV vector to interfere the expression of Nb Spd,and 7d after interference,we found the Nb Spd gene showed a 5 times down-regulated expression to the control.2.Constructed pEarleyGate201-YC,pEarleyGate202-YN vector of some components such as TGBp1,CP,Helicase,Capping and Nb Spd,use BiFC to observe the interaction between each pair of these components.The result identify the interactions between Nb Spd and TGBp1,CP,Helicase,Capping respectively are existent.3.Prepared the polyclonal antibody of TGBp1.The titer of this antibody is 1:1600.According to this study,we can preliminarily know TGBp1 can interact with host plant gene Nb Spd coding protein,and this interaction maybe is related to the virus accumulation and the resistance to virus of the host plant,it laid the foundation of theory for the mechanism of action of TGBp1 in infection.