Interaction Effect Between Coat Protein Of Bamboo Mosaic Virus And Host Protein Kinase SAPK3

Abscisic acid(ABA)plays a key role in plant disease defense,Bamboo mosaic virus(BaMV)is the main virus on bamboo,which seriously affects the commercial value and edible value of bamboo.It has been reported that the accumulation and movement of BaMV are affected by ABA.Sucrose non-fermenting 1-related protein kinase 2(SnRK2)is the signal transduction center of ABA and is a plant-specific stress response process.A class of protein kinases plays an important role in regulating the activity of substrate proteins and the expression of downstream resistance genes.Serine/threonine-protein kinase 3(SAPK3)is a subclass of Sucrose non-fermenting 1-related protein kinase2(SnRK2).Which is infectious to BaMV,the influence and interaction will provide new ideas for understanding the BaMV infection mechanism and plant antiviral pathways.In this paper,BaMV was used as the research object.The expression characteristics of NbSAPK3 gene after BaMV infection and BaMV CP were studied by Real-time fluorescent quantitative PCR,Bimolecular fluorescence and Complementation immunoprecipitation,GST-Pull down and BaMV pathogenicity analysis.The interactions and effects on BaMV replication provide a theoretical basis for further understanding the mechanism of BaMV infection on bamboo plants.The research results obtained are as follows:(1)Real-time qPCR test showed that the NbSAPK3 transcription level of healthy Nicotiana benthamiana was stable in different periods;BaMV-infected N.benthamiana induced the up-regulation of NbSAPK3 gene transcription level compared with healthy N.benthamiana.On day 8,day 16,and day 24,NbSAPK3 transcription levels were increased 4.2 times,8.5 times,and 7.1 times,respectively.(2)The experimental results of BaMV pathogenicity analysis showed that the transient overexpression of NbSAPK3 gene,compared with ordinary N.benthamiana,the expression level of the NbSAPK3 gene was increased 16 times,corresponding to the accumulation of BaMV increased by 6.9 times.The NbSAPK3 gene will inhibit the accumulation of BaMV by Virus-induced gene silencing(VIGS)technology,the accumulation of BaMV was reduced to 0.4 fold and 0.11 fold in the inoculated leaves and the system,respectively.The inhibitory effect was more obvious in the inoculated leaves than in the inoculated leaves,indicating that the NbSAPK3 gene enhanced the pathogenicity of BaMV to N.benthamiana.(3)BiFC,CO-IP and GST-Pull down tests show that NbSAPK3 protein will directly interact with BaMV coat protein in vivo and in vitro,BiFC test shows that NbSAPK3 will also interact with BaMV motor protein 1(TGBp1).The subcellular localization test found that NbSAPK3 and BaMV CP are localized in the nucleus and cytoplasm,and BaMV TGBp1 is localized in the cytoplasm;NbSAPK3 and BaMV CP subcellular co-localization also appears in the nucleus and cytoplasm,but very few parts of NbSAPK3 and BaMV TGBp1 will share Positioned together.Based on the above research results,the NbSAPK3 gene has a certain promoting effect on the accumulation of BaMV and further found that NbSAPK3 interacts with CP.It is preliminarily speculated that NbSAPK3 interacts with BaMV CP to promote virus infection,increase virus accumulation and weaken,The resistance of host plants to viruses.The research provides a theoretical basis for further elucidating BaMV’s infection mechanism and plant anti-virus research.