Molecular Mechanism Of Rice Ragged Stunt Virus (RRSV) Proliferation In Insect Vector,Brown Planthopper

Rice ragged stunt virus(RRSV),a member of rice Reoviruses belonging to the genus Oryzavirus in family Reoviridae,caused serious economic damage to rice production in South and East Asia.The rice plant infected with RRSV showed stunting,and the leaves were abnormal with serrated edges or twisted tips.RRSV was specifically transmitted by the brown planthopper(BPH,Nilaparvata lugens).The insect acquires RRSV through feeding on the infected rice plants,and the virus dispersesd or circulated within the insect vectors.The RRSV Pns10 was an important protein for assembly of the viroplasm,where the viral replication and proliferation take places.In this study,yeast two-hybrid system was used to identify the potential interaction between the RRSV Pns10 and host proteins.We firstly constructed a cDNA library of N.lugens,and screened the host library using a bait of Pns10.A total of 11 potential interacting proteins were found,which includ MD-2-related lipid-recognition protein(ML)?Sorting and assembly machinery component 50(SAM50),and Calpain-7-like protein.The interaction between the Pns10 and ML was further confirmed by GST pull-down assay.Knocking down the NlML expression by RNA interference resulted in prolonged evelopmental duration,which was significant different from that of the control.When infected with RRSV,the MAL-deficient BPHs showed increased viral replication rate than that of the control at the 4th and 6th day.The altered proliferation rate might be correlated with TOLL pathway and the host immune system cannot recognize the virus without the participation of NlML,resulting in increased viral proliferation.