Rice black-streaked dwarf virus P10 acts as either a synergistic or antagonistic determinant during superinfection with related or unrelated virus.

Hehong Zhang,Yuqing He,Fei Yan,Xiaoxiang Tan,Stuart Macfarlane,Junmin Li,Jing Li,Lulu Li,Rong Wang,Jianping Chen,Zongtao Sun,Kaili Xie,Gaojie Hong,Michael Taliansky

doi:10.1111/mpp.12782

Abstract

Summary Rice black‐streaked dwarf virus (RBSDV), a member of the genus Fijivirus, is a devastating pathogen of crop plants. RBSDV S10 encodes a capsid protein (P10) that is an important component of the double‐layered particle. However, little information is available on the roles of RBSDV P10 in viral infection or in interactions with other viruses. Here, we demonstrate that the expression of P10 in plants alleviates the symptoms of both RBSDV and the closely related Southern rice black‐streaked dwarf virus (SRBSDV), and reduces the disease incidence, but renders the plants more susceptible to the unrelated Rice stripe virus (RSV). Further experiments suggest that P10‐mediated resistance to RBSDV and SRBSDV operates at the protein level, rather than the RNA level, and is not a result of post‐transcriptional gene silencing. Transcriptomic data reveal that the expression of P10 in plants significantly suppresses the expression of rice defence‐related genes, which may play important roles in resistance to RSV infection. After infection with RBSDV, plants are more resistant to subsequent challenge by SRBSDV, but more susceptible to RSV. Overall, these results indicate that P10 acts as an important effector in virus interactions.

Highlights

Rice black-streaked dwarf virus (RBSDV), belonging to the genus Fijivirus in the family Reoviridae, is transmitted to rice, maize, barley and wheat by the small brown planthopper (Laodelphax striatellus) in a persistent, propagative manner (Wei and Li, 2016)
Our study looks at co-infections of rice with RBSDV and either a related reovirus, Southern rice blackstreaked dwarf virus (SRBSDV), or the unrelated Rice stripe virus (Phenuiviridae, Tenuivirus, RSV)
Our previous research has shown that RBSDV P10 is a membrane protein localized to the endoplasmic reticulum (ER) (Sun Z et al, 2013a)

Summary

Introduction

Rice black-streaked dwarf virus (RBSDV), belonging to the genus Fijivirus in the family Reoviridae, is transmitted to rice, maize, barley and wheat by the small brown planthopper (Laodelphax striatellus) in a persistent, propagative manner (Wei and Li, 2016). Most segments encode one protein, S5, S7 and S9 each have two open reading frames (Zhang et al, 2001). Segments S1, S2 and S3 encode an RNA-dependent RNA polymerase (P1), a core protein (P2) and a capping enzyme (P3), respectively. The P5-1, P6 and P9-1 proteins together constitute the viroplasm (Akita et al, 2012; Sun L et al, 2013; Wang et al, 2011), which is the site of viral replication and assembly. P7-1 is a protein that forms tubules at the plasmodesmata of plant cells (Isogai et al, 1998; Sun Z et al, 2013b). P8 and P10 are a core capsid protein and an outer capsid protein, respectively (Liu et al, 2007a, b; Sun Z et al, 2013a)

Results

Discussion

Conclusion