The mRNA surveillance factor Pelo restricts rice virus propagation in insect vectors and host plants

Abstract Many devastating plant viruses are transmitted by insect vectors among plant hosts in a persistent-propagative manner. Pelota (Pelo) is an evolutionarily conserved protein involved in the mRNA surveillance system. In this study, it was found that the accumulation of Pelo proteins are slightly decreased during the propagation of the fijivirus southern rice black-streaked dwarf virus (SRBSDV) in rice and transmission vector planthopper (Sogatella furcifera). The tubular protein P7-1 encoded by SRBSDV interacted with Pelo of rice or planthopper vector. Overexpression or knockdown of Pelo expression inhibits the formation of P7-1 tubules in insect cells, further exerting antiviral activity. Furthermore, overexpression or knockout of Pelo expression in transgenic rice plants also inhibits the effective propagation of SRBSDV as well as two other rice viruses of different families. The slight reduction of Pelo accumulation during SRBSDV propagation in rice and insect vectors would avoid Pelo-mediated excessive inhibition of P7-1 tubule formation, ensuring effective virus propagation. Our findings provide insights into how the up- or down-regulated expression of Pelo in rice hosts and insect vectors elevate their resistance to rice viruses.