Abstract
Rice stripe virus (RSV) transmitted by the small brown planthopper causes severe rice yield losses in Asian countries. Although viral nuclear entry promotes viral replication in host cells, whether this phenomenon occurs in vector cells remains unknown. Therefore, in this study, we systematically evaluated the presence and roles of RSV in the nuclei of vector insect cells. We observed that the nucleocapsid protein (NP) and viral genomic RNAs were partially transported into vector cell nuclei by utilizing the importin α nuclear transport system. When blocking NP nuclear localization, cytoplasmic RSV accumulation significantly increased. In the vector cell nuclei, NP bound the transcription factor YY1 and affected its positive regulation to FAIM. Subsequently, decreased FAIM expression triggered an antiviral caspase-dependent apoptotic reaction. Our results reveal that viral nuclear entry induces completely different immune effects in vector and host cells, providing new insights into the balance between viral load and the immunity pressure in vector insects.
Highlights
As a primary grain crop, rice feeds more than half of the world’s population (Sasaki and Burr, 2000)
We observed that the nucleocapsid protein (NP) and viral genomic RNAs were partially transported into vector cell nuclei by utilizing the importin α nuclear transport system
These results show that the ribonucleoprotein particles (RNPs) of Rice stripe virus (RSV) are able to enter the cell nuclei of planthoppers
Summary
As a primary grain crop, rice feeds more than half of the world’s population (Sasaki and Burr, 2000). The genome of RSV consists of four RNA segments. The other three segments are ambisense and each encodes two proteins, i.e., NS2 and NSvc encoded by RNA2, NS3 and nucleocapsid protein (NP) by RNA3, and SP and NSvc by RNA4 (Toriyama, 1986; Hamamatsu et al, 1993). RSV is a typical persistent-propagative phytovirus that is efficiently transmitted by the small brown planthopper Laodelphax striatellus. It replicates and assembles in the cytoplasm of both planthopper and rice cells, RSV performs differently when living in the two organisms, exhibiting different pathogenicities (Zhao et al, 2016a), replication and gene expression levels (Zhao et al, 2019), genomic 3′-termini (Zhao et al, 2018), and virusderived siRNAs (Yang et al, 2018)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
