A Novel Iflavirus Was Discovered in Green Rice Leafhopper and Its Proliferation Was Inhibited by Infection of Rice Dwarf Virus.

The green rice leafhopper, (Hemiptera: Cicadellidae), is a key insect vector transmitting rice dwarf virus (RDV) that causes rice dwarf disease. We discovered a novel iflavirus from the transcriptomes of and named it as Nephotettix cincticeps positive-stranded RNA virus-1 (NcPSRV-1). The viral genome consists of 10,524 nucleotides excluding the poly(A) tail and contains one predicted open reading frame encoding a polyprotein of 3,192 amino acids, flanked by 5' and 3' untranslated regions. NcPSRV-1 has a typical iflavirus genome arrangement and is clustered with the members of the family in the phylogenetic analysis. NcPSRV-1 was detected in all tested tissues and life stages of and could be transmitted horizontally and vertically. Moreover, NcPSRV-1 had high prevalence in the laboratory populations and was widely spread in field populations of . NcPSRV-1 could also infect the two-striped leafhopper, , at a 3.33% infection rate, but was absent in the zigzag leafhopper, , and rice variety TN1. The infection of RDV altered the viral load and infection rate of NcPSRV-1 in , for which it seems that RDV has an antagonistic effect on NcPSRV-1 infection in the host.