Southern rice black-streaked dwarf virus Alters Insect Vectors' Host Orientation Preferences to Enhance Spread and Increase Rice ragged stunt virus Co-Infection

Abstract

In recent years, Southern rice black-streaked dwarf virus (SRBSDV), a tentative species in the genus Fijivirus (family Reoviridae), has spread rapidly and caused serious rice losses in eastern and southeastern Asia. With this virus spread, Rice ragged stunt virus (RRSV, genus Oryzavirus, family Reoviridae) became more common in southern China, usually in co-infection with the former. SRBSDV and RRSV are transmitted by two different species of planthoppers, white-backed planthopper (WBPH, Sogatella furcifera) and brown planthopper (BPH, Nilaparvata lugens), respectively, in a persistent, circulative, propagative manner. In this study, using a Y-shape olfactometer-based device, we tested the host preference of three types of macropterous WBPH adults for healthy or SRBSDV-infected rice plants. The results showed that virus-free WBPHs significantly preferred infected rice plants to healthy plants, whereas both the viruliferous and nonviruliferous WBPHs preferred healthy plants to infected plants. In additional tests, we found that the BPHs significantly preferred healthy plants when they were virus free, whereas RRSV-carrying BPHs preferred SRBSDV-infected rice plants. From these findings, we propose that plant viruses may alter host selection preference of vectors to enhance their spread and that of insects vectoring another virus to result in co-infection with more than one virus.

Rice Reoviruses in Insect Vectors

“…For example, SRBSDV-infected plants are more attractive to nonviruliferous S. furcifera individuals but less so to the viruliferous ones, whereas healthy plants are more attractive to the viruliferous but less so to the nonviruliferous individuals (131). Furthermore, RRSV-carrying N. lugens individuals prefer SRBSDV-infected rice plants (62,104). Thus, rice reoviruses may alter the host's preference for vectors to enhance their transmission and for insects that vector another virus to result in coinfection with more than one virus (62,104).…”

“…Furthermore, RRSV-carrying N. lugens individuals prefer SRBSDV-infected rice plants (62,104). Thus, rice reoviruses may alter the host's preference for vectors to enhance their transmission and for insects that vector another virus to result in coinfection with more than one virus (62,104). Perhaps plant volatile organic emissions affect insects' preference for or attract them to virus-infected host plants, but this possibility has not been studied.…”

Plant Virus–Insect Vector Interactions: Current and Potential Future Research Directions

“…Luteovirid acquisition by aphids appears to alter host selection behavior to prefer uninfected plants while non-viruliferous aphids tend to prefer virus-infected plants, thereby promoting both virus acquisition and transmission [99,100]. Similar virus effects on host preferences of the vector were observed for reovirus-infected and virus-free planthoppers [101]. The nuclear inclusion a (NIa) protease protein of turnip mosaic potyvirus has been implicated in manipulating host plant physiology to attract aphid vectors and to promote their reproduction [102].…”

A simplified method for simultaneous detection of Rice stripe virus and Rice black-streaked dwarf virus in insect vector

“…It has been reported that host selection preference of insect vector may be altered by plant virus. For instance, viruliferous (Southern rice black-streaked dwarf virus) white-backed planthopper (WBPH) preferred healthy rice plants to infected plants, whereas virus-free WBPH preferred infected plants (Wang et al, 2014). The tripartite interactions of virus-vector-plant relationships are complex (Hogenhout et al, 2008).…”