Related Experiment Video
Updated: Feb 7, 2026

Immunofluorescent Labeling of Plant Virus and Insect Vector Proteins in Hemipteran Guts
Published on: May 14, 2021
Invasion of midgut epithelial cells by a persistently transmitted virus is mediated by sugar transporter 6 in its
Faliang Qin1, Wenwen Liu1, Nan Wu1
1State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Abstract:
Insect transmission is obligatory for persistently transmitted viruses because the vector insect is the only means of virus spread in nature. The insect midgut is the first major barrier limiting virus acquisition, but the mechanisms by which viruses are able to cross the cell membrane and then infect the midgut epithelial cells of the insect have not been elucidated completely. Here, we found that the outer capsid or nucleocapsid protein (NP) of three viruses can interact and colocalize with sugar transporter 6 that is highly expressed in the midgut of Laodelphax striatellus (LsST6). In contrast, LsST6 did not interact with the NP of rice grassy stunt virus, which cannot be transmitted by the same planthopper. LsST6 not only altered the cellular location of viral proteins and then colocalized with them in the cell membrane, but also mediated the entry of rice stripe virus (RSV) particles into Spodoptera frugiperda 9 (Sf9) cells that expressed the heterologous gene LsST6. We further showed that RSV particles initially bound to the cell membrane of midgut epithelial cells where it colocalized with LsST6, and then invaded the cytoplasm. When LsST6 expression was knocked down, viral titre, acquisition percentage and transmission efficiency of the treated insect decreased significantly, but virus replication was not affected. This work thus uncovered a strategy by which LsST6 mediates viral entry into midgut epithelial cells and leads to successful transmission by the insect vector.
Related Concept Videos
Phloem and Sugar Transport
Osmoregulation in Insects
Carrier-Mediated Transport
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
Secondary Active Transport
Short-distance Transport of Resources
Sexually Transmitted Infections

