Plant reoviruses hijack autophagy in insect vectors

Nearly 70% of plant virus species are transmitted by specific insect vectors, and this vector transmission is key for disease outbreaks.Understanding the mechanism by which the insects transmit the specific virus is critical for predicting and controlling the viral disease.Autophagy in insect vectors is activated through various pathways depending on the insect–virus combination after the insect acquires the plant reovirus.Plant reoviruses not only escape degradation by blocking fusion of autophagosomes and lysosomes, but also use unfused autophagosomes to assemble new virions or cross multiple membrane barriers in the insect.Entry of a plant reovirus into the insect vector can activate mitophagy to degrade damaged mitochondria to avoid mitochondria-dependent apoptosis, providing an optimal intracellular environment for persistent virus survival. Plant reoviruses, transmitted only by insect vectors, seriously threaten global cereal production. Understanding how insect vectors efficiently transmit the viruses is key to controlling the viral diseases. Autophagy commonly plays important roles in plant host defense against virus infection, but recent studies have shown that plant reoviruses can hijack the autophagy pathway in insect cells to enable their persistence in the insect and continued transmission to plants. Here, we summarize and discuss new insights on viral activation, evasion, regulation, and manipulation of autophagy within the insect vectors and the role of autophagy in virus survival in insect vectors. Deeper knowledge of the functions of autophagy in vectors may lead to novel strategies for blocking transmission of insect-borne plant viruses. Plant reoviruses, transmitted only by insect vectors, seriously threaten global cereal production. Understanding how insect vectors efficiently transmit the viruses is key to controlling the viral diseases. Autophagy commonly plays important roles in plant host defense against virus infection, but recent studies have shown that plant reoviruses can hijack the autophagy pathway in insect cells to enable their persistence in the insect and continued transmission to plants. Here, we summarize and discuss new insights on viral activation, evasion, regulation, and manipulation of autophagy within the insect vectors and the role of autophagy in virus survival in insect vectors. Deeper knowledge of the functions of autophagy in vectors may lead to novel strategies for blocking transmission of insect-borne plant viruses.