Submitted to: Trends in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 19, 1996
Publication Date: N/A
Interpretive Summary: The manuscript is a comprehensive review of recent progress made in understanding the molecular mechanisms that regulate the transmission of plant viruses by their fungal or invertebrate vectors. The review attempts to identify common features and mechanisms used by diverse groups of viruses to be transmitted by their various vectors. Several new concepts and paradigms are proposed. For example, the mechanism of transmission can be divided into two broad categories; virus is either specifically and reversibly bound to external structures of the vector or virus is actively taken up across vector cell membranes and carried internally. This concept spans all vector taxa and unlike previous categorical descriptions of plant virus transmission is not limited to insect vectors. The most important (and likely to be controversial) paradigms put forth is that transmission of plant viruses is likely to involve a change in virus structure or in the econformation of virus proteins. These changes would occur due to exposure of the virus to unique environments encountered by the virus during its association with the vector. There is no direct experimental evidence to confirm many of the hypotheses proposed; however, all are indirectly supported by experimental results. Previous reviews have concentrated on mechanisms of virus transmission by insect vectors; this review attempts to encompass nematode and fungal vectors in addition to insect vectors. The review is the first to describe and detail the many common features (and potential mechanisms) that exist between viruses transmitted by very different vectors.
Technical Abstract: Plant viruses are transmitted by vectors either by reversibly binding to vector mouthparts or by being internalized by the vector and later secreted. Internalization requires virus proteins to mediate the uptake and transport of virus across vector cell membranes. Viral proteins are also involved in mediating the binding of plant viruses to vector mouthparts. Both types of transmission mechanisms are likely to involve conformational changes in the virus or virus proteins during their association with the vector.