Abstract
Host-to-host transmission—a key step in plant virus infection cycles—is ensured predominantly by vectors, especially aphids and related insects. A deeper understanding of the mechanisms of virus acquisition, which is critical to vector-transmission, might help to design future virus control strategies, because any newly discovered molecular or cellular process is a potential target for hampering viral spread within host populations. With this aim in mind, an aphid membrane-feeding assay was developed where aphids transmitted two non-circulative viruses [cauliflower mosaic virus (CaMV) and turnip mosaic virus] from infected protoplasts. In this assay, virus acquisition occurs exclusively from living cells. Most interestingly, we also show that CaMV is less efficiently transmitted by aphids in the presence of oryzalin—a microtubule-depolymerising drug. The example presented here demonstrates that our technically simple “virus-acquisition phenotyping assay” (VAPA) provides a first opportunity to implement correlative studies relating the physiological state of infected plant cells to vector-transmission efficiency.
Highlights
Transmission is a critical step in the infection cycle of every virus, because it controls dispersal in space and time, directly influencing epidemiology
As a validation of this assay, we showed that disintegration of protoplasts totally abolished vector-transmission but not mechanical transmission of cauliflower mosaic virus (CaMV) and turnip mosaic virus (TuMV)
Further evidence for the biological relevance of the protoplast acquisition system comes from the observation that CaMV acquisition was significantly affected by depolymerisation of host cell microtubules with oryzalin
Summary
Transmission is a critical step in the infection cycle of every virus, because it controls dispersal in space and time, directly influencing epidemiology. Aphids play a dominant role as they transmit about one-third of all known plant viruses (reviewed in [1]). This is due partly to their non-destructive feeding behaviour. When alighting on a new plant, aphids first insert their stylets (the proboscis-like mouth parts) into epidermal and mesophyll cells in order to test plant palatability. These test punctures last only seconds and usually preserve plant cell integrity. Aphids can acquire viruses efficiently during one of these feeding steps, or even during both steps, depending on the viral species (e.g. [3])
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
