C4A and infection: Amin et al. [40] have shown that expression of the AC4 (a homolog of the C4 proteins of monopartite begomoviruses) protein of Cabbage leaf curl virus (a bipartite begomovirus originating from the New World which is only distantly related to AEV) from a Potato virus X vector induced a very similar dimple structure on leaves of N. benthamiana. For AEV however, infection of N. benthamiana in the absence of the betasatellite did not induce symptoms, suggesting that in this case the unusual symptom is due betasatellite rather than the virus.