Circular dichroism studies of CMV-D and CMV-S: two strains of cucumber mosaic cucumovirus with a different biological behaviour

Summary Cucumber mosaic cucumovirus is a plant virus in which a typical satellite RNA system is present, displaying a dualistic biological behaviour. In fact, it has been shown that satRNA is able either to aggravate or attenuate the viral disease symptomatology with a modulating capability going from death of the host plant to a surprising absence of symptoms. D-satRNA and S-satRNA have been considered the prototype necrogenic and non necrogenic satRNAs respectively. On the basis of circular dichroism spectroscopy, it is suggested that the different biological behaviours can be explained by taking into account the different capabilities exerted by S- and D-satRNAs in inducing structuring effects onto CMV-S and CMV-D genomic RNAs.