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

Cucumber mosaic cucumovirus is a plant virus in which a typical satellite R NA 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-satR NA have been considered the prototype necrogenic and non necrogenic satRNAs respectively. On the basis of circular dichroism spectroscopy, it is suggested that the d ifferent 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.