Biology and Evolution of Beneficial and Detrimental Viruses of Animals, Plants, and Fungi

Virtually every type of organism may serve as a host for viruses. In some hosts, virus presence may be considered beneficial to humans; in other hosts, viruses are considered detrimental. Examples of viruses that are considered beneficial to humans include those that are used for biological control of organisms that themselves are considered detrimental to humans, such as plant pathogenic fungi. Viruses are extremely variable in terms of morphology, structure, and genome organization. However, viruses that attack hosts from different kingdoms may be related, deriving from the same phylogeny. This paper summarizes some of the properties of three related families of viruses that attack hosts in different kingdoms: the animal-infecting Picornaviridae, the plant-infecting Potyviridae, and the fungus-infecting Hypoviridae. Properties of these viruses that set them apart from each other and factors that may affect their evolution are discussed.