HOW SIMILAR ARE PLANT AND INSECT VIRUSES? STRAWBERRY LATENT VIRUS: A STUDY CASE
A major outbreak of virus-induced strawberry decline in western North America from 2001 onwards, led us to investigate whether the graft-transmissible agents reported in the crop are also involved in this recently observed symptomatology. Strawberries infected with virus-like agents maintained at the National Clonal Germplasm Repository in Corvallis, OR were studied for the presence of viruses. One of those agents was discovered in the 1980s, in the course of identification of the causal agent of strawberry mild yellow edge disease. Martin and Converse (1985) identified and purified an icosahedral virus from strawberry mild yellow edge diseased plants. Later, it was discovered that the virus was also present in strawberry seedlings, derived from apparently healthy plants. This unknown virus was not studied further and its importance remained unknown, particularly when found in mixed infections with other viruses. Sequence data were obtained from dsRNA extracted from a plant of the original study. The data indicated that the virus, currently designated as Strawberry latent virus (StLV), is most closely related to the insect-infecting viruses of the genus Cripavirus. This may have implications in our understanding of the evolution of picorna-like viruses. Although there are some plant viruses that have distant relationships with insect-infecting viruses, StLV is linked more closely with members of the Cripavirus genus than any genera of plant viruses. The completion of the genome may reveal the presence of a movement protein or movement mode and transmission similar to that of cryptic viruses. Future plans include the study of the potential synergism of StLV with other major strawberry viruses and its role in the aphid transmissibility of Strawberry mild yellow edge virus.
Tzanetakis, I.E. and Martin, R.R. (2008). HOW SIMILAR ARE PLANT AND INSECT VIRUSES? STRAWBERRY LATENT VIRUS: A STUDY CASE. Acta Hortic. 780, 17-20
Fragaria, Dicistroviridae, Cripavirus, strawberry mild yellow edge, RT-PCR, detection