RNA viruses have a great potential for genetic variation, rapid evolution and adaptation. Characterization of the genetic variation of viral populations provides relevant information on the processes involved in virus evolution and epidemiology and it is crucial for designing reliable diagnostic tools and developing efficient and durable disease control strategies. Here we performed an updated ...

Chlorotic fleck, a strawberry disease caused by a graft and aphid transmissible agent, was identified more than 45 years ago in Louisiana. Since its discovery there has been no additional information on the agent that causes the disease. The mode of transmission implies that a virus is the causal agent of chlorotic fleck. We identified four closteroviruses in the single chlorotic fleck infected...

To understand ecological factors mediating the spread of insect-borne plant pathogens, vector species for these pathogens need to be identified. Grapevine leafroll disease is caused by a complex of phylogenetically related closteroviruses, some of which are transmitted by insect vectors; however, the specificities of these complex virus-vector interactions are poorly understood thus far. Throug...

Pineapple, Ananas comosus (L.) Merr., is a perennial, xerophytic monocot in the Bromeliaceae family (13). Planting materials used for commercial production are typically the crown from the top of the fruits (19). The planted crowns, referred to as the plant crop, will each produce a single pineapple fruit 18 to 20 months after planting (19). Following plant crop harvest, a ratoon crop develops ...

Lettuce infectious yellows virus (LIYV) is the type member of the genus Crinivirus in the family Closteroviridae. Like many other positive-strand RNA viruses, LIYV infections induce a number of cytopathic changes in plant cells, of which the two most characteristic are: Beet yellows virus-type inclusion bodies composed of vesicles derived from cytoplasmic membranes; and conical plasmalemma depo...

The mitochondrial genome of grape (Vitis vinifera), the largest organelle genome sequenced so far, is presented. The genome is 773,279 nt long and has the highest coding capacity among known angiosperm mitochondrial DNAs (mtDNAs). The proportion of promiscuous DNA of plastid origin in the genome is also the largest ever reported for an angiosperm mtDNA, both in absolute and relative terms. In a...

Members of the Closteroviridae and Potyviridae families of the plant positive-strand RNA viruses encode one or two papain-like leader proteinases. In addition to a C-terminal proteolytic domain, each of these proteinases possesses a nonproteolytic N-terminal domain. We compared functions of the several leader proteinases using a gene swapping approach. The leader proteinase (L-Pro) of Beet yell...