From 2005 to 2009, the lab led an effort in Oklahoma to discover what viruses were associated with plants growing in the non-cultivated area represented by The Nature Conservancy's Tallgrass Prarie Preserve. The Plant Virus Biodiversity and Ecology team (supported by NSF-EPSCoR) found evidence of viruses in about 40% of plant samples, most of which did not show obvious signs of virus infection. The viruses, with very few exceptions, were not previously known viruses, but viruses related to known ones. There was variation between years in the incidence of infection that may correlate with dramatic weather differences between years. Hypotheses about determinants of virus distribution in this site have been generated.
For the past two years Melcher has been co-cordinator of the Plant Virus Ecology Network (an NSF-funded Research Coordination Network) that has brought together virologists, ecologists and entomologists to share information and thoughts about the complexities of virus distribution. At the most recent workshop, the main themes were: the influence of plant-associated viruses in shaping our world; human influences on virus distribution and evolution; and complexity and the networks of interactions occurring in plant virus ecology.
As a consequence of PVEN a team, headed by this laboratory, has assembled to apply to NSF for a Science and Technology Center for study of viruses in ecology. The full proposal is currently being evaluated. An important component of the Center is the investigation of the effects of climate change on virus ecology.
For two diverse virus taxa (tobamoviruses and mastreviruses) the lab has put forth the hypothesis that these viruses have codiverged with their hosts. Others believe, based on phylogenetic analysis, that viruses evolve much more rapidly. Reconciliation of the two point of view is in progress and centers on the quasispecies nature of plant virus populations and will investigate how they respond to growth and weather conditions.
The lab is associated with the National Institute for Microbial Forensics and Food and Agricultural Biosecurity. In this context, the interest is being able to predict the likelihood that a disease outbreak in a crop field is a natural event. This ability will depend on a thorough understanding of the effect of climate and weather on disease development.
E-mail enquiries to U. MelcherLast Updated: 10 August, 2004