Viruses, the most abundant form of life on Earth, may be essential to the functioning of diverse ecosystems
The community of viruses is staggeringly vast. Occupying every conceivable biological niche, from searing undersea vents to frigid tundra, these enigmatic invaders, hovering between inert matter and life, circumnavigate the globe in the hundreds of trillions. They are the most abundant life forms on earth.
Viruses are justly feared as ingenious pathogens, causing diseases in everything they invade, including virtually all bacteria, fungi, plants and animals. Recent advances in the field of virology, however, suggest that viruses play a more significant and complex role than previously appreciated, and may be essential to the functioning of diverse ecosystems.
We now know that humans contain roughly 100,000 pieces of viral DNA elements, which make up around 8 percent of our genome. Speculation on the role of these ancient viral fragments ranges from protection against disease to increasing the risk of cancer or other serious illnesses, though researchers acknowledge they have barely scratched the surface of this enigma.
A new review article appearing in the journal Nature Reviews Microbiology highlights the evolution and ecology of plant viruses. Arvind Varsani, a researcher at ASU’s Biodesign Institute joins an international team to explore many details of viral dynamics. They describe the subtle interplay between three components of the viral infection process, the virus itself, the plant cell hosts infected by the virus and the vectors that act as go-betweens—an intricate system evolving over some 450 million years. All three elements are embedded within wider relations of the surrounding ecosystem.
Recent studies in the field of virology have shown that viruses are sometimes beneficial to the organisms they infect. “Prior to this people have always seen viruses as disease-causing entities,” Varsani says. “This breaks all the dogmas of how we study viruses. We have a section where we review mutualism and symbiosis and also how some of the symbiotic relationships are being uncoupled.” [Continue reading…]