About this Research Topic
As the most abundant and ubiquitous biological entities in aquatic systems, and with an estimated 1023 infections occurring every second in oceans, viruses are major agents of microbial mortality; hence, they play key roles in energy flow and element cycling in aquatic ecosystems. Infection and lysis affects abundance, metabolism, diversity and community structure of phytoplankton, bacterioplankton and zooplankton, with consequent effects on primary production and biogeochemical cycling. However, not all viral infections are lytic, and through lysogeny or other carrier states viruses can facilitate horizontal gene transfer between hosts, and between hosts and viruses; thus, resulting in the evolution of both hosts and viruses. Therefore, viruses are biologically, ecologically and biogeochemically important components in aquatic environments.
Despite their significance to aquatic ecosystems, our understanding of the ecological roles of viruses is relatively limited. In part, this is the result of a number of challenges. First, is the scarcity of representative host-virus systems with which to interrogate ecological interactions. The clearest evidence of the scale of the problem is that, by far, most of the sequences in aquatic viral metagenomic data sets have no significant similarity to genomic sequences from viral isolates. In fact, most metagenomic data still cannot be associated with a genomic home, or assigned a putative function. Second, is the lack of estimates of viral mediated mortality in many aquatic environments, which, in turn, means that inferring the contribution of viral lysis to nutrient cycling and community remains enigmatic. Third, little is known about spatial variability in viral communities and their ecological roles across aquatic environments, spanning lakes, rivers, estuaries, sediments, and vast regions of the oceans from the surface to the hadal depths. Fourth, there is a dearth of information on the composition and impact of viruses infecting eukaryotes from protists to fish across aquatic ecosystems.
This Research Topic will serve as a forum to gather the latest information on the ecology, impact and diversity of viruses across marine and freshwater environments. We welcome original research papers, reviews, perspectives and opinion papers exploring these topics from microbial, ecological, oceanographic and molecular perspectives.
Keywords: Viruses, Aquatic, Diversity, Ecology
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