Wheat, oats, rice, and other cereal grains are key pillars of human societies worldwide. Along with other members of the grass family, these plants provide the majority of the calories humans eat, either directly as grains or indirectly as meat and milk produced by grazing animals. Unfortunately, these important grasses are plagued by several families of plant viruses, including the barley and cereal yellow dwarf viruses, which damage cereal grain production worldwide. These viruses also harm wild grasses and can advance the spread of invasive species in nature. How have influential viruses like these emerged and what factors have contributed to their spread and diversification? To find clues about virus history, the project team will recover and analyze genetic sequences of old viruses preserved within historical collections of dried plants around the world. Phylogenetic analysis of the viruses will reveal how these viruses have spread over time and permit estimates of dates of key events in their history. The research will also provide information on the influence of humans on the spread of plant viruses.
Human development of agriculture and global trade are two factors that have likely influenced the emergence and spread of potent viruses. This research will provide missing information about virus dynamics in the past and produce new insight into the ways by which human activities influence the development of virus threats. The project's broader impact will include training of educators and students from underrepresented groups, contributions to microbial ecology outreach efforts through a science museum, and the addition of information about virus relationships to curated plant collections.
