Hybrid Speciation, Transposable Elements, and Genome Evolution in Wild Sunflowers

Kansas State University, Manhattan KS

Investigators

Abstract

Transposable elements are DNA sequences capable of mobilizing or proliferating in the genomes of their host. The natural conditions under which transposable elements become active and proliferate, and the consequences of proliferation events on host species evolution, are poorly understood. This research will investigate the genomic and environmental conditions that likely facilitated massive and independent proliferation events of gypsy-like long terminal repeat (LTR) retrotransposons in three diploid hybrid sunflower species adapted to extreme environments. The evolutionary history of the three hybrid sunflower species is especially relevant because both hybridization and environmental stress have been implicated as drivers of retrotransposon activation. Mobilization and proliferation activity of retrotransposons (as well as genomic modifications that can facilitate such events) will be investigated and characterized both in naturally occurring sunflower hybrids as well as in hybrid individuals synthesized and subjected to stress in the greenhouse. This project will greatly increase our understanding of the role of transposable elements in organismic evolution. Students involved in this project will be recruited through the KSU Developing Scholars Program. This program pairs KSU undergraduates from under-represented groups with faculty mentors to provide students with early opportunities for research endeavors. Other students will come through the KSU Summer Research Opportunities Program (SUROP) which also targets students from under-represented groups. The PI will participate in outreach through the NSF-funded GROW (Girls Researching Our World) Summer Workshop. This is a three-day summer science workshop for middle school age girls held on the KSU campus and at the nearby Konza Prairie Biological Station. Sunflowers play a prominent role in the natural history of the Flint Hills tall grass prairie in eastern Kansas. Outreach efforts will be directed towards the design and deliver a short workshop explaining basic aspects of sunflower natural history,domestication, and the use of these plants by Native American Peoples. This workshop will be delivered each summer for the duration of the proposed research.