Much of what is known about the evolutionary fate of genes following genome doubling (polyploidy) is based on several crops that are thousands of years old and synthetic polyploids that are only several generations old. This project will investigate the very surprising finding that homeologous genes are lost rapidly after polyploidization, rather than being silenced or other regulatory changes. They want to know if there are general rules about which genes or larger pieces of genomes are preferentially lost. This is important because previous findings were from synthetic polyploids and recent natural polyploids (<100 years). The plant genus Tragopogon (goatsbeard, in the sunflower family) provides a unique opportunity to investigate changes that occur following polyploidy in nature across a range of ages. Tragopogon contains diploids, natural polyploids that are only 60-80 years old, synthetic polyploids, and older Eurasian polyploids. This study will investigate an older (0.8 -2.8 million years ago, mya) natural polyploid for comparison with the recently formed polyploids; it also extends to an ancient polyploidy event (>30 mya) early in the history of the sunflower family.
Genome doubling (polyploidy) has generated much of the diversity of life. All vertebrates and flowering plants experienced at least one episode of ancient polyploidy, and many crops are polyploids. Hence, elucidating the consequences of polyploidy will enhance our understanding of the diversification of life and provide fundamental knowledge about crop genomes. Results will provide important insights into the processes that generated much of life and most crops. In addition, the project will train undergraduate and graduate students, and a post-doctoral scholar, as well as including outreach activities to the general public.
