Format: ORAL

Pamela S. Soltis

Florida Museum of Natural History, University of Florida, Gainesville, USA

The genomes of green plants vary tremendously in size, transposable element content, and structural complexity, making sequencing, assembly, and annotation challenging. Although many published plant genomes are complete or nearly so at the gene sequence level, their assemblies remain fragmentary, precluding certain types of comparative analyses. However, recent advances in sequencing technology and analytical software are enabling chromosome-level assemblies even for large and complex genomes. Thus, high-quality reference genomes are being generated for many clades, providing key insight into specific genotype-to-phenotype relationships and facilitating comparative genomic analyses on an unprecedented scale. Large-scale community sequencing projects have been particularly effective at generating genomic anchors for diverse clades, and notable insights are emerging. Key among them is the consistent evidence for widespread whole-genome duplication, with even very small genomes bearing signatures of multiple duplication events. In other cases, expansions of gene families and the identification of gene clusters are being linked to production of key metabolites, defense compounds, and disease resistance. One of the most surprising discoveries is the frequency of ancient reticulation, based on extensive gene-tree conflict. How general are these results to date? Ongoing large-scale sequencing projects will continue to generate new genomes, but the number of plant species is immense, and many more such efforts are needed, particularly as the concept of the reference genome evolves from a high-quality assembly for a single individual to a pangenome that represents a species. Fortunately, the tools for sequencing, assembling, and annotating genomes are improving rapidly, and we can look forward to novel discoveries and the possibility of any plant species becoming a genomic model.