Format: ORAL

Liming Cai1,2

1 Department of Integrative Biology, The University of Texas at Austin 2 Department of Biology, The University of Florida

A plants life is a constant battle for light and water. This autotrophic lifestyle has not only defined Viridiplantae but also profoundly shaped their body plan, physiology, reproduction, and genome. Yet in more than 4000 parasitic species, shifts to heterotrophy have fundamentally altered the selective regime for plants and left major evolutionary footprints. Features that are otherwise rare at the molecular level and beyond have evolved repetitively, including reduced vegetative bodies, shrunk gene repertoire, and an abundance of alien genes. Drawing from my previous work in parasitic plants, I recently proposed a conceptual model to attribute these convergent and predictable evolutionary trajectories to the cascading effects brought about by the loss of photosynthesis. Using Orobanchaceae as a model system, I will demonstrate at both molecular and phenotypic levels how repeated losses of photosynthesis in this family have led to convergent evolution in the genome and vegetative architecture. This family contains c.a. 2,300 species spanning the entire spectrum of parasitism from free-living species to non-photosynthetic holoparasites. In particular, I will focus on the understudied mitochondrial genome and present the first comparative study of leaf architecture in this family. I will also talk about future plans to use this family as a model to study species interaction from analytical chemistry, community ecology, macroevolution, and historical biogeography perspectives.