XVI International Botanical Congess

Chloroplasts of all photosynthetic eukaryotes have two families of membrane-intrinsic light-harvesting antennas: plastid-encoded Core Antennas binding only Chl a, and nuclear-encoded LHC Superfamily(Chl a/b, Chl a/c)antennas. Both families have cyanobacteria relatives (Pcbs, Hlips): their 3D structures can be modeled on related proteins of known structure. Molecular phylogenetics supports convergent evolution of Chl a/b antennas in plants and prochlorophytes, and suggests that the evolution of Chl and carotenoid synthesis pathways was independent of the evolution of the pigment-binding proteins. An in vitro system is being used to study the import of Chl a/c proteins across the four plastid membranes of the chromist Heterosigma. The genomics approach yielded the first dinoflagellate plastid genes, which are quite divergent and located on single-gene minicircles.