The Draft Genome of Kalanchoë fedtschenkoi: A Model Plant Species for the Study of Crassulacean Acid Metabolism (CAM)

Cassulacean acid metabolism (CAM) is a plant photosynthetic adaptation providing high water-use efficiency for species inhabiting arid and semi-arid climates. We report a draft genome of a CAM species; the succulent, drought tolerant Kalanchoë fedtschenkoi, endemic to Madagascar. K. fedtschenkoi uses both CAM and the ancestral C3 photosynthetic mechanism under different environmental conditions and through analysing global gene expression we have  identified many up-regulated genes in the CAM pathway. Genome analysis revealed that genes recruited to CAM photosynthesis had arisen both by gene duplication/neofunctionalisation, and neofunctionalisation of pre-existing ancestral copies. Our data provide a deeper understanding of the CAM metabolic pathway and genomic information for a new model species, setting the foundation for future efforts to engineer enhanced photosynthetic mechanisms into major food and bioenergy crops.