The genome sequence of the Phalaenopsis equestris orchid, an economically-important ornamental plant, is reported in Nature Genetics.
The orchid is a member of one of the largest plant families, which has a variety of specialized reproductive and ecological adaptations. For example, it uses crassulacean acid metabolism (CAM), an alternative photosynthetic pathway to that of most plants.
Zhong-Jian Liu and colleagues sequenced the genome of the orchid Phalaenopsis equestris, the first CAM plant to have its genome sequenced. They identify MADS-box genes, which play important roles in flower development, and find that specific MADS-box gene families have expanded and diversified in the orchid. These findings suggesting that these genes may contribute to the highly specialized shape of orchid flowers. They also find evidence of ancient large-scale duplication events in the orchid genome, which the authors suggest may have been involved in the evolution of CAM.