Scientists completed the first orchid whole genome sequencing

As one of the most diverse plant family, orchid now has its first genome sequenced and the result is published at Nature Genetics as a cover article.

This study is an accomplishment of the Orchid Genome Project, an international collaboration led by Lai-Qiang Huang and Zhong-Jian Liu at Tsinghua University and National Orchid Conservation Center in Shenzhen China.

The team carried out whole genome sequencing on Phalaenopsis equestris, which is an important parental species for breeding of commercial phalaenopsis strains. P. equestris is also the first plant with Crassulacean Acid Metabolism (CAM) for which the genome has been sequenced.

The assembled genome contains 29,431 predicted protein-coding genes. The average intron length is 2,922 base pairs, which is much longer than in any sequenced plant genomes. Further analysis indicate that transposable elements in introns are the major reason why orchid genes have so big introns.

Like in many plant genomes, they also found evidence for an orchid-specific paleopolyploidy event that preceded the radiation of most orchid clades. This is possibly an important clue to why orchid developed into one of the largest plant families on earth.

The complete genome sequence of P. equestris will provide an important resource to explore orchid diversity and evolution at the genome level. The genome sequence will also be a key resource for the development of new concepts and techniques in genetic engineering.