Which plant was the first to have its genome completely sequenced?

Arabidopsis thaliana was the first plant to have its genome completely sequenced.

The sequencing project was published in 2000 and established a reference genome for a small flowering plant often called thale cress or mouse-ear cress. Arabidopsis is widely used in laboratories because it has a short life cycle, produces many seeds, occupies little space, and has a relatively small genome compared with many crop plants.

Its value is scientific rather than agricultural. Researchers use it to study flowering time, plant hormones, disease resistance, root development, and responses to light and stress. Discoveries in Arabidopsis can guide crop research, although results cannot always be transferred directly to every crop. The plant belongs to the mustard family, Brassicaceae, which also includes cabbage, broccoli, and radish.