Morphomechanical Innovation Drives Explosive Seed Dispersal

How mechanical and biological processes are coordinated across cells, tissues, and organs to produce complex traits is a key question in biology. Cardamine hirsuta, a relative of Arabidopsis thaliana, uses an explosive mechanism to disperse its seeds. We show that this trait evolved through morphomechanical innovations at different spatial scales. At the organ scale, tension within the fruit wall generates the elastic energy required for explosion. This tension is produced by differential contraction of fruit wall tissues through an active mechanism involving turgor pressure, cell geometry, and wall properties of the epidermis. Explosive release of this tension is controlled at the cellular scale by asymmetric lignin deposition within endocarp b cells-a striking pattern that is strictly associated with explosive pod shatter across the Brassicaceae plant family. By bridging these different scales, we present an integrated mechanism for explosive seed dispersal that links evolutionary novelty with complex trait innovation.

Built in Jerusalem's Wall /

Mode of access: Internet.

The arts connected with building: lectures on craftsmanship and design delivered at Carpenters hall, London wall, for the worshipful company of carpenters /

On title page: With 98 illustrations of old and modern work.

Impact behavior of thin-wall steel tube signposts and delineator post. Final report.

Texas State Department of Highway and Public Transportation, Transportation Planning Division, Austin

Oblique angle crash tests of loaded heavy trucks into an instrumented wall. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Villa Agrippa Posthumus, cubiculum nocturnum, north wall, center panel, Aedicula with a small landscape

Boscotrecase, Italy; fresco on black ground

Villa of Mysteries, interior, Room of Mysteries, west wall, Domina

Pompeii (deserted settlement), Italy

Tomb, excavated artifact, Rabbits, Birds, Bamboo and Flowers, center portion: birds and flowers; from the western interior wall of the outer (xiaozhang) coffin

Liaoning. Faku. Yemaotai; hanging scroll, ink and colors on silk

Villa of Publius Fannius Synistor, interior, Cubiculum (Bedroom) M, rear wall

Boscoreale, Italy; fresco

Villa of Publius Fannius Synistor, interior, Cubiculum (Bedroom) M, right wall, second panel

Boscoreale, Italy; fresco