Dispersal biophysics and adaptive significance of dimorphic diaspores in the annual Aethionema arabicum (Brassicaceae)

0502991 - ÚEB 2019 RIV GB eng J - Journal Article
Arshad, W. - Sperber, K. - Steinbrecher, T. - Nichols, B. - Jansen, V.A.A. - Leubner-Metzger, Gerhard - Mummenhoff, K.
Dispersal biophysics and adaptive significance of dimorphic diaspores in the annual Aethionema arabicum (Brassicaceae).
New Phytologist. Roč. 221, č. 3 (2019), s. 1434-1446. ISSN 0028-646X. E-ISSN 1469-8137
Institutional support: RVO:61389030
Keywords : abscisic acid (ABA) * Aethionema arabicum * bet-hedging * dimorphic diaspores * dispersal by wind and water * environmental adaptations * fruit biomechanics * pericarp-imposed properties
OECD category: Plant sciences, botany
Impact factor: 8.512, year: 2019

Heteromorphic diaspores (fruits and seeds) are an adaptive bet-hedging strategy to cope with spatiotemporally variable environments, particularly fluctuations in favourable temperatures and unpredictable precipitation regimes in arid climates. We conducted comparative analyses of the biophysical and ecophysiological properties of the two distinct diaspores (mucilaginous seed (M + ) vs indehiscent (IND) fruit) in the dimorphic annual Aethionema arabicum (Brassicaceae), linking fruit biomechanics, dispersal aerodynamics, pericarp-imposed dormancy, diaspore abscisic acid (ABA) concentration, and phenotypic plasticity of dimorphic diaspore production to its natural habitat and climate. Two very contrasting dispersal mechanisms of the A. arabicum dimorphic diaspores were revealed. Dehiscence of large fruits leads to the release of M + seed diaspores, which adhere to substrata via seed coat mucilage, thereby preventing dispersal (antitelechory). IND fruit diaspores (containing nonmucilaginous seeds) disperse by wind or water currents, promoting dispersal (telechory) over a longer range. The pericarp properties confer enhanced dispersal ability and degree of dormancy on the IND fruit morph to support telechory, while the M + seed morph supports antitelechory. Combined with the phenotypic plasticity to produce more IND fruit diaspores in colder temperatures, this constitutes a bet-hedging survival strategy to magnify the prevalence in response to selection pressures acting over hilly terrain.
Permanent Link: http://hdl.handle.net/11104/0294825