On the significance of mechanosensing for seed development and maturation
Final Report Abstract
ln many Brassicaceae species, the embryo's ultimate size is constrained by the volume of the embryosac. We thus hypothesized that the embryo needs to be able to sense how much space remains available for its expansion and to adjust its growth and metabolism accordingly. The significance of this project is two-fold: (1) we verified that a physical restriction to embryo growth induced a metabolic shift which redirected development away from expansion growth and into maturation, and (2) we identified molecular and biochemical factors, underlying the stimulation of embryo maturation via mechanical stimuli. This study provided evidence for a novel key element of embryo maturation: ones the state of competence is defined, the onset of a physical restriction to the embryo's growth boosts the cellular maturation programme. We identified multiple metabolic and regulatory genes as well as biochemical markers. The embryonic growth response involves signalling via some known transcriptional master regulators (ABA-related), redox and cell cycle regulators. At the biochemical level, we observed how the biosynthetic machinery is boosted in its activity to generate storage oils and proteins. The data also demonstrate how the glycolytic pathway flux is accelerated, thereby providing the necessary precursors for oils/proteins. We further elucidated that a subset of mechanosensitive genes shows a characteristic expression response. While this does not necessarily mean that they indeed are involved in regulating the embryonic growth response, it provides some candidates to work with in future studies in order to analyse in detail their contribution to the embryo's capacity to perform mechanosensing.
Publications
- (2021). The metabolic environment of the developing embryo: a multidisciplinary approach on oilseed rapeseed. Journal of Plant Physiology
Rolletschek H, Mayer S, Boughton B, Wagner S, Ortleb S, Kiel C, Roessner U, Borisjuk L
(See online at https://doi.org/10.1016/j.jplph.2021.153505) - (2021). The process of seed maturation is influenced by mechanical constrains. New Phytologist 229: 19–23
Rolletschek H, Muszynska A, Borisjuk L
(See online at https://doi.org/10.1111/nph.16815)
