Coleorhiza-enforced seed dormancy: a novel mechanism to control germination in grasses

0540629 - ÚEB 2021 RIV GB eng J - Článek v odborném periodiku
Holloway, T. - Steinbrecher, T. - Pérez, M. - Seville, A. - Stock, D. - Nakabayashi, K. - Leubner-Metzger, Gerhard
Coleorhiza-enforced seed dormancy: a novel mechanism to control germination in grasses.
New Phytologist. Roč. 229, č. 4 (2021), s. 2179-2191. ISSN 0028-646X. E-ISSN 1469-8137
Institucionální podpora: RVO:61389030
Klíčová slova: Avena fatua (common wild oat) * cell wall remodelling enzymes * grass seed dormancy * plant tissue interactions * seed tissue biomechanics * weed management
Obor OECD: Plant sciences, botany
Impakt faktor: 10.323, rok: 2021
Způsob publikování: Open access
http://doi.org/10.1111/nph.16948

How the biophysical properties of overlaying tissues control growth, such as the embryonic root (radicle) during seed germination, is a fundamental question. In eudicot seeds the endosperm surrounding the radicle confers coat dormancy and controls germination responses through modulation of its cell wall mechanical properties. Far less is known for grass caryopses that differ in tissue morphology. Here we report that the coleorhiza, a sheath-like organ that surrounds the radicle in grass embryos, performs the same role in the grass weed Avena fatua (common wild oat). We combined innovative biomechanical techniques, tissue ablation, microscopy, tissue-specific gene and enzyme activity expression with the analysis of hormones and oligosaccharides. The combined experimental work demonstrates that in grass caryopses the coleorhiza indeed controls germination for which we provide direct biomechanical evidence. We show that the coleorhiza becomes reinforced during dormancy maintenance and weakened during germination. Xyloglucan endotransglycosylases/hydrolases may have a role in coleorhiza reinforcement through cell wall remodelling to confer coat dormancy. The control of germination by coleorhiza-enforced dormancy in grasses is an example of the convergent evolution of mechanical restraint by overlaying tissues.
Trvalý link: http://hdl.handle.net/11104/0318249