The Plant Cell 21: 3803-3822 (2009) |
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Ethylene interacts with abscisic acid to regulate endosperm rupture during germination: a comparative approach using Lepidium sativum and Arabidopsis thaliana [W][OA] |
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Ada Linkies, Kerstin Müller, Karl Morris, Veronika Turecková, Meike Wenk, Cassandra S. C. Cadman, Françoise Corbineau, Miroslav Strnad, James R. Lynn, William E. Finch-Savage, Gerhard Leubner-Metzger |
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University of Freiburg, Faculty of Biology, Institute for Biology II, Botany / Plant Physiology, D-79104 Freiburg, Germany, Web: 'The Seed Biology Place' http://www.seedbiology.de (A.L., Ke.M., M.W., G.L.-M.) Warwick Horticulture Research International (HRI), Warwick University, Wellesbourne, Warwick CV35 9EF, United Kingdom (Ka.M., C.S.C.C., J.R.L., W.E.F.-S.) Palacky University and Institute of Experimental Botany Academy of Sciences of the Czech Republic, Laboratory of Growth Regulators, CZ-78371 Olomouc, Czech Republic (V.T., M.S.) Université Pierre et Marie Curie-Paris 6, Germination et Dormance des Semences, UR5, Site d'Ivry, F-75005 Paris, France (F.C.) Received July 23, 2009; Returned for revision October 12, 2009; Accepted November 17, 2009; Published December 18, 2009 www.plantcell.org/cgi/doi/10.1105/tpc.109.070201 |
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Figure 9. The effect of ACC, NBD, ABA, or their combinations on endosperm cap weakening and endosperm rupture of Lepidium sativum FR14. Endosperm cap weakening (columns) and rupture (percentages above columns) of seeds incubated without (CON) or with 1 mM ACC or 10 µM ABA added to the medium in continuous light at 24°C ([A] and [C]) or 14°C (B). Endosperm cap weakening was determined by measuring tissue resistance by the puncture force method at the times indicated. All the seeds selected for the puncture force measurements had completed testa rupture but still had intact endosperm caps; ACC, NBD, and ABA did not appreciably affect testa rupture. Mean values ±SE of 3 x 50 seeds for the endosperm rupture and at least 50 endosperm caps for the puncture force measurements are presented. Note that the puncture force values measured for the endosperm cap weakening of L. sativum FR14 were approximately twofold compared with L. sativum FR1 (Figure 1). These higher values are accession-specific absolute differences, but the relative decreases of the two accessions are similar. Synopsis: Tissue weakening of the endosperm is required to allow radicle protrusion during seed germination. Cross-species work including tissue-specific transcriptome analysis and biomechanical measurement of endosperm weakening provided a new mechanistic model that explains how ethylene promotes seed germination and counteracts the inhibition of endosperm cap weakening by abscisic acid. | ||||||||||
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