The Plant Cell 21: 3803-3822 (2009)

Ethylene interacts with abscisic acid to regulate endosperm rupture during germination: a comparative approach using Lepidium sativum and Arabidopsis thaliana  [W][OA]

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
University of Freiburg, Faculty of Biology, Institute for Biology II, Botany / Plant Physiology, D-79104 Freiburg, Germany, Web: 'The Seed Biology Place' (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

Fig. 2 Linkies et al. (2009)

Figure 2. Endosperm cap hole formation of Lepidium sativum is a developmentally and hormonally regulated process.

(A) to (D) Endosperm cap hole formation was investigated by dissecting micropylar endosperm caps ([A]; isolated caps) from L. sativum FR1 seeds imbibed for 18 h in CON medium.

(B) and (C) Subsequent incubation of isolated caps (radicle removed) for several days on CON medium (B) or on medium with 1 mM ACC resulted in endosperm cap hole formation (arrow), which was inhibited when the isolated caps were incubated in the presence of the ethylene action inhibitor NBD ([C]; 100 mL/L applied via the gas phase).

(D) Prolonged incubation of caps with holes on CON medium leads in many cases to abscission of the cap tip (arrow).

(E) and (F) Percentage of isolated caps that formed holes by 3 and 12 d, respectively. ACC promoted cap hole formation and completely reverted the inhibiting effects of NBD and 3 mM ABA when added in combination to the incubation medium of the isolated caps. Mean values ± SE from two independent experiments with five and 12 isolated caps, respectively, are presented. All incubation conditions were continuous light at 18°C. Similar results were obtained for L. sativum FR14.

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.
Article in PDF format (1.8 MB)
Supplemental  data file (1.8 MB)
Abstract of Plant Cell 2009 
Fig. 1     
Fig. 6
Fig. S1
Fig. 2     
Fig. 7
Fig. S2
Fig. 3     
Fig. 8
Fig. S3
Fig. 4     
Fig. 9
Fig. S4
Fig. 5     
Fig. 10
Fig. S5
Hyperlink to
Datasets 1 to 9
          © American Society of Plant Biologists

The Seed Biology Place
Copyright © Gerhard Leubner 2000

Webdesign Gerhard Leubner 2000
Best viewed with browser version 4 and 800x600 pixel
This page was last updated on 30 January, 2010