Skip to main content
padlock icon - secure page this page is secure

Free Content Functional analysis of Arabidopsis NCED6 and NCED9 genes indicates that ABA synthesized in the endosperm is involved in the induction of seed dormancy

Download Article:

You have access to the full text article on a website external to Ingenta Connect.

Please click here to view this article on Wiley Online Library.

You may be required to register and activate access on Wiley Online Library before you can obtain the full text. If you have any queries please visit Wiley Online Library


The cleavage of 9-cis-epoxycarotenoids to xanthoxin, catalyzed by 9-cis-epoxycarotenoid dioxygenases, is considered to be the key regulatory step of abscisic acid (ABA) biosynthesis. In Arabidopsis, genes for these enzymes form a multigene family with nine members, only five of which are thought to be involved in ABA production. In contrast to the prominent function of AtNCED3 in stress responses, the physiological and developmental role of the other 9 -cis-epoxycarotenoid dioxygenases (NCEDs) remain unknown. Our functional and expression analyses have revealed that AtNCED6 and AtNCED9 are required for ABA biosynthesis during seed development. Reverse genetic analysis showed that ABA levels were reduced in Atnced6 and Atnced9 mutant seeds. In addition, transgenic plants overexpressing the AtNCED6 gene overproduced ABA. In accordance with mutant phenotypes, both AtNCED6 and AtNCED9 exhibited seed-specific expression. Detailed cytological studies were carried out, either by using transcriptional fusions of the promoter with GUS and GFP reporter genes, or by in situ hybridization. Expression of AtNCED6 was observed exclusively in the endosperm during seed development, that of AtNCED9 in both embryo and endosperm at mid-development. In addition to reduced ABA levels, Atnced6 and Atnced9 mutant seeds were also resistant to paclobutrazol, a gibberellin biosynthesis inhibitor. Although seeds of single mutants were still dormant, reduced dormancy was observed in the Atnced6 Atnced9 double-mutant seeds. These demonstrate that ABA synthesized in both the endosperm and the embryo participates in the hormonal balance that controls seed dormancy and germination.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: abscisic acid; carotenoid; germination; mutant; paclobutrazol; seed dormancy

Document Type: Research Article

Affiliations: 1: Laboratoire de Biologie des Semences, UMR 204 INRA – INAPG, Institut Jean-Pierre Bourgin, 78026 Versailles Cedex, France 2: Laboratoire de Physiologie Cellulaire et Moléculaire des Plantes, FRE 2846 CNRS-Université Pierre et Marie Curie, Le Raphaël, 3 rue Galilée, 94200 Ivry-sur-Seine, France 3: Dormancy and Adaptation Research Team, Plant Science Center, RIKEN, Yokohama, 230-0045, Japan

Publication date: February 1, 2006

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more