Trends in Plant Science

Trends in Plant Science

Volume 13, Issue 8, August 2008, Pages 444-450
Journal home page for Trends in Plant Science

Review
Arabidopsis ovule development and its evolutionary conservation

https://doi.org/10.1016/j.tplants.2008.04.011Get rights and content

Ovules have an important role during the life cycle of the plant, and they provide an excellent model for studying organogenesis in plants. As such, the molecular control of ovule development has been studied for many years. Recent studies in Arabidopsis have revealed important new data concerning ovule primordia formation, ovule identity determination, and patterning. Furthermore, interesting results about ovule development in other species, such as Petunia and rice, have been published recently. In this review, we discuss these recent findings in reference to ovule development in Arabidopsis. We compare available data with those of other species to investigate the evolutionary conservation of the regulatory pathways.

Section snippets

Molecular control of the determination of ovule identity

Ovules are complex structures that develop from the placenta and are the precursors of seeds. Three fundamental elements can be distinguished from the proximal–distal axis: the funiculus, which attaches the ovule to the placenta; the chalaza, which forms the integument(s); and the nucellus, which is covered by the integuments and in which the megaspore mother cell differentiates to form the embryo sac. Genes that determine the identity of the ovule have been identified and studied in detail in

The control of floral meristem determinacy in relation to placentation types

Various data in the literature support the hypothesis that the mode of placental development determines when floral meristem activity terminates 20, 21, 22, 23. In Petunia and rice, the floral meristem is maintained after carpel primordial development, because placenta and ovules arise directly from the inner part of the floral meristem (Figure 2de). By contrast, in Arabidopsis, both the placenta and the ovules differentiate from the inner ovary wall (Figure 2a–c).

Related to these differences

Upstream and downstream ovule identity genes

Several approaches have been used to identify target genes involved in floral organ identity complexes 30, 31, 32. However, until now, direct target genes of ovule identity factors have not been identified. One promising approach to identify these factors is the use of chromatin immunoprecipitation in combination with massive sequencing approaches, which enables genome-wide identification of target genes [33].

More information is available for upstream regulators of ovule identity genes in

Symmetry establishment during ovule development

Ovules are characterized by a proximal–distal (P–D) symmetry during early stages of development and by an adaxial–abaxial (Ad–Ab) polarity at the time of integument differentiation and elongation. A crucial developmental step is the correct switch from P–D symmetry to Ad–Ab polarity. In Arabidopsis, this switch is marked by initiation of the outer integument on the abaxial side and, from a molecular point of view, by the expression of INO at the abaxial side of the chalaza region, where the

Concluding remarks and future perspectives

We think that an exciting scenario is emerging because, at least for the model species Arabidopsis, a detailed picture of the molecular regulation of ovule development is becoming available. This is accompanied by an increase in our understanding of ovule development in other model species such as rice (Figure 3). Comparing the knowledge that we have obtained from Arabidopsis with the data obtained from other species will allow us to ascertain the extent of conservation of the regulatory

Acknowledgements

We thank Gerco Angenent for providing pictures of the Petunia fbp7;fbp11 co-suppression mutant.

References (61)

  • T. Honma et al.

    Complexes of MADS-box proteins are sufficient to convert leaves into floral organs

    Nature

    (2001)
  • J.L. Bowman

    Genes directing flower development in Arabidopsis

    Plant Cell

    (1989)
  • G. Theissen

    Classification and phylogeny of the MADS-box multigene family suggest defined roles of MADS-box gene subfamilies in the morphological evolution of eukaryotes

    J. Mol. Evol.

    (1996)
  • K. Robinson-Beers

    Ovule development in wild-type Arabidopsis and two female-sterile mutants

    Plant Cell

    (1992)
  • Z. Modrusan

    Homeotic transformation of ovules into carpel-like structures in Arabidopsis

    Plant Cell

    (1994)
  • A. Ray

    Arabidopsis floral homeotic gene BELL1 (BEL1) controls ovule development through negative regulation of AGAMOUS gene (AG)

    Proc. Natl. Acad. Sci. U. S. A.

    (1994)
  • G.C. Angenent

    A novel class of MADS-box genes is involved in ovule development in petunia

    Plant Cell

    (1995)
  • S. Ferrario

    The MADS box gene FBP2 is required for SEPALLATA function in petunia

    Plant Cell

    (2003)
  • R.G. Immink

    Analysis of the Petunia MADS-box transcription factor family

    Mol. Genet. Genomics

    (2003)
  • M. Vandenbussche

    Toward the analysis of the petunia MADS box gene family by reverse and forward transposon insertion mutagenesis approaches: B, C, and D floral organ identity functions require SEPALLATA-like MADS box genes in petunia

    Plant Cell

    (2003)
  • L. Dreni

    The D-lineage MADS-box gene OsMADS13 controls ovule identity in rice

    Plant J.

    (2007)
  • R. Favaro

    Ovule-specific MADS-box proteins have conserved protein-protein interactions in monocot and dicot plants

    Mol. Genet. Genomics

    (2002)
  • E.M. Kramer

    Patterns of gene duplication and functional evolution during the diversification of the AGAMOUS subfamily of MADS box genes in angiosperms

    Genetics

    (2004)
  • T. Yamaguchi et al.

    Function and diversification of MADS-box genes in rice

    Scientific World Journal

    (2006)
  • T. Chiurugwi

    Floral meristem indeterminacy depends on flower position and is facilitated by acarpellate gynoecium development in Impatiens balsamina

    New Phytol.

    (2007)
  • H. Nakagawa

    The Petunia ortholog of Arabidopsis SUPERMAN plays a distinct role in floral organ morphogenesis

    Plant Cell

    (2004)
  • S. Yamaki

    Gypsy embryo specifies ovule curvature by regulating ovule/integument development in rice

    Planta

    (2005)
  • R. Sablowski

    Flowering and determinacy in Arabidopsis

    J. Exp. Bot

    (2007)
  • S. Ferrario

    Control of floral meristem determinacy in Petunia by MADS-box transcription factors

    Plant Physiol.

    (2006)
  • M.F. Yanofsky

    The protein encoded by the Arabidopsis homeotic gene AGAMOUS resembles transcription

    Nature

    (1990)

    • Cited by (0)

    View full text
    Copyright © 2008 Elsevier Ltd. All rights reserved.