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The sticky tale of seed coat mucilages: production, genetics, and role in seed germination and dispersal

Published online by Cambridge University Press:  26 September 2011

Tamara L. Western
Tamara L. Western*
Affiliation:
Biology Department and Developmental Biology Research Initiative, McGill University, 1205 avenue Docteur Penfield, Montreal, QC H3A 1B1, Canada
*
*Correspondence Fax: 1-514-398-5069 Email: [email protected]
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Abstract

The production of hydrophilic mucilages by the seed coat or pericarp, which are released upon seed hydration, is a commonly found adaptation in angiosperms, known as myxodiaspory. These are composed primarily of pectins and hemicelluloses that undergo substantive swelling upon hydration. Synthesized in the Golgi apparatus and secreted to an apoplastic space via secretory vesicles, mucilages can also contain cellulose microfibrils or cellulosic fibres that are synthesized at the plasma membrane in association with microtubules. Investigation of mucilage production in, and differentiation of, the mucilage secretory cells of the genetic model plant Arabidopsis thaliana has identified a number of regulatory genes and enzymes involved in pectin synthesis and secretion, in muro pectin modification and secondary cell wall synthesis. Studies of the role of mucilages in both a number of species and in Arabidopsis mutants affected in its production suggest that they have multiple ecological roles. These include facilitation of seed hydration, mediation of germination under waterlogged conditions, prevention of seed dispersal or predation by adherence to soil, and promotion of seed dispersal by attachment to animals. The precise role of mucilages appears to be dependent on species and their environmental context.

Keywords

Arabidopsisgerminationmucilagepectinseed coatseed dispersaltesta
Type
Review Papers
Information
Seed Science Research , Volume 22 , Issue 1 , March 2012 , pp. 1 - 25
Copyright
Copyright © Cambridge University Press 2011

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