Xyloglucan Metabolism Differentially Impacts the Cell Wall Characteristics of the Endosperm and Embryo during Arabidopsis Seed Germination

Abstract : Cell wall remodeling is an essential mechanism for the regulation of plant growth and architecture, and xyloglucans (XyGs), the major hemicellulose, are often considered as spacers of cellulose microfibrils during growth. In the seed, the activity of cell wall enzymes plays a critical role in germination by enabling embryo cell expansion leading to radicle protrusion, as well as endosperm weakening prior to its rupture. A screen for Arabidopsis (Arabidopsis thaliana) mutants affected in the hormonal control of germination identified a mutant, xyl1, able to germinate on paclobutrazol, an inhibitor of gibberellin biosynthesis. This mutant also exhibited reduced dormancy and increased resistance to high temperature. The XYL1 locus encodes an alpha-xylosidase required for XyG maturation through the trimming of Xyl. The xyl1 mutant phenotypes were associated with modifications to endosperm cell wall composition that likely impact on its resistance, as further demonstrated by the restoration of normal germination characteristics by endosperm-specific XYL1 expression. The absence of phenotypes in mutants defective for other glycosidases, which trim Gal or Fuc, suggests that XYL1 plays the major role in this process. Finally, the decreased XyG abundance in hypocotyl longitudinal cell walls of germinating embryos indicates a potential role in cell wall loosening and anisotropic growth together with pectin de-methylesterification.
Type de document :
Article dans une revue
Plant Physiology, American Society of Plant Biologists, 2016, 170, pp.1367--80. 〈10.1104/pp.15.01312〉
Liste complète des métadonnées

https://hal-agroparistech.archives-ouvertes.fr/hal-01563909
Contributeur : Armelle Sielinou <>
Soumis le : mardi 18 juillet 2017 - 11:49:48
Dernière modification le : vendredi 20 octobre 2017 - 10:06:23

Lien texte intégral

Identifiants

Citation

J. Sechet, A. Frey, D. Effroy-Cuzzi, A. Berger, F. Perreau, et al.. Xyloglucan Metabolism Differentially Impacts the Cell Wall Characteristics of the Endosperm and Embryo during Arabidopsis Seed Germination. Plant Physiology, American Society of Plant Biologists, 2016, 170, pp.1367--80. 〈10.1104/pp.15.01312〉. 〈hal-01563909〉

Partager

Métriques

Consultations de la notice

76