Pectin Demethylesterification Generates Platforms that Anchor Peroxidases to Remodel Plant Cell Wall Domains

Edith Francoz (1) , Philippe Ranocha (2) , Aurélie Le Ru (3) , Yves Y. Martinez (3) , Isabelle Fourquaux (4) , Alain Jauneau (3) , Christophe Dunand (2) , Vincent Burlat (2)

1 LRSV - Laboratoire de Recherche en Sciences Végétales
2 Dynamique et Evolution des Parois cellulaires végétales
3 FR AIB - Fédération de Recherche Agrobiosciences, Interactions et Biodiversité
4 CMEAB - Centre de Microscopie Électronique Appliquée à la Biologie

Plant cell walls are made of polysaccharidic-proteinaceous complex matrices. Molecular interactions governing their organization remain understudied. We take advantage of the highly dynamic cell walls of Arabidopsis seed mucilage secretory cells to propose a hierarchical multi-molecular interaction model within a cell wall domain. We show that the PECTINMETHYLESTERASE INHIBITOR6 activity creates a partially demethylesterified pectin pattern acting as a platform allowing positioning of PEROXIDASE36 in a remote primary cell wall domain during early development. This allows triggering the loosening of this domain during later development, in turn leading to proper physiological function upon mature seed imbibition and germination. We anticipate that this pioneer example of molecular scaffold within a cell wall domain is more widespread through other combinations of the individual molecular players all belonging to large multigenic families. These results highlight the role of cell wall polysaccharide-protein interactions in the organization of cell wall domains.

Mots clés: pectin methylesterase inhibitor; homogalacturonan methylesterification; FRET-FLIM immunofluorescence; class III peroxidase; Arabidopsis thaliana; plant cell wall domain; protein-polysaccharide interaction; seed mucilage secretory cells; PRX36; PMEI6

Domaines: Botanique; Biologie moléculaire

Edith Francoz, Philippe Ranocha, Aurélie Le Ru, Yves Y. Martinez, Isabelle Fourquaux, et al.. Pectin Demethylesterification Generates Platforms that Anchor Peroxidases to Remodel Plant Cell Wall Domains. Developmental Cell, 2019, 48 (2), pp.261-276.e8. ⟨10.1016/j.devcel.2018.11.016⟩. ⟨hal-02363268⟩