Plant cell wall patterning and expansion mediated by protein-peptide-polysaccharide interaction

Science. 2023 Nov 10;382(6671):719-725. doi: 10.1126/science.adi4720. Epub 2023 Nov 9.


Assembly of cell wall polysaccharides into specific patterns is required for plant growth. A complex of RAPID ALKALINIZATION FACTOR 4 (RALF4) and its cell wall-anchored LEUCINE-RICH REPEAT EXTENSIN 8 (LRX8)-interacting protein is crucial for cell wall integrity during pollen tube growth, but its molecular connection with the cell wall is unknown. Here, we show that LRX8-RALF4 complexes adopt a heterotetrametric configuration in vivo, displaying a dendritic distribution. The LRX8-RALF4 complex specifically interacts with demethylesterified pectins in a charge-dependent manner through RALF4's polycationic surface. The LRX8-RALF4-pectin interaction exerts a condensing effect, patterning the cell wall's polymers into a reticulated network essential for wall integrity and expansion. Our work uncovers a dual structural and signaling role for RALF4 in pollen tube growth and in the assembly of complex extracellular polymers.

MeSH terms

  • Arabidopsis Proteins* / chemistry
  • Arabidopsis Proteins* / metabolism
  • Arabidopsis* / growth & development
  • Arabidopsis* / metabolism
  • Cell Wall* / chemistry
  • Cell Wall* / metabolism
  • Pectins* / chemistry
  • Pectins* / metabolism
  • Peptides / metabolism
  • Pollen Tube* / growth & development


  • Pectins
  • Peptides
  • RALF4 protein, Arabidopsis
  • Arabidopsis Proteins