Boron-bridged GIPCs stabilize cell wall anchoring and PIN polar domains

Prof. Yuling Jiao published a paper in Cell with his collaborator.

Boron (B) is an essential plant micronutrient whose deficiency impairs global crop yields. Glycosylinositol phosphorylceramides (GIPCs) are major lipids in the plasma membrane (PM), and PIN-FORMED (PIN) proteins mediate polar auxin transport (PAT) via asymmetric PM localization. This study demonstrates that these components are functionally linked: B cross-links nearly all GIPC series, forming physical PM-cell wall attachments visualized as Hechtian strands. B-mediated cross-linking also restricts PIN2 lateral diffusion and endocytosis, stabilizing its polar domain formation via direct GIPC-PIN2 interaction. Phenotypic evidence supports this mechanism, as both B deficiency and impaired GIPC biosynthesis phenocopy high-orderpinmutants, showing defective PIN localization and diminished auxin maxima. Thus, the B-dependent, GIPC-mediated PM-cell wall continuum immobilizes PIN polar domains, enabling PAT and ensuring proper plant development and environmental adaptation.