2025/07/25 by Marcel Dickmanns, Matthias Pöge, Peng Xu +7 · 1 voice · 3 citations
Biochemistry, Genetics and Molecular Biology · Medicine · Agricultural and Biological Sciences · #Advanced biosensing and bioanalysis techniques #Peptidase Inhibition and Analysis #Plant nutrient uptake and metabolism
paper · pdf · doi:10.1101/2025.07.24.666190
ABSTRACT Plasmodesmata are nanoscopic channels that traverse plant cell walls, establishing membrane and cytoplasmic continuity between adjacent cells to enable direct intercellular exchange. Although numerous components have been identified, their molecular organization and roles in controlling passage remain unclear. Here, we used cryo-electron tomography to resolve the in situ architecture of plasmodesmata in Physcomitrium patens across tissues and physiological states. We show how callose deposition at the cell wall shapes channel architecture to modulate permeability and identify helical protein assemblies formed by Multiple C2 domain and Transmembrane Proteins (MCTPs), which scaffold a central endoplasmic reticulum tubule and tether it to the plasma membrane. These findings define core architectural features of plasmodesmata and establish a structural framework for understanding how membrane, protein and cell wall components coordinate intercellular connectivity in plants.