Cell-cell adhesion in plants is known to be regulated by pectins, and levels of homogalacturonan (HG; the main component of pectins) within the cell wall have generally been linked to cell adhesion. But how is cell-cell adhesion maintained and regulated in the face of the dynamic cell wall remodelling that takes place during cell growth and division? Here, Grégory Mouille and colleagues investigate this issue (p. ). Using a cell adhesion defect suppressor screen, they identify a putative O-fucosyltransferase – an enzyme that mediates the transfer of sugar residues onto substrates – that regulates cell adhesion in Arabidopsis thaliana. They further reveal that mutations in the gene encoding this enzyme or another putative O-fucosyltransferase perturb cell adhesion. Importantly, a comparison of mutant and suppressor lines suggests that cell adhesion does not rely on HG content per se. Based on their findings, the authors propose a model in which a pectin-related signalling pathway, rather than simply HG levels, contributes to the control and maintenance of cell adhesion during plant growth and development.
