Ceramides mediate positional signals in <i>Arabidopsis thaliana</i> protoderm differentiation

ABSTRACT The differentiation of distinct cell types in appropriate patterns is a fundamental process the development multicellular organisms. In Arabidopsis thaliana, protoderm/epidermis differentiates as single layer at outermost position. However, little known about molecular nature positional signals that achieve correct epidermal differentiation. Here, we propose very-long-chain fatty acid-containing ceramides (VLCFA-Cers) mediate by stimulating function ARABIDOPSIS THALIANA MERISTEM LAYER1 (ATML1), master regulator differentiation, during lateral root development. We show VLCFA-Cers, which are synthesized predominantly cells, bind to lipid-binding domain ATML1. Importantly, this type-specific protein-lipid association alters activity ATML1 protein and consequently restricts its expression through transcriptional feedback loop. Furthermore, establishment compartment, enriched with VLCFA-containing sphingolipids, outer membrane facing external environment may determinant protodermal fate. Taken together, our results indicate VLCFA-Cers play pivotal role directing mediating This article has an associated ‘The people behind papers’ interview.