Ceramides mediate positional signals in Arabidopsis thaliana protoderm differentiation

• Published in: Development (Cambridge) Vol. 148; no. 2
• Main Authors: Nagata, Kenji, Ishikawa, Toshiki, Kawai-Yamada, Maki, Takahashi, Taku, Abe, Mitsutomo
• Format: Journal Article
• Language: English
• Published: England 25.01.2021
• Subjects: Arabidopsis - cytology; Arabidopsis - genetics; Arabidopsis Proteins - chemistry; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Cell Differentiation - genetics; Cell Lineage; Cell Membrane - metabolism; Ceramides - metabolism; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Green Fluorescent Proteins - metabolism; Ligands; Models, Biological; Plant Epidermis - cytology; Plant Epidermis - genetics; Plant Roots - embryology; Plant Roots - metabolism; Protein Domains; Protein Stability; Sphingolipids - metabolism; Ceramide; Epidermis; ATML1; Positional signal; VLCFA
• ISSN: 0950-1991; 1477-9129
• DOI: 10.1242/dev.194969

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