A receptor-like kinase mutant with absent endodermal diffusion barrier displays selective nutrient homeostasis defects

• Published in: eLife Vol. 3; p. e03115
• Main Authors: Pfister, Alexandre, Barberon, Marie, Alassimone, Julien, Kalmbach, Lothar, Lee, Yuree, Vermeer, Joop E M, Yamazaki, Misako, Li, Guowei, Maurel, Christophe, Takano, Junpei, Kamiya, Takehiro, Salt, David E, Roppolo, Daniele, Geldner, Niko
• Format: Journal Article
• Language: English
• Published: England eLife Sciences Publications Ltd 16-09-2014; eLife Sciences Publication; eLife Sciences Publications, Ltd
• Subjects: Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Biological Transport - genetics; Cell Biology; Cell Differentiation - genetics; COP9 Signalosome Complex; Defects; Deoxyribonucleic acid; Diffusion; DNA; Embedding; Gene Expression Profiling; Gene Expression Regulation, Plant; Genotype & phenotype; Homeostasis; Homeostasis - genetics; Kinases; Life Sciences; Lignin; Lipids - biosynthesis; Localization; Microscopy, Confocal; Mutation; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Nutrient uptake; Oligonucleotide Array Sequence Analysis; Plant Biology; plant nutrition; Plant Roots - cytology; Plant Roots - genetics; Plant Roots - metabolism; Plants, Genetically Modified; Plasma; polarity; Potassium - metabolism; Protein Kinases - genetics; Protein Kinases - metabolism; Proteins; Reverse Transcriptase Polymerase Chain Reaction; root biology; Vegetal Biology; Water - metabolism; plant nutrition; plant biology; cell biology; root biology; arabidopsis; polarity
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.03115

The endodermis represents the main barrier to extracellular diffusion in plant roots, and it is central to current models of plant nutrient uptake. Despite this, little is known about the genes setting up this endodermal barrier. In this study, we report the identification and characterization of a strong barrier mutant, schengen3 (sgn3). We observe a surprising ability of the mutant to maintain nutrient homeostasis, but demonstrate a major defect in maintaining sufficient levels of the macronutrient potassium. We show that SGN3/GASSHO1 is a receptor-like kinase that is necessary for localizing CASPARIAN STRIP DOMAIN PROTEINS (CASPs)--major players of endodermal differentiation--into an uninterrupted, ring-like domain. SGN3 appears to localize into a broader band, embedding growing CASP microdomains. The discovery of SGN3 strongly advances our ability to interrogate mechanisms of plant nutrient homeostasis and provides a novel actor for localized microdomain formation at the endodermal plasma membrane.