Journal Article

Mycorrhizal lipochitinoligosaccharides (LCOs) depolarize root hairs of Medicago truncatula

Geiger, Dietmar, Hedrich, Rainer, Cottaz, Sylvain, Roelfsema, M. Rob G., Hürter, Anna-Lena, Fort, Sébastien

2018

Overview

Arbuscular Mycorrhiza and Root Nodule Symbiosis are symbiotic interactions with a high benefit for plant growth and crop production. Thus, it is of great interest to understand the developmental process of these symbioses in detail. We analysed very early symbiotic responses of Medicago truncatula root hair cells, by stimulation with lipochitinoligosaccharides specific for the induction of nodules (Nod-LCOs), or the interaction with mycorrhiza (Myc-LCOs). Intracellular micro electrodes were used, in combination with Ca2+ sensitive reporter dyes, to study the relations between cytosolic Ca2+ signals and membrane potential changes. We found that sulfated Myc- as well as Nod-LCOs initiate a membrane depolarization, which depends on the chemical composition of these signaling molecules, as well as the genotype of the plants that were studied. A successive application of sulfated Myc-LCOs and Nod-LCOs resulted only in a single transient depolarization, indicating that Myc-LCOs can repress plasma membrane responses to Nod-LCOs. In contrast to current models, the Nod-LCO-induced depolarization precedes changes in the cytosolic Ca2+ level of root hair cells. The Nod-LCO induced membrane depolarization thus is most likely independent of cytosolic Ca2+ signals and nuclear Ca2+ spiking.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Acids / Agricultural production / Alfalfa / Analysis / Arbuscular mycorrhizas / Biology and Life Sciences / Biophysics / Botanics / Calcium ions / Calcium signalling / Cell Membrane - drug effects / Cell Membrane - metabolism / Chemical composition / Chitin - chemistry / Crop production / Depolarization / Ecology, environment / Engineering and Technology / Fungal Polysaccharides - chemistry / Fungal Polysaccharides - pharmacology / Fungi / Gene expression / Genotypes / Hair cells / Kinases / Legumes / Life Sciences / Medicago truncatula / Medicago truncatula - cytology / Medicago truncatula - drug effects / Medicine and Health Sciences / Membrane potential / Membranes / Microbiology and Parasitology / Molecular chains / Myc protein / Mycology / Mycorrhizae - chemistry / Nodules / Oligosaccharides / Organic chemistry / Physiological aspects / Physiology / Plant growth / Plant Roots - cytology / Plant Roots - drug effects / Proteins / Research and Analysis Methods / Root hairs / Root nodules / Seeds / Symbiosis / Vegetal Biology