Salicylic acid-mediated plasmodesmal closure via Remorin-dependent lipid organization

Abstract

Plasmodesmata (PD) are plant-specific membrane-lined channels that create cytoplasmic and membrane continuities between adjacent cells, thereby facilitating cell–cell communication and virus movement. Plant cells have evolved diverse mechanisms to regulate PD plasticity in response to numerous environmental stimuli. In particular, during defense against plant pathogens, the defense hormone, salicylic acid (SA), plays a crucial role in the regulation of PD permeability in a callose-dependent manner. Here, we uncover a mechanism by which plants restrict the spreading of virus and PD cargoes using SA signaling by increasing lipid order and closure of PD. We showed that exogenous SA application triggered the compartmentalization of lipid raft nanodomains through a modulation of the lipid raft-regulatory protein, Remorin (REM). Genetic studies, superresolution imaging, and transmission electron microscopy observation together demonstrated that Arabidopsis REM1.2 and REM1.3 are crucial for plasma membrane nanodomain assembly to control PD aperture and functionality. In addition, we also found that a 14-3-3 epsilon protein modulates REM clustering and membrane nanodomain compartmentalization through its direct interaction with REM proteins. This study unveils a molecular mechanism by which the key plant defense hormone, SA, triggers membrane lipid nanodomain reorganization, thereby regulating PD closure to impede virus spreading.

Treatment of Sweet Pepper with Stress Tolerance-Inducing Compounds Alleviates Salinity Stress Oxidative Damage by Mediating the Physio-Biochemical Activities and Antioxidant Systems

“…This beneficial effect could be due to the protective role of SA, yeast, and proline in plasma membrane stability and increasing soluble metabolite accumulation. A similar result was indicated by Ishikawa and Evans [56] and Huang et al [57], who reported that osmoregulators improve plant growth and yield under various stress conditions.…”

The bacterial quorum sensing signal DSF hijacks Arabidopsis thaliana sterol biosynthesis to suppress plant innate immunity

“…We, therefore, tested whether the increased sterol content could explain the DSF-induced phenotypes by treating Arabidopsis seedlings with Methyl-β-cyclodextrin (MβCD) in combination with DSF. MβCD is a widely used sterol-depleting agent that acts strictly at the membrane surface by binding to sterol with high affinity and remove sterol acutely within minutes, with demonstrated success in acute depletion of sterols in both plant and animal cells ( López et al, 2011 ; Gerbeau-Pissot et al, 2014 ; Valitova et al, 2014 ; Mahammad & Parmryd, 2015 ; Huang et al, 2019 ). Here, we found that MβCD fully blocked the DSF-induced inhibition of primary roots and root hairs, suggesting DSF’s opposite effects compared with MβCD on sterol perturbation in Arabidopsis .…”

Fumonisin B1-Induced Changes in Cotton Fiber Elongation Revealed by Sphingolipidomics and Proteomics

“…Analyses were conducted using an Exion ultra performance liquid chromatography (UPLC) (AB Sciex, CA, USA), coupled with Sciex QTRAP 6500 PLUS (AB Sciex, CA, USA), as reported previously [ 30 ]. Lipids were separated using a Phenomenex Luna 3 μm-silica column (Phenomenex, CA, USA) (internal diameter 150 × 2.0 mm) under the following conditions: mobile phase A (chloroform: methanol: ammonium hydroxide, 89.5:10:0.5) and mobile phase B (chloroform: methanol: ammonium hydroxide: water, 55:39: 0.5:5.5).…”