Biology subjects

Guerringue, Y.

Publications and source records attributed to Guerringue, Y..

3 recordsLinked to original sources

bioRxiv2025

The Rapid Mechanically Activated (RMA) channel transduces increases in plasma membrane tension into transient calcium influx

O_LIPlants respond to mechanical stimuli by a rapid increase in cytosolic calcium. The intensity and kinetics of the calcium changes define calcium signatures important for biological responses . In this study, we determine the properties of a calcium permeable force-gated channel localized at the plasma membrane called Rapid Mechanically Activated (RMA). C_LIO_LIUsing patch-clamp and pressure-clamp, we characterized the kinetics of activation and inactivation of RMA channel upon stimulation by pulses of pressure applied onto the plasma membrane. Combining repetitive pressure pulse protocols at different frequencies with modeling, we investigated the channels capacity to transduce high frequency mechanical stimuli. C_LIO_LIRMA channel rapidly activates in response to membrane tension, then it inactivates during prolonged stimulation. Upon repeated stimulations, RMA current amplitude decreases irreversibly indicating that undergoes adaptation. The channel kinetics may be modeled with four chemical states and the model predicts that it behaves as a pass band filter in the 10 Hz - 1 kHz range. C_LIO_LIIn conclusion, due to its activation/inactivation characteristics, RMA channel is a candidate to mediate cytosolic calcium signaling in response to mechano-stimulation. Its adaptation and filtering properties suggest its involvement in the transduction of high frequency mechanical stimulation such as those produced by insects vibrations. C_LI

plant biology↗

bioRxiv2023

Local compression of the root in a microfluidic device triggers a calcium signal

Throughout their life, plant root are submitted to mechanical stresses due to pressure exerted by the soil. So far, few studies addressed root cell deformation and calcium signaling elicited by soil compression. In this study, we designed a microchip inspired by pneumatic microvalve concept in order to deliver a lateral pressure to the root of a plant expressing the RGECO1-mTurquoise calcium reporter. Lateral pressure applied on the root induced a moderate elastic deformation of root cortical cells and elicited a multicomponent calcium signal at the onset of the pressure pulse, followed by a second one at the release of the pressure. This indicates that straining rather than stressing of tissues is relevant to trigger the calcium signal. The calcium elevation was restricted to the tissue under pressure and did not propagate. Additionally, the calcium signals exhibited a remarkable attenuation upon repetitive stimulations. Highlights- A microvalve concept mimicking lateral soil pressure was developed. - Non-damaging lateral compression of the root induces an elastic deformation of cortical cells. - A multicomponent calcium signal is elicited at the onset of a pressure pulse and upon release of the pressure. - Straining rather than stressing of tissues is relevant to trigger the calcium signal. - The calcium signal is localized at the tissue under pressure and does not propagate. - Calcium signals exhibit a remarkable attenuation upon repetitive stimulations.

plant biology↗

bioRxiv2017

Karrikin-sensing protein KAI2 is a new player in regulating root growth patterns

Roots form highly complex systems varying in growth direction and branching pattern to forage for nutrients efficiently. Here mutations in the KAI2 (KARRIKIN INSENSITIVE) /{beta}-fold hydrolase and the MAX2 (MORE AXILLARY GROWTH 2) F-box leucine-rich protein, which together perceive karrikins (smoke-derived butenolides), caused alteration in root growth direction (root skewing and waving) of Arabidopsis thaliana. This exaggerated root skewing was independent of endogenous strigolactone perception by the D14 /{beta}-fold hydrolase and MAX2. Thus KAI2/MAX2s regulation of root growth may be through perception of endogenous KAI2-ligands, which have yet to be identified. Degradation targets of the KAI2/MAX2 complex, SMAX1 (SUPPRESSOR OF MAX2-1) and SMXL6,7,8 (SUPPRESSOR OF MAX2-1-LIKE) are also involved in the regulation of root skewing. Genetic data reveal a new potential target for degradation, as mutation in the SKS3 (SKU5 similar) but not the SKU5/SKS17 root plasma membrane glycoprotein suppresses the exaggerated root skewing induced by the lack of MAX2. In Arabidopsis thaliana therefore, the KAI2 karrikin-sensing protein acts to limit root skewing, and we propose a mechanism involving root radial expansion as the mutants gravitropic and mechano-sensing responses remained largely unaffected.

plant biology↗