Abstract
BackgroundDrought stress negatively affects plant growth and productivity. Plants sense soil drought at the root level but the underlying mechanisms remain unclear. At the cell level, we aim to reveal the short-term root perception of drought stress through membrane dynamics.ResultsIn our study, 15 Medicago truncatula accessions were exposed to a polyethylene glycol (PEG)-induced drought stress, leading to contrasted ecophysiological responses, in particular related to root architecture plasticity. In the reference accession Jemalong A17, identified as drought susceptible, we analyzed lateral roots by imaging of membrane-localized fluorescent probes using confocal microscopy. We found that PEG stimulated endocytosis especially in cells belonging to the growth differentiation zone (GDZ). The mapping of membrane lipid order in cells along the root apex showed that membranes of root cap cells were more ordered than those of more differentiated cells. Moreover, PEG triggered a significant increase in membrane lipid order of rhizodermal cells from the GDZ. We initiated the membrane analysis in the drought resistant accession HM298, which did not reveal such membrane modifications in response to PEG.ConclusionsOur data demonstrated that the plasma membranes of root cells from a susceptible genotype perceived drought stress by modulating their physical state both via a stimulation of endocytosis and a modification of the degree of lipid order, which could be proposed as mechanisms required for signal transduction.
Highlights
Drought stress negatively affects plant growth and productivity
polyethylene glycol (PEG) applied to a core-collection of Medicago truncatula revealed accession-dependent responses A panel of 15 Medicago accessions (Table 1 and Additional file 1: Table S1) was evaluated for its response to PEG-induced drought stress
This panel included 12 inbred lines out of the 16 that constitutes a nested core collection representative of Medicago truncatula genetic diversity (CC16, [26]), the Jemalong A17 reference accession used for the genome sequencing effort, and two accessions (HM026 and HM298) that were previously tested in an in vitro leaf dehydration assay using PEG and that displayed a contrasted response [27]
Summary
Drought stress negatively affects plant growth and productivity. Plants sense soil drought at the root level but the underlying mechanisms remain unclear. We aim to reveal the short-term root perception of drought stress through membrane dynamics. Plants have developed several strategies under natural selection, including numerous changes at the morphological, physiological, and biochemical levels in all plant organs (for review [3]). Plant roots are essential organs that provide the plant with water and nutrients. They represent the primary site for sensing drought and initiating signaling cascades to the whole plant for adequate responses. Due to limitations on root accessibility, the influence of drought on this organ has been much less studied than aerial plant parts.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
