Mapping of Membrane Lipid Order in Root Apex Zones of Arabidopsis thaliana

Abstract

In this study, we used the fluorescence probe, Di-4-ANEPPDHQ, to map the distribution of membrane lipid order in the apical region of Arabidopsis roots. The generalized polarization (GP) value of Di-4-ANEPPDHQ-stained roots indicated the highest lipid order in the root transition zone (RTZ). The cortical cells have higher lipid order than the epidermal cells in same regions, while the developing root hairs show very prominent cell polarity with high lipid order in apical region. Moreover, the endosomes had lower lipid order than that of the plasma membrane (PM). Brefeldin A (BFA) treatment decreased the lipid order in both the plasma and endosomal membranes of epidermal cells in the RTZ. The lipid order of BFA-induced compartments became higher than that of the PM after BFA treatment in epidermal cells. Meanwhile, the polarly growing tips of root hairs did not show the same behavior. The lipid order of the PM remained unchanged, with higher values than that of the endosomes. This suggests that the lipid ordering in the PM was affected by recycling of endosomal vesicles in epidermal cells of the root apex transition zone but not in the root hairs of Arabidopsis.

Drought stress stimulates endocytosis and modifies membrane lipid order of rhizodermal cells of Medicago truncatula in a genotype-dependent manner

“…These lipid order-rich domains are thought to intervene in temporal and spatial organization of cell-specific processes. This differential lipid order was also observed in cell types of Arabidopsis root labeled with di-4-ANEPPDHQ dye [33]. We showed that in Medicago, as in Arabidopsis [33], cortical cells displayed higher lipid order than rhizodermal cells, and that cells from the distal root zones (RAM and RTZ; zones 1 and 2) had higher ordered membranes than the elongated and differentiated cells from the GDZ (zone 4).…”

“…To assess the effect of PEG-induced drought on membrane order, we used the di-4-ANEPPDHQ, a membrane fluorescent probe sensitive to local lipid packing, which has been previously used to monitor membrane lipid order in plant cells [30–33]. The spectral properties of the di-4-ANEPPDHQ dye are modified when the membrane environment is changed [34] and a General Polarization (GP) parameter, which defines proportionally the lipid order of the membrane, is calculated from dual-channel images recorded from green and red fluorescence emissions [35].…”

Phosphorylation-Mediated Dynamics of Nitrate Transceptor NRT1.1 Regulate Auxin Flux and Nitrate Signaling in Lateral Root Growth

“…3, C and D). Considering previous reports that the most highly ordered lipid structures in cells of the transition zone correspond with high auxin flux (Mancuso et al, 2007;Zhao et al, 2015;Baluška et al, 2018), we speculate that phosphorylated NRT1.1 may aggregate into the PM microdomain in a process triggered by LN, which might provide an efficient means for transporting auxin.…”

Cell stage appears critical for control of plasma membrane order in plant cells

“…Averaging the RGM of cells in specific root zones, we observed increasing values of RGM corresponding to a decreasing distribution of the level of PM order along growing tips of A. thaliana roots ( Figure 1B). Such highest PM order of the apical region was already observed in root epidermal cells 8 and could be related with the cytokinesis-induced formation of ordered domainenriched platforms. 9 These results suggest a correlation between plant cell PM order and cell differentiation.…”