Abstract

Lipid rafts, cholesterol- and sphingolipid-rich microdomains, are critical regulators of membrane protein function and signaling, yet their presence and role in plant mitochondrial membranes, particularly under stress conditions, remain a subject of investigation. This study aimed to analyze the organization and biophysical properties of lipid raft structures within the mitochondrial membranes of halophytes, plants adapted to high-salinity environments. Using the fluorescent probe Laurdan and generalized polarization (GP) analysis via fluorescence microscopy, we assessed the degree of lipid order within detergent-resistant membrane (DRM) fractions isolated from halophyte mitochondria. Our findings confirm the existence of distinct, highly ordered lipid microdomains in the mitochondrial membranes, characterized by significantly higher GP values compared to the bulk membrane. This elevated lipid order suggests a unique lipid composition, likely enriched in sterols and saturated phospholipids, which may be crucial for maintaining mitochondrial integrity and function under the osmotic and ionic stress imposed by high salinity. The results provide novel insights into the structural plasticity of plant mitochondrial membranes and highlight the potential role of lipid rafts as key components in the stress adaptation mechanisms of halophytes.