Dynamic Membrane Lipid Changes in Physcomitrium patens Reveal Developmental and Environmental Adaptations.

Gautam, Deepshila; Behera, Jyoti R.; Shinde, Suhas; Pattada, Shivakumar D.; Roth, Mary; Yao, Libin; Welti, Ruth; Kilaru, Aruna

Simple Summary: Membrane lipid composition is crucial for growth and adaptation in organisms. This study examines the changes in membrane lipids during the development of the moss Physcomitrium patens. We found that during vegetative stages, especially in the protonema, the moss exhibits high lipid content and a significant presence of very long-chain polyunsaturated fatty acids, like arachidonic acid (C20:4). These lipids, not found in vascular plants, likely help mosses adapt to cold climates and other stresses by maintaining membrane fluidity. Additionally, galactolipids such as monogalactosyldiacylglycerol are abundant, supporting chloroplast formation. As the moss transitions to the sporophyte stage, lipid composition shifts. Galactolipids decrease, while phospholipids, particularly phosphatidylcholine (PC) and phosphatidic acid increase. These changes are linked to stress protection and gametangia formation. The increased PC relative to phosphatidylethanolamine in sporophytes suggests a protective mechanism against environmental stresses. Our findings highlight the importance of membrane lipids in moss development and adaptation. Future research should explore the role of lipids in stress responses and evolutionary adaptations in bryophytes, offering insights into plant lipid biology and evolution. Membrane lipid composition is critical for an organism's growth, adaptation, and functionality. Mosses, as early non-vascular land colonizers, show significant adaptations and changes, but their dynamic membrane lipid alterations remain unexplored. Here, we investigated the temporal changes in membrane lipid composition of the moss Physcomitrium patens during five developmental stages and analyzed the acyl content and composition of the lipids. We observed a gradual decrease in total lipid content from the filamentous protonema stage to the reproductive sporophytes. Notably, we found significant levels of very long-chain polyunsaturated fatty acids, particularly arachidonic acid (C20:4), which are not reported in vascular plants and may aid mosses in cold and abiotic stress adaptation. During vegetative stages, we noted high levels of galactolipids, especially monogalactosyldiacylglycerol, associated with chloroplast biogenesis. In contrast, sporophytes displayed reduced galactolipids and elevated phosphatidylcholine and phosphatidic acid, which are linked to membrane integrity and environmental stress protection. Additionally, we observed a gradual decline in the average double bond index across all lipid classes from the protonema stage to the gametophyte stage. Overall, our findings highlight the dynamic nature of membrane lipid composition during moss development, which might contribute to its adaptation to diverse growth conditions, reproductive processes, and environmental challenges.

UNSATURATED fatty acids; CHLOROPLAST formation; ARACHIDONIC acid; PHOSPHATIDIC acids; FATTY acids

Biology (2079-7737), 2024, Vol 13, Issue 9, p726

2079-7737

Academic Journal

10.3390/biology13090726