DGDG and Glycolipids in Plants and Algae

Abstract

Photosynthetic organelles in plants and algae are characterized by the high abundance of glycolipids, including the galactolipids mono- and digalactosyldiacylglycerol (MGDG, DGDG) and the sulfolipid sulfoquinovosyldiacylglycerol (SQDG). Glycolipids are crucial to maintain an optimal efficiency of photosynthesis. During phosphate limitation, the amounts of DGDG and SQDG increase in the plastids of plants, and DGDG is exported to extraplastidial membranes to replace phospholipids. Algae often use betaine lipids as surrogate for phospholipids. Glucuronosyldiacylglycerol (GlcADG) is a further glycolipid that accumulates under phosphate deprived conditions. In contrast to plants, a number of eukaryotic algae contain very long chain polyunsaturated fatty acids of 20 or more carbon atoms in their glycolipids. The pathways and genes for galactolipid and sulfolipid synthesis are largely conserved between plants, Chlorophyta, Rhodophyta and algae with complex plastids derived from secondary or tertiary endosymbiosis. However, the relative contribution of the endoplasmic reticulum- and plastid-derived lipid pathways for glycolipid synthesis varies between plants and algae. The genes for glycolipid synthesis encode precursor proteins imported into the photosynthetic organelles. While most eukaryotic algae contain the plant-like galactolipid (MGD1, DGD1) and sulfolipid (SQD1, SQD2) synthases, the red alga Cyanidioschyzon harbors a cyanobacterium-type DGDG synthase (DgdA), and the amoeba Paulinella, derived from a more recent endosymbiosis event, contains cyanobacterium-type enzymes for MGDG and DGDG synthesis (MgdA, MgdE, DgdA).

Nutrient availability affects the polar lipidome of Halimione portulacoides leaves cultured in hydroponics

“…The upregulation of genes encoding GLs synthase (ex. DGD1, DGD2, MGD2/ MGD3) which activate additional GLs biosynthetic pathways in plants under P-limited conditions [71][72][73] could explain the changes observed in H. portulacoides' GL profile under the conditions of low P-input. Previous studies, in both plants and microalgae, demonstrated that the availability of N also affects the morphology and function of chloroplasts in superior plants and microalgae [74][75][76][77][78] and an accumulation of GLs can be therefore observed under both N-and P-limitation.…”

“…Therefore, at low-input concentrations of P, the leaves of H. portulacoides display a low degree of lipidome remodulation associated with significant changes in GLs. In plants, GLs are typically found in chloroplast thylakoids, being their major lipid constituents, but under P-limited conditions, GLs (particularly DGDG) can partially replace PLs in extra-plastidial membranes 71 . The upregulation of genes encoding GLs synthase (ex.…”

Fatty Acid Composition, Phospholipid Molecules, and Bioactivities of Lipids of the Mud Crab Scylla paramamosain

“…In S. paramamosain, the content of polar lipids containing glycolipids and phospholipids was 40.02% of the total lipids. Glycolipids are the main component of photosynthetic organelles in plants, while phospholipids are present in the cell membranes of both animals and plants [29,30]. In this study, we focused on determining phospholipid structures using molecular analysis.…”

Antimicrobial lead compounds from marine plants

“…Marine algae show three types of glycolipids; MGDG e Mono Galactosyl Di Glyceride, DGDG e Di Galactosyl Di Glyceride and SQDG e Sulfono Quinovosyl Dipalmitoyl Glyceride, found in chloroplasts of algae. MGDG, DGDG are abundant in thylakoid membrane playing a significant role in photosynthesis [118]. SGDGs from Sargassum vulgare brown alga showed antiviral activity against HSV1 and V2 (Herpes Simplex Virus 1 and 2) viruses [119].…”