Galactoglycerolipid Lipase PGD1 Is Involved in Thylakoid Membrane Remodeling in Response to Adverse Environmental Conditions in Chlamydomonas
| Autor: | Christoph Benning, Agnieszka Zienkiewicz, Ben F. Lucker, Barbara B. Sears, Zhi-Yan Du, David Kramer, Krzysztof Zienkiewicz, Tarryn E. Miller |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
0301 basic medicine Chloroplasts Mutant Chlamydomonas reinhardtii Plant Science macromolecular substances Environment Photosynthesis 01 natural sciences environment and public health Thylakoids Electron Transport 03 medical and health sciences chemistry.chemical_compound Stress Physiological polycyclic compounds Research Articles biology Galactolipids Chlamydomonas Algal Proteins food and beverages DCMU Cell Biology Lipase biology.organism_classification Electron transport chain Cell biology Chloroplast 030104 developmental biology chemistry Thylakoid lipids (amino acids peptides and proteins) 010606 plant biology & botany |
| Popis: | Photosynthesis occurs in the thylakoid membrane, where the predominant lipid is monogalactosyldiacylglycerol (MGDG). As environmental conditions change, photosynthetic membranes have to adjust. In this study, we used a loss-of-function Chlamydomonas reinhardtii mutant deficient in the MGDG-specific lipase PGD1 (PLASTID GALACTOGLYCEROLIPID DEGRADATION1) to investigate the link between MGDG turnover, chloroplast ultrastructure, and the production of reactive oxygen species (ROS) in response to different adverse environmental conditions. The pgd1 mutant showed altered MGDG abundance and acyl composition and altered abundance of photosynthesis complexes, with an increased PSII/PSI ratio. Transmission electron microscopy showed hyperstacking of the thylakoid grana in the pgd1 mutant. The mutant also exhibited increased ROS production during N deprivation and high light exposure. Supplementation with bicarbonate or treatment with the photosynthetic electron transport blocker DCMU protected the cells against oxidative stress in the light and reverted chlorosis of pgd1 cells during N deprivation. Furthermore, exposure to stress conditions such as cold and high osmolarity induced the expression of PGD1, and loss of PGD1 in the mutant led to increased ROS production and inhibited cell growth. These findings suggest that PGD1 plays essential roles in maintaining appropriate thylakoid membrane composition and structure, thereby affecting growth and stress tolerance when cells are challenged under adverse conditions. |
| Databáze: | OpenAIRE |
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