Plant physiology (Bethesda), 2012-12, Vol.160 (4), p.1923-1939
2012
Details
- Autor(en) / Beteiligte
- Titel
- LCAA, a Novel Factor Required for Magnesium Protoporphyrin Monomethylester Cyclase Accumulation and Feedback Control of Aminolevulinic Acid Biosynthesis in Tobacco
- Ist Teil von
- Plant physiology (Bethesda), 2012-12, Vol.160 (4), p.1923-1939
- Ort / Verlag
- Rockville, MD: American Society of Plant Biologists
- Erscheinungsjahr
- 2012
- Link zum Volltext
- Quelle
- EZB Electronic Journals Library
- Beschreibungen/Notizen
- Low Chlorophyll Accumulation A (LCAA) antisense plants were obtained from a screen for genes whose partial down-regulation results in a strong chlorophyll deficiency in tobacco (Nicotiana tabacum). The LCAA mutants are affected in a plastid-localized protein of unknown function, which is conserved in cyanobacteria and all photosynthetic eukaryotes. They suffer from drastically reduced lightharvesting complex (LHC) contents, while the accumulation of all other photosynthetic complexes per leaf area is less affected. As the disturbed accumulation of LHC proteins could be either attributable to a defect in LHC biogenesis itself or to a bottleneck in chlorophyll biosynthesis, chlorophyll synthesis rates and chlorophyll synthesis intermediates were measured. LCAA antisense plants accumulate magnesium (Mg) protoporphyrin monomethylester and contain reduced protochlorophyllide levels and a reduced content of CHL27, a subunit of the Mg protoporphyrin monomethylester cyclase. Bimolecular fluorescence complementation assays confirm a direct interaction between LCAA and CHL27. 5-Aminolevulinic acid synthesis rates are increased and correlate with an increased content of glutamyl-transfer RNA reductase. We suggest that LCAA encodes an additional subunit of the Mg protoporphyrin monomethylester cyclase, is required for the stability of CHL27, and contributes to feedback-control of 5-aminolevulinic acid biosynthesis, the rate-limiting step of chlorophyll biosynthesis.
- Sprache
- Englisch
- Identifikatoren
- ISSN: 0032-0889, 1532-2548eISSN: 1532-2548DOI: 10.1104/pp.112.206045Titel-ID: cdi_proquest_miscellaneous_1237505697
- Format
- –
- Schlagworte
- Amino Acid Sequence, Aminolevulinic Acid - metabolism, BIOENERGETICS AND PHOTOSYNTHESIS, Biological and medical sciences, Biosynthesis, Chlorophyll - metabolism, Chlorophyll A, Chlorophylls, Chloroplasts, Conserved Sequence, Cytochromes, Enzymes, Evolution, Molecular, Feedback, Physiological, Fluorescence, Fundamental and applied biological sciences. Psychology, Gene Expression Regulation, Plant, Health aspects, Intramolecular Oxidoreductases - chemistry, Intramolecular Oxidoreductases - metabolism, Light-Harvesting Protein Complexes - metabolism, Magnesium in the body, Molecular Sequence Data, Nicotiana - enzymology, Nicotiana - genetics, Nicotiana - growth & development, Oxidation-Reduction, Phenotype, Photosynthesis - genetics, Physiological aspects, Phytochemistry, Plant physiology and development, Plant Proteins - metabolism, Plants, Plastids - metabolism, Porphyrins, Protein Transport, Proteins, Protoporphyrins - metabolism, RNA, Antisense - metabolism, Sequence Alignment, Tetrapyrroles, Tetrapyrroles - metabolism, Thylakoids, Tobacco (Plant)