tla1, a DNA insertional transformant of the green alga Chlamydomonas reinhardtii with a truncated light-harvesting chlorophyll antenna size

• Published in: Planta Vol. 217; no. 1; pp. 49 - 59
• Main Authors: Polle, Juergen E.W., Kanakagiri, Sarada-Devi, Melis, Anastasios
• Format: Journal Article
• Language: English
• Published: Berlin Springer-Verlag 01.05.2003; Springer; Springer Nature B.V
• Subjects: Algae; Algal Proteins - genetics; Algal Proteins - metabolism; Amino acids; Animals; Aquatic plants; Arginine - metabolism; Biological and medical sciences; Blotting, Southern; Chlamydomonas reinhardtii - genetics; Chlamydomonas reinhardtii - growth & development; Chlamydomonas reinhardtii - metabolism; Chlorophyll; Chlorophyll - metabolism; Chlorophylls; Cultured cells; Deoxyribonucleic acid; DNA; DNA Transposable Elements - genetics; Fluorescence; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation - radiation effects; Light; Light intensity; Luminous intensity; Metabolism; Molecular Sequence Data; Mutagenesis, Insertional; Mutation; Oxygen - metabolism; Phenotype; Phenotypes; Photons; Photosynthesis; Photosynthesis - genetics; Photosynthesis - radiation effects; Photosynthesis, respiration. Anabolism, catabolism; Plant physiology and development; Productivity; Thylakoids; Chlorophyll; Solar conversion efficiency; Light harvesting system; Algae; Deficiency; DNA insertional mutagenesis; Chlorophyll-deficient mutant; Chlorophyceae; Chlamydomonas; Chlorophyta; Chlamydomonas reinhardtii; Insertion mutation; Light-harvesting antenna; Photosynthesis; Thallophyta
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-002-0968-1

DNA insertional mutagenesis and screening of the green alga Chlamydomonas reinhardtii was employed to isolate tla1, a stable transformant having a truncated light-harvesting chlorophyll antenna size. Molecular analysis showed a single plasmid insertion into an open reading frame of the nuclear genome corresponding to a novel gene (Tla1) that encodes a protein of 213 amino acids. Genetic analysis showed co-segregation of plasmid and tla1 phenotype. Biochemical analyses showed the tla1 mutant to be chlorophyll deficient, with a functional chlorophyll antenna size of photosystem I and photosystem II being about 50% and 65% of that of the wild type, respectively. It contained a correspondingly lower amount of light-harvesting proteins than the wild type and had lower steady-state levels of Lhcb mRNA. The tla1 strain required a higher light intensity for the saturation of photosynthesis and showed greater solar conversion efficiencies and a higher photosynthetic productivity than the wild type under mass culture conditions. Results are discussed in terms of the tla1 mutation, its phenotype, and the role played by the Tla1 gene in the regulation of the photosynthetic chlorophyll antenna size in C. reinhardtii.