A photorespiratory mutant of Chlamydomonas reinhardtii

Journal Article · Tue May 01 04:00:00 EDT 1990 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.93.1.231· OSTI ID:5961493

Suzuki, K; Marek, L F; Spalding, M H ^[1]

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1. Iowa State Univ., Ames (USA)

A mutant strain of Chlamydomonas reinhardtii, designated 18-7F, has been isolated and characterized. 18-7F requires a high CO{sub 2} concentration for photoautrophic growth in spite of the apparent induction of a functional CO{sub 2} concentrating mechanism in air-adapted cells. In 2% O{sub 2} the photosynthetic characteristics of 18-7F and wild type are similar. In 21% O{sub 2}, photosynthetic O{sub 2} evolution is severely inhibited in the mutant by preillumination in limiting CO{sub 2}, although the apparent photosynthetic affinity for inorganic carbon is similar in preilluminated cells and in cells incubated in the dark prior to O{sub 2} evolution measurements. Net CO{sub 2} uptake is also inhibited when the cells are exposed to air (21% O{sub 2}, 0.035% CO{sub 2}, balance N{sub 2}) for longer than a few minutes. ({sup 14}C)Phosphoglycolate accumulates within 5 minutes of photosynthetic {sup 14}CO{sub 2} fixation in cells of 18-7F. Phosphoglycolate does not accumulate in wild type. Phosphoglycolate phosphatase activity in extracts from air-adapted cells of 18-7F is 10 to 20% of that in wild-type Chlamydomonas. The activity of phosphoglycolate phosphatase in heterozygous diploids is intermediate between that of homozygous mutant and wild-type diploids. It was concluded that the high-CO{sub 2} requiring phenotype in 18-7F results from a phosphoglycolate phosphatase deficiency. Genetic analyses indicate that this deficiency results from a single-gene, nuclear mutation. We have named the locus pgp-1.

• OSTI ID: 5961493
• Journal Information: Plant Physiology; (USA), Journal Name: Plant Physiology; (USA) Vol. 93:1; ISSN 0032-0889; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALGAE
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CHLAMYDOMONAS
CHLOROPHYCOTA
ENZYME ACTIVITY
ENZYMES
ESTERASES
GENE MUTATIONS
HYDROLASES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
METABOLISM
MICROORGANISMS
MUTATIONS
OXIDES
OXYGEN COMPOUNDS
PHOSPHATASES
PHOSPHORUS COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PHYSIOLOGY
PLANTS
SYNTHESIS
TRACER TECHNIQUES
UNICELLULAR ALGAE