Mechanism of toxicity of sulfur dioxide to plants. II. Inhibition of photosynthetic phosphate utilization in Chlorella pyrenoidosa

Journal Article · Mon Jan 01 04:00:00 EST 1968 · Proc., Annu. Meet., Air Pollut. Control Assoc.; (United States)

OSTI ID:5011029

McCormick, G C; Speaker, T J

Previous reports of acute toxic plant damage from sulfur dioxide exposure and earlier findings of sulfur dioxide inhibition of oxygen evolution led the authors to examine the effects of sulfur dioxide on algal phosphate utilization. Using thermostated pure cultures of the unicellular algae, Chlorella pyrenoidosa, they measured: (1) change in phosphate uptake spectrophotometrically as a function solely of sulfur dioxide dose; (2) simultaneous change in both phosphate uptake micromanometrically and oxygen evolution as a function of sulfur dioxide dose; and (3) the rate of phosphate uptake as a function of phosphate concentration in the presence of varying concentrations of sulfur dioxide. It was found that sulfur dioxide does indeed inhibit phosphate uptake; secondly, that the phosphate uptake inhibition is different from the inhibition of oxygen evolution in that phosphate uptake is more sensitive to dose of sulfur dioxide; that the phosphate inhibiting effect does not display a simple log-dose effect relationship; and that the estimated concentration of sulfur dioxide required to inhibit phosphate uptake completely is less than one-tenth that required to inhibit oxygen. These findings were interpreted as evidence for the existence of two mechanisms by which sulfur dioxide exerts a toxic effect on plants. The third study provided data suitable for analysis in the Lineweaver and Burk format and led to the conclusion that sulfur dioxide effect on phosphate uptake is a non-competitive process.

• OSTI ID: 5011029
• Journal Information: Proc., Annu. Meet., Air Pollut. Control Assoc.; (United States), Journal Name: Proc., Annu. Meet., Air Pollut. Control Assoc.; (United States) Vol. 68-38; ISSN PRAPA
• Country of Publication: United States
• Language: English

Related Subjects

560303* -- Chemicals Metabolism & Toxicology-- Plants-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALGAE
CHALCOGENIDES
CHEMICAL REACTIONS
CHLORELLA
DATA
EXPERIMENTAL DATA
INFORMATION
INJURIES
MICROORGANISMS
MINERAL CYCLING
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PLANTS
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
SYNTHESIS
TOXICITY
UNICELLULAR ALGAE
UPTAKE