THE USE ISONICOTINYL HYDRAZIDE AS A METABOLIC INHIBITOR IN PHOTOSYNTHESIS,
Abstract
The photosynthetic production of glycollic acid in Chlorella was shown to be at a maximum at a low concentration of carbon dioxide and at light intensities approaching those required to saturate photosynthesis. Treatment with isonicotinyl hydrazide resulted in a three-fold stimulation of glycollic acid production. Studies with radioactive carbon dioxide show that glycine and serine were formed together with glycollate. When the radioactive carbon dioxide was replaced by non-radioactive carbon dioxide the compounds of the Calvin cycle lost radioactivity which was accumulated in either glycollate or sucrose suggesting that these were final products of the photosynthetic cycle. At higher concentrations of carbon dioxide sucrose is the main and predominant product but at low concentration of carbon dioxide a significant fraction of the carbon incorporated forms glycollate, glycine and serine. From the experiments with isonicotinyl hydrazide it would appear that as much as 70% of the carbon incorporated can result in glyoxylate and products therefrom. It is considered that these are derived by cleavage of the compound in the CALVIN cycle which is carboxylated to a greater and greater extent the higher the concentration of carbon dioxide. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1958
- Accession Number
- AD0617868
Entities
People
- C. P. Whittingham
- G. G. Pritchard
- M. Berminghan
- R. G. Hiller
Organizations
- Queen Mary University of London