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The Influence of Photosynthetic Factors and Metaholic Inhibitors on the Uptake of Phosphate in P‐Deficient Scenedesmus
Author(s) -
Kylin Anders
Publication year - 1966
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1966.tb07048.x
Subject(s) - phosphate , darkness , photosynthesis , scenedesmus , chemistry , respiration , biophysics , biochemistry , nuclear chemistry , botany , biology , algae
The cells used in the present investigation had a phosphate content of about 20 per cent as compared with the status in normal cultures. The uptake of phosphate during a period of 4 hours was determined at a pH of 6,5, kept constant with the aid of a citrate buffer. In the absence of CO 2 , light increased the uptake of phosphate with saturation around 14,000 erg/cm 2 s. With 5 per cent CO 2 in the air the relationship was more complicated, and the uptake of phosphate must he related to more than one process during active photosynthesis. The inhibiting effect of CO 2 in air was noticeable already at low concentrations both in light and in darkness. With the system used, this supports earlier indications for internal recycling of orthophosphate, CO 2 was inhibiting also in nitrogen in the light. Selenate in a concentration of 2 mM gave a slight and rather irregular inhibition.—Anaerobiosis had no effect in the light but gave a large decrease in the dark.—DNP (0.1 m M ) was somewhat more active in the dark than in the light. The lower concentrations tested had no effect in either case.—Menadione (0.1 m M ) inhibited strongly, and more in illuminated than in non‐illuminated cells.