The Path of Carbon in Photosynthesis, XI The Role of Glycolic Acid

Abstract

l4The products were i d e n t i e a i t o Cvhose observed i n C O2 photosynthesis.A major reaction anaerobically i n the dark resulted i n incorporation of cU. i n almost equal amounts i n the giycine and'serine reservoirs, When the algae were illuminated, a d i m i m t i m i n the amount of glycine was observed , Aerobic and anaerobic glycolic acid asslmilatior, was studied during photosynthesis. The CU l e v e l i n the sucrose and the intermediates of its * This work was sponsored by the United S t a t s s Atomic Energy Commission.To be published i n Physiologia P l a n t a m , uCRL-908 ABSTRACT synthesis varied with c1202 pressure in the gas used.14u and 2414 glycolic acids give similar distribution of radioactivity in the products. Hence, glycolic acid is assLmilated by paths other than those involving preliminary cleavage to C1 compounds.Phosphoglyceric acid isolated from the products of assimilation of both glycolic acids was degraded and found to be approximately equally labeled in its a and $ carbon atoms.

Photorespiration and Glycolate Metabolism: A Re-examination and Correlation of Some Previous Studies

“…Glv colic acid, as well as being ubiquitous in leaves, is one of the earliest products of photosynthesis particularly at lower CO., concentrations and higher O. concentrations (1,2,11,20,30). In addition, Ludwig and Krotkov (13) have provided evidence for some early photosynthetic product being oxidized to CO., in light.…”

The effect of oxygen on the reduction of CO2 to glycolic acid and other products during photosynthesis by Chlorella

“…The formation of labeled glycolic acid during photosynthesis with 14co 2 by Chlorella and by higher plants has been studied by Benson and Calvin (1950), Schou ~ ~· (1950), Wilson (1954), Wilson and Calvin (1955), Tolbert andZill (1956)• Tolbert (1958), Warburg (1960), and…”

Glycolate Pathway in Algae

“…Algae rapi(dly labeled glycolate, glycine, andl serinie (duiring ' 4C().0 photosynthesis (3,5,21). Fuirther, it has beeni reporte(d that glycolate-'4C was converted by .Scnedes)m(s to glycinie ainl(d serinie (24 ). It was kniowni that higher planits, rapidly, conlvert glycolate-1-'4C to hoth glycinie-1-14C and( serine-I-14C ani(l conivert glycolate-2-'C to glycine-2-14C andl serine-2, 3-'I4C (22,31,34,35 (32).…”