Photosynthesis Research 73: 29–49, 2002. 31 © 2002 Kluwer Academic Publishers. Printed in the Netherlands. Personal perspective Following the path of carbon in photosynthesis: a personal story Andrew A. Benson Scripps Institution of Oceanography, La Jolla, CA 92093-0202, USA (e-mail:
[email protected]; fax: +1-858-534-7313) Received 14 September 2001; accepted in revised form 16 December 2001 Key words: James Bassham, Melvin Calvin, Martin Kamen, Jacques Mayaudon, phosphoglyceric acid, radioactive carbon-14, ribulose diphosphate (now called ribulose bisphosphate), Samuel Ruben, Hiroshi Tamiya Abstract Chronological recognition of the intermediates and mechanisms involved in photosynthetic carbon dioxide fixation is delineated. Sam Ruben and Martin Kamen’s development of application of radioactive carbon for the study of carbon dioxide fixation provided impetus and techniques for following the path of carbon in photosynthesis. Discovery The identity of the primary carboxylation enzyme and its identity with the major protein of photo- synthetic tissues (‘Fraction 1’ protein of Sam Wildman) is reviewed. Memories are dimmed by sixty years of exciting discoveries exploration in newer fields [see Benson 2002 (Annu Rev Plant Biol 53: 1–25), for research and perspectives beyond the early Berkeley days]. Formaldehyde theory for CO2 assimilation and physiologists. Its authoritative proponent, Adolph von Baeyer, and the absence of an equally feasible As I was born (1917), Richard Willstätter and Arthur mechanism sustained it. Robert Emerson (1929), too, Stoll were recording their detailed investigations of had devoted thought and experiments to the ideas of chlorophyll’s involvement in absorption of CO2 and E.C.C. Baly (Baly et al. 1927; Baly and Hood 1929; their search for photochemical production of form- see the book published in 1940), who had adopted the aldehyde (see Willstätter and Stoll [1918]: ‘Unter- formaldehyde concept.