Skip to main content

Discovery of the canonical Calvin–Benson cycle


It has been 65 years since the Calvin–Benson cycle was first formulated. In this paper, the development of the concepts that are critical to the cycle is traced and the contributions of Calvin, Benson, and Bassham are discussed. Some simplified views often found in text books such as ascending paper chromatography and the use of the “lollipop” for short labeling are discussed and further details given. Key discoveries that underpinned elucidation of the cycle such as the importance of sedoheptulose phosphate and ribulose 1,5-bisphosphate are described. The interchange of ideas between other researchers working on what is now called the pentose phosphate pathway and the development of the ideas of Calvin and Benson are explored while the gluconeogenic aspects of the cycle are emphasized. Concerns raised about anomalies of label distribution in glucose are considered. Other carbon metabolism pathways associated with the Calvin–Benson cycle are also described. Finally, there is a section describing the rift between Calvin and Benson.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2

Reproduced with permission from Bassham et al. (1954)

Fig. 3
Fig. 4
Fig. 5
Fig. 6

Reproduced with permission from Bassham et al. (1954)

Fig. 7

Reproduced with permission from Wilson and Calvin (1955)

Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13


  1. The name rubisco was coined by David Eisenberg in 1979 as a joke at Sam Wildman’s retirement party (Wildman 2002). The name emphasized the recent change in nomenclature from diphosphate to bisphosphate and the recent discovery that the enzyme is also an oxygenase (Bowes et al. 1971). In Sam’s next paper, he used the acronym rubisco, but soon after many variations in capitalization appeared. Style manuals provide clear guidelines for capitalization in this case. If the abbreviation is pronounced as a word (making it an acronym), and if it is so well known that people recognize the acronym more easily than the words it stands for, it is not capitalized (examples—laser and scuba). Wildman did not capitalize rubisco in his first publication using it (Wildman 1981). If an acronym is not quite so universally known but is more than four letters, the first letter (only) is capitalized (Hepes and Unesco). I have found no style manuals that would accept RuBisCO, RubisCO or any of the other capitalization schemes that are used. Because rubisco is so central to photosynthesis and better recognized than the words it stands for I believe it should be all lower case like “laser,” which is more easily understood than light amplification by stimulated emission of radiation. The use of Rubisco is tolerable, but other capitalization schemes should be abandoned. I will use rubisco here.


Download references


My research on the carbon metabolism of photosynthesis is supported by U.S. Department of Energy Grant DE-FG02-91ER2002. Partial salary support came from Michigan AgBioResearch. I thank Sean Weise for finding the original use of “rubisco”, Joe Berry for telling me about the fisherman in Fig. 6, and Christoph Benning for the loan of the lollipop from Ed Tolbert’s lab.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Thomas D. Sharkey.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary material 1 (PPTX 574 KB)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Sharkey, T.D. Discovery of the canonical Calvin–Benson cycle. Photosynth Res 140, 235–252 (2019).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Bassham
  • Benson
  • Calvin
  • Calvin–Benson cycle
  • 14CO2
  • Gluconeogenesis
  • Pentose phosphate pathway
  • Rubisco