This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (40) Citing Articles via Google Scholar Google Scholar Articles by Rogers, S. M. D. Articles by Widholm, J. M. Search for Related Content PubMed PubMed Citation Articles by Rogers, S. M. D. Articles by Widholm, J. M. Agricola Articles by Rogers, S. M. D. Articles by Widholm, J. M.

Metabolism and Enzymology

Photosynthetic Characteristics of a Photoautotrophic Cell Suspension Culture of Soybean ¹

Department of Agronomy, University of Illinois, Urbana, Illinois 61801

A soybean suspension culture (SB-P) which can grow photoautotrophically in 5% CO₂ will not grow in ambient CO₂ levels. This elevated CO₂ requirement seems to be due to the additive effects of a number of factors. The in vivo activity of ribulose-1,5-bisphosphate carboxylase (RuBPcase) is much lower in the SB-P cells, compared to soybean plants. This may be due to the low light intensity used to culture the cells, which has been shown to decrease both the amount and activity in whole plants, resulting in a low rate of net photosynthesis. The RuBPcase activation level is also lowered in air CO₂ levels. The presence of the liquid medium raises the cells CO₂ compensation concentration (the CO₂ concentration reached when the rates of CO₂ fixed by photosynthesis and the CO₂ respired by the cells are equal). These factors, coupled with the high respiratory loss of CO₂ all contribute to reduced net photosynthesis in air, resulting in a photosynthetic capacity that is inadequate for cell survival. Active cell division, low photosynthetic capacity, elevated respiration, and a low ratio of RuBPcase(initial)/phosphoenolpyruvate carboxylase are traits that SB-P cells share with young leaf cells, indicating SB-P cell physiology may be comparable to that of young expanding leaves rather than to that of mature leaves.

This article has been cited by other articles:

				V. Andreu, R. Collados, P. S. Testillano, M. d. C. Risueno, R. Picorel, and M. Alfonso In Situ Molecular Identification of the Plastid {omega}3 Fatty Acid Desaturase FAD7 from Soybean: Evidence of Thylakoid Membrane Localization Plant Physiology, December 1, 2007; 145(4): 1336 - 1344. [Abstract] [Full Text] [PDF]