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Feedback limitation of photosynthesis of Phaseolus vulgaris L grown in elevated CO 2
Author(s) -
SOCIAS F. X.,
MEDRANO H.,
SHARKEY T. D.
Publication year - 1993
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.1993.tb00847.x
Subject(s) - phaseolus , photosynthesis , ribulose , sucrose , rubisco , acclimatization , partial pressure , botany , sucrose phosphate synthase , horticulture , carbon dioxide , chemistry , biology , oxygen , food science , sucrose synthase , invertase , organic chemistry
The capacity for photosynthesis is often affected when plants are grown in air with elevated CO 2 partial pressure. We grew Phaseolus vulgaris L. in 35 and 65 Pa CO 2 and measured photosynthetic parameters. When assayed at the growth CO 2 level, photosynthesis was equal in the two CO 2 treatments. The maximum rate of ribulose‐1,5‐bisphosphate (RuBP) consumption was lower in plants grown at 65 Pa, but the CO 2 partial pressure at which the maximum occurred was higher in the high‐CO 2 ‐grown plants, indicating acclimation to high CO 2 . The acclimation of RuBP consumption to CO 2 involved a reduction of the activity of RuBP carboxylase which resulted from reduced carbamylation, not a loss of protein. The rate of RuBP consumption declined with CO 2 when the CO 2 partial pressure was above 50Pa in plants grown under both CO 2 levels. This was caused by feedback inhibition as judged by a lack of response to removing O 2 from the air stream. The rate of photosynthesis at high CO 2 was lower in the high‐CO 2 ‐grown plants and this was correlated with reduced activity of sucrose‐phosphate synthase. This is only the second report of O 2 ‐insensitive photosynthesis under growth conditions for plants grown in high CO 2 .