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Long‐term effects of elevated CO 2 and nutrients on photosynthesis and rubisco in loblolly pine seedlings
Author(s) -
TISSUE D. T.,
THOMAS R. B.,
STRAIN B. R.
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.tb00508.x
Subject(s) - rubisco , photosynthesis , nutrient , loblolly pine , acclimatization , botany , chlorophyll , horticulture , chemistry , agronomy , pinus <genus> , biology , zoology , ecology
The effects of long‐term CO 2 enhancement and varying nutrient availability on photosynthesis and ribulose‐1,5‐bisphosphate carboxylase/oxygenase (rubisco) were studied on loblolly pine ( Pinus taeda L.) seedlings grown in two atmospheric CO 2 partial pressures (35 and 65 Pa) and three nutrient treatments (low N, low P, and high N and P). Measurements taken in late autumn (November) after 2 years of CO 2 enrichment and nutrient addition showed that photosynthetic rates were higher for plants grown at elevated CO 2 only when they received supplemental N. Total rubisco activity and rubisco content decreased at elevated CO 2 , but there was an increase in activation state. At elevated CO 2 , proportionately less N was found in rubisco and more N was found in the light reaction components. These results demonstrate acclimation of photosynthetic processes to elevated CO 2 through reallocation of N. Loblolly pine grown in nutrient conditions similar to native soils (low N availability) had lower needle N and chlorophyll content, lower total rubisco activity and content, and lower photosynthetic rates than plants grown at high N and P. This suggests that the magnitude of the photosynthetic response to a future, high‐CO 2 environment will be dependent on soil fertility in the system.