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Growth in elevated CO 2 protects photosynthesis against high‐temperature damage
Author(s) -
Taub Daniel R.,
Seemann Jeffrey R.,
Coleman James S.
Publication year - 2000
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 - 10.1046/j.1365-3040.2000.00574.x
Subject(s) - cucumis , photosynthesis , carbon dioxide , herbaceous plant , horticulture , botany , biology , chemistry , ecology
We present evidence that plant growth at elevated atmospheric CO 2 increases the high‐temperature tolerance of photosynthesis in a wide variety of plant species under both greenhouse and field conditions. We grew plants at ambient CO 2 (~ 360 μ mol mol − 1 ) and elevated CO 2 (550–1000 μ mol mol − 1 ) in three separate growth facilities, including the Nevada Desert Free‐Air Carbon Dioxide Enrichment (FACE) facility. Excised leaves from both the ambient and elevated CO 2 treatments were exposed to temperatures ranging from 28 to 48 °C. In more than half the species examined (4 of 7, 3 of 5, and 3 of 5 species in the three facilities), leaves from elevated CO 2 ‐grown plants maintained PSII efficiency ( F v / F m ) to significantly higher temperatures than ambient‐grown leaves. This enhanced PSII thermotolerance was found in both woody and herbaceous species and in both monocots and dicots. Detailed experiments conducted with Cucumis sativus showed that the greater F v / F m in elevated versus ambient CO 2 ‐grown leaves following heat stress was due to both a higher F m and a lower F o , and that F v / F m differences between elevated and ambient CO 2 ‐grown leaves persisted for at least 20 h following heat shock. Cucumis sativus leaves from elevated CO 2 ‐grown plants had a critical temperature for the rapid rise in F o that averaged 2·9 °C higher than leaves from ambient CO 2 ‐grown plants, and maintained a higher maximal rate of net CO 2 assimilation following heat shock. Given that photosynthesis is considered to be the physiological process most sensitive to high‐temperature damage and that rising atmospheric CO 2 content will drive temperature increases in many already stressful environments, this CO 2 ‐induced increase in plant high‐temperature tolerance may have a substantial impact on both the productivity and distribution of many plant species in the 21st century.