Quantum yields of photosynthesis at temperatures between −;2°C and 35°C in a cold-tolerant C3 plant (Pinus sylvestris) during the course of one year
Article first published online: 28 APR 2006
Plant, Cell & Environment
Volume 10, Issue 4, pages 287–295, June 1987
How to Cite
LEVERENZ, J. W. and ÖQUIST, G. (1987), Quantum yields of photosynthesis at temperatures between −;2°C and 35°C in a cold-tolerant C3 plant (Pinus sylvestris) during the course of one year. Plant, Cell & Environment, 10: 287–295. doi: 10.1111/j.1365-3040.1987.tb01608.x
- Issue published online: 28 APR 2006
- Article first published online: 28 APR 2006
- Received 10 September 1986; accepted for publication 1 December 1986
- Pinus sylrestris;
- Scots pine;
- quantum yield;
- carbon dioxide;
Abstract Quantum yields of photosynthetic CO2 uptake by Pinus sylvestris (L.) shoots were measured at temperatures between −; 2°C and 35°C from September 1984 to September 1985. The ratio of variable to peak fluorescence of photosystem II (Fv/Fp) was also measured. Quantum yield measured at 25°C varied with time from a low winter value of 0.017 to a high summer value of 0.057. This variation was strongly correlated to variation in FvFp(r2= 0.91).
The response of quantum yield to temperature changed with season. During winter, quantum yield was essentially constant between 0°C and 35°C. The constancy above 5°C was associated with a strong increase in intercellular space CO2 (Ci) with temperature. In June, the quantum yield peaked at 5°C, decreased sharply below 5°C, and was rather constant between 25°C and 35°C. This insensitivity to increased temperature above 25°C was attributed to a large increase in Ci In contrast, by September, the quantum yield was less sensitive to temperature below 5°C and more sensitive above 25°C, despite an unchanged Ci response with increasing temperatures as compared with June. In August, quantum yields were lowered at 0, 5 and 15°C, apparently as a result of high carbohydrate levels in the leaves. Overall, the results suggest that there are sites other than in photosystem II or at ribulose bisphosphate carboxylase/oxygenase at which the quantum yield of photosynthetic CO2 uptake is affected. Possible causes for the changes in efficiency are discussed.