Quantum Yields for CO2 Uptake in C3 and C4 Plants: Dependence on Temperature, CO2, and O2 Concentration 1
AUTOR(ES)
Ehleringer, James
RESUMO
The quantum yields of C3 and C4 plants from a number of genera and families as well as from ecologically diverse habitats were measured in normal air of 21% O2 and in 2% O2. At 30 C, the quantum yields of C3 plants averaged 0.0524 ± 0.0014 mol CO2/absorbed einstein and 0.0733 ± 0.0008 mol CO2/absorbed einstein under 21 and 2% O2. At 30 C, the quantum yields of C4 plants averaged 0.0534 ± 0.0009 mol CO2/absorbed einstein and 0.0538 ± 0.0011 mol CO2/absorbed einstein under 21 and 2% O2. At 21% O2, the quantum yield of a C3 plant is shown to be strongly dependent on both the intercellular CO2 concentration and leaf temperature. The quantum yield of a C4 plant, which is independent of the intercellular CO2 concentration, is shown to be independent of leaf temperature over the ranges measured. The changes in the quantum yields of C3 plants are due to changes in the O2 inhibition. The evolutionary significance of the CO2 dependence of the quantum yield in C3 plants and the ecological significance of the temperature effects on the quantum yields of C3 and C4 plants are discussed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=542335Documentos Relacionados
- Temperature Dependence of the Linkage of Quantum Yield of Photosystem II to CO2 Fixation in C4 and C3 Plants.
- Effects of O2 Tension and Temperature during Light Uptake of 14CO2 on the Dark Release of 14CO2 by Excised C3 and C4 Leaves 1
- Regulation of Photosynthesis in C3 and C4 Plants: A Molecular Approach.
- Anapleurotic CO2 Fixation by Phosphoenolpyruvate Carboxylase in C3 Plants 1
- The Effect of Temperature on the Occurrence of O2 and CO2 Insensitive Photosynthesis in Field Grown Plants 1