Seasonal change in the balance between capacities of RuBP carboxylation and RuBP regeneration affects CO₂ response of photosynthesis in Polygonum cuspidatum

• Published in: Journal of experimental botany Vol. 56; no. 412; pp. 755 - 763
• Main Authors: Onoda, Yusuke, Hikosaka, Kouki, Hirose, Tadaki
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.02.2005; Oxford Publishing Limited (England)
• Subjects: age; Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agricultural and forest meteorology; Agronomy. Soil science and plant productions; air temperature; Allocation of photosynthetic proteins; Biological and medical sciences; carbon dioxide; Carbon Dioxide - pharmacology; Climatic adaptation. Acclimatization; cytochrome f; Cytochromes f - metabolism; electron transfer; Electron Transport; elevated atmospheric gases; enzyme activity; Fallopia japonica; Fallopia japonica - drug effects; Fallopia japonica - metabolism; Fallopia japonica - physiology; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Jmax; leaves; photosynthesis; Photosynthesis - drug effects; Photosynthesis - physiology; Plant Leaves - metabolism; ribulose-bisphosphate carboxylase; Ribulose-Bisphosphate Carboxylase - metabolism; Ribulosephosphates - metabolism; Rubisco; seasonal variation; seasonality; Seasons; senescence; stimulation of photosynthesis; temperature acclimation; Vcmax; Cytochrome; Climate; Senescence; Temperature; cytochrome f; stimulation of photosynthesis; Growth; Allocation of photosynthetic proteins; Carbon dioxide; Ribulose-bisphosphate carboxylase; Rubisco; Lyases; Carboxy-lyases; Dicotyledones; Angiospermae; Vcmax; Enzyme; Polygonaceae; Plant leaf; Regeneration; Carbon-carbon lyases; Polygonum; Jmax; Spermatophyta; temperature acclimation; Photosynthesis; seasonality
• ISSN: 0022-0957; 1460-2431; 1460-2431
• DOI: 10.1093/jxb/eri052

The balance between the capacities of RuBP (ribulose-1,5-bisphosphate) carboxylation (V[subscript cmax]) and RuBP regeneration (expressed as the maximum electron transport rate, J[subscript max]) determines the CO₂ dependence of the photosynthetic rate. As it has been suggested that this balance changes depending on the growth temperature, the hypothesis that the seasonal change in air temperature affects the balance and modulates the CO₂ response of photosynthesis was tested. V[subscript cmax] and J[subscript max] were determined in summer and autumn for young and old leaves of Polygonum cuspidatum grown at two CO₂ concentrations (370 and 700 [micro]mol mol⁻¹). Elevated CO₂ concentration tended to reduce both V[subscript cmax] and J[subscript max] without changing the J[subscript max]:V[subscript cmax] ratio. The seasonal environment, on the other hand, altered the ratio such that the J[subscript max]:V[subscript cmax] ratio was higher in autumn leaves than summer leaves. This alternation made the photosynthetic rate more dependent on CO₂ concentration in autumn. Therefore, when photosynthetic rates were compared at growth CO₂ concentration, the stimulation in photosynthetic rate was higher in young-autumn than in young-summer leaves. In old-autumn leaves, the stimulation of photosynthesis brought by a change in the J[subscript max]:V[subscript cmax] ratio was partly offset by accelerated leaf senescence under elevated CO₂. Across the two seasons and the two CO₂ concentrations, V[subscript cmax] was strongly correlated with Rubisco and J[subscript max] with cytochrome f content. These results suggest that seasonal change in climate affects the relative amounts of photosynthetic proteins, which in turn affect the CO₂ response of photosynthesis.