Premium
The temperature response of C 3 and C 4 photosynthesis
Author(s) -
SAGE ROWAN F.,
KUBIEN DAVID S.
Publication year - 2007
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.1365-3040.2007.01682.x
Subject(s) - rubisco , photosynthesis , acclimatization , photosynthetic capacity , ribulose , botany , electron transport chain , pyruvate carboxylase , biology , horticulture , chemistry , biochemistry , enzyme
We review the current understanding of the temperature responses of C 3 and C 4 photosynthesis across thermal ranges that do not harm the photosynthetic apparatus. In C 3 species, photosynthesis is classically considered to be limited by the capacities of ribulose 1·5‐bisphosphate carboxylase/oxygenase (Rubisco), ribulose bisphosphate (RuBP) regeneration or P i regeneration. Using both theoretical and empirical evidence, we describe the temperature response of instantaneous net CO 2 assimilation rate ( A ) in terms of these limitations, and evaluate possible limitations on A at elevated temperatures arising from heat‐induced lability of Rubisco activase. In C 3 plants, Rubisco capacity is the predominant limitation on A across a wide range of temperatures at low CO 2 (<300 µ bar), while at elevated CO 2 , the limitation shifts to P i regeneration capacity at suboptimal temperatures, and either electron transport capacity or Rubisco activase capacity at supraoptimal temperatures. In C 4 plants, Rubisco capacity limits A below 20 °C in chilling‐tolerant species, but the control over A at elevated temperature remains uncertain. Acclimation of C 3 photosynthesis to suboptimal growth temperature is commonly associated with a disproportional enhancement of the P i regeneration capacity. Above the thermal optimum, acclimation of A to increasing growth temperature is associated with increased electron transport capacity and/or greater heat stability of Rubisco activase. In many C 4 species from warm habitats, acclimation to cooler growth conditions increases levels of Rubisco and C 4 cycle enzymes which then enhance A below the thermal optimum. By contrast, few C 4 species adapted to cooler habitats increase Rubisco content during acclimation to reduced growth temperature; as a result, A changes little at suboptimal temperatures. Global change is likely to cause a widespread shift in patterns of photosynthetic limitation in higher plants. Limitations in electron transport and Rubisco activase capacity should be more common in the warmer, high CO 2 conditions expected by the end of the century.