No evidence for triose phosphate limitation of light-saturated leaf photosynthesis under current atmospheric CO2 concentration

The triose phosphate utilization rate (TPU) has been identified as is one of the processes that can limit terrestrial plant photosynthesis. However, we lack a robust quantitative assessment of TPU limitation of photosynthesis at the global scale. As a result, TPU, and its potential limitation of pho...

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Bibliographic Details
Published in:Plant, Cell & Environment
Main Authors: Kumarathunge, Dushan (S32842), Medlyn, Belinda E. (R18040), Drake, John E. (R17039), Rogers, Alistair, Tjoelker, Mark G. (R16688)
Other Authors: Hawkesbury Institute for the Environment (Host institution)
Format: Article in Journal/Newspaper
Language:English
Published: U.K., Wiley-Blackwell Publishing 2019
Subjects:
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photosynthesis
biosphere
temperature
electron transport
triose phosphate
atmospheric carbon dioxide
Arctic
Tundra
Online Access:https://doi.org/10.1111/pce.13639
http://hdl.handle.net/1959.7/uws:52509
Description
Summary:The triose phosphate utilization rate (TPU) has been identified as is one of the processes that can limit terrestrial plant photosynthesis. However, we lack a robust quantitative assessment of TPU limitation of photosynthesis at the global scale. As a result, TPU, and its potential limitation of photosynthesis, is poorly represented in terrestrial biosphere models (TBMs). In this study, we utilised a global dataset of photosynthetic CO2 response curves representing 141 species from tropical rainforests to Arctic tundra. We quantified TPU by fitting the standard biochemical model of C3 photosynthesis to measured photosynthetic CO2 response curves, and characterised its instantaneous temperature response. Our results demonstrate that TPU does not limit leaf photosynthesis at the current ambient atmospheric CO2 concentration. Furthermore, our results showed that the light saturated photosynthetic rates of plants growing in cold environments are not more often limited by TPU than those of plants growing in warmer environments. In addition, our study showed that the instantaneous temperature response of TPU is distinct from temperature response of the maximum rate of Rubisco carboxylation. The new formulations of the temperature response of TPU derived in this study may prove useful in quantifying the biochemical limits to terrestrial plant photosynthesis and improve the representation of plant photosynthesis in TBMs.

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