Laisk measurements in the non-steady-state: tests in plants exposed to warming and variable CO2 concentrations
| Autor: | Stephanie C Schmiege, Thomas D Sharkey, Berkley Walker, Julia Hammer, Danielle A Way |
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| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Plant Physiology. |
| ISSN: | 1532-2548 0032-0889 |
| DOI: | 10.1093/plphys/kiad305 |
| Popis: | Light respiration (RL) is an important component of plant carbon balance and a key parameter in photosynthesis models. RL is often measured using the Laisk method, a gas exchange technique that is traditionally employed under steady-state conditions. However, a non-steady-state dynamic assimilation technique (DAT) may allow for more rapid Laisk measurements. In two studies, we examined the efficacy of DAT for estimating RL and the parameter Ci* (the intercellular CO2 concentration where rubisco’s oxygenation velocity is twice its carboxylation velocity), which is also derived from the Laisk technique. In the first study, we compared DAT and steady-state RL and Ci* estimates in paper birch (Betula papyrifera) growing under control and elevated temperature and CO2 concentrations. In the second, we compared DAT-estimated RL and Ci* in hybrid poplar (Populus nigra L. x P. maximowiczii A. Henry ‘NM6’) exposed to high or low CO2 concentration pre-treatments. The DAT and steady- state methods provided similar RL estimates in B. papyrifera, and we found little acclimation of RL to temperature or CO2; however, Ci* was higher when measured with DAT compared to steady-state methods. These Ci* differences were amplified by the high or low CO2 pre-treatments. We propose that changes in the export of glycine from photorespiration may explain these apparent differences in Ci*. |
| Databáze: | OpenAIRE |
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