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Responses of respiration in the light to warming in field‐grown trees: a comparison of the thermal sensitivity of the Kok and Laisk methods
Author(s) -
Way Danielle A.,
Aspinwall Michael J.,
Drake John E.,
Crous Kristine Y.,
Campany Courtney E.,
Ghannoum Oula,
Tissue David T.,
Tjoelker Mark G.
Publication year - 2019
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.15566
Subject(s) - respiration , phosphoenolpyruvate carboxylase , degree (music) , chemistry , botany , biology , horticulture , zoology , photosynthesis , physics , acoustics
Summary The Kok and Laisk techniques can both be used to estimate light respiration R light . We investigated whether responses of R light to short‐ and long‐term changes in leaf temperature depend on the technique used to estimate R light . We grew Eucalyptus tereticornis in whole‐tree chambers under ambient temperature (AT) or AT + 3°C (elevated temperature, ET). We assessed dark respiration R dark and light respiration with the Kok ( R Kok ) and Laisk ( R Laisk ) methods at four temperatures to determine the degree of light suppression of respiration using both methods in AT and ET trees. The ET treatment had little impact on R dark , R Kok or R Laisk . Although the thermal sensitivities of R Kok or R Laisk were similar, R Kok was higher than R Laisk . We found negative values of R Laisk at the lowest measurement temperatures, indicating positive net CO 2 uptake, which we propose may be related to phosphoenolpyruvate carboxylase activity. Light suppression of R dark decreased with increasing leaf temperature, but the degree of suppression depended on the method used. The Kok and Laisk methods do not generate the same estimates of R light or light suppression of R dark between 20 and 35°C. Negative rates of R Laisk imply that this method may become less reliable at low temperatures.