TY - JOUR
T1 - Photoacoustic signal generation in leaves
T2 - are O2-consuming processes involved?
AU - Charland, Marc
AU - Veeranjaneyulu, Konka
AU - Charlebois, Denis
AU - Leblanc, Roger M.
N1 - Funding Information:
The authors gratefully acknowledge the Natural Sciences and Engineering Research Council of Canada (NSERC) and Fonds pour la Formation de Chercheurs et l'Aide ?~ la Recherche (FCAR) for grants provided to R.M.L.M.C. also thanks NSERC and i'Universit6 du QuEbec ?~ Trois-Rivi~res (Intervention spEciale) for graduate fellowships.
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1992/1/16
Y1 - 1992/1/16
N2 - The photoacoustic signal from a green leaf is the vectorial sum of photothermal (heat emitted by non-radiative deexcitation of molecules) and photobaric (photosynthetic O2 exchanges) contributions. With sugar maple leaf, we have observed a decline of the O2 signal in the course of time, once the leaf attained a steady-state photosynthesis. This decline of the O2 signal was not due to a decrease in photochemical activity as was evident by a stable fluorescence signal and constant energy storage. The rate and the extent of decline were larger at low modulation frequency and low modulated light intensity. The decline continued even in the presence of background far-red light (λ>715 nm). The above observations lead us to conclude that the photoacoustic O2 signal from leaves is influenced by O2-consuming processes. Data are discussed in relation to a possible occurrence of an equilibrium between oxygen-evolving and oxygen-consuming processes to account for the O2 signal in the plant cell. Moreover, the oxygen-uptake component may have to be included in the vectorial model of photoacoustic signal generation in leaves.
AB - The photoacoustic signal from a green leaf is the vectorial sum of photothermal (heat emitted by non-radiative deexcitation of molecules) and photobaric (photosynthetic O2 exchanges) contributions. With sugar maple leaf, we have observed a decline of the O2 signal in the course of time, once the leaf attained a steady-state photosynthesis. This decline of the O2 signal was not due to a decrease in photochemical activity as was evident by a stable fluorescence signal and constant energy storage. The rate and the extent of decline were larger at low modulation frequency and low modulated light intensity. The decline continued even in the presence of background far-red light (λ>715 nm). The above observations lead us to conclude that the photoacoustic O2 signal from leaves is influenced by O2-consuming processes. Data are discussed in relation to a possible occurrence of an equilibrium between oxygen-evolving and oxygen-consuming processes to account for the O2 signal in the plant cell. Moreover, the oxygen-uptake component may have to be included in the vectorial model of photoacoustic signal generation in leaves.
KW - (Sugar maple)
KW - Oxygen evolution
KW - Oxygen uptake process
KW - Photoacoustic spectroscopy
KW - Photosynthesis
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U2 - 10.1016/S0005-2728(05)80345-7
DO - 10.1016/S0005-2728(05)80345-7
M3 - Article
AN - SCOPUS:0026542991
VL - 1098
SP - 261
EP - 265
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
SN - 0005-2728
IS - 2
ER -