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Heterogeneity of leaf CO 2 assimilation during photosynthetic induction
Author(s) -
BRO E.,
MEYER S.,
GENTY B.
Publication year - 1996
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.1365-3040.1996.tb00013.x
Subject(s) - photosynthesis , chlorophyll fluorescence , electron transport chain , assimilation (phonology) , irradiance , carbon assimilation , chemistry , botany , biophysics , biology , physics , optics , linguistics , philosophy
Spatial mid temporal variations in the distribution of photosynthesis over the leaf area were investigated during induction upon illumination of Rosa rubiginosa L. leaves. Gas exchange and maps of relative photosynthetie electron transport activity computed from chlorophyll fluorescence images were simultaneously monitored. In air, after 15 h of dark adaptation, linear electron transport was heterogeneously distributed over the leaf area during the induction. This patchy induction was explained by asynchronous metabolism activation for the first 10 min of illumination, concomitant asynchronous limitation by intrinsic metabolism and stomatal apertures (10–30 min) and finally by only stomatal limitation beyond 30 min. A brief transition to non‐photorespiratory conditions after 20 min of illumination under subsaturating irradiance revealed a marked heterogeneity of CO 2 assimilation, presumably as a result of heterogeneous stomatal apertures. The frequency distribution of CO 2 assimilation was unimodal. During the induction, heterogeneity gradually decreased and photosynthesis was uniform at steady‐state. After 10 min of dark adaptation, heterogeneity of linear electron transport activity occurred during the first 15 min of a second induction and mainly resulted from metabolic limitation.