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Independent circadian regulation of assimilation and stomatal conductance in the ztl‐1 mutant of Arabidopsis
Author(s) -
Dodd Antony N.,
Parkinson Keith,
Webb Alex A. R.
Publication year - 2004
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/j.1469-8137.2004.01005.x
Subject(s) - stomatal conductance , cuvette , circadian rhythm , arabidopsis , circadian clock , biology , photosynthesis , arabidopsis thaliana , mutant , botany , biophysics , chemistry , genetics , physics , optics , gene , neuroscience
Summary• We have developed a low‐cost, multicuvette infrared gas analyser system for medium‐term measurement of gas exchange in Arabidopsis thaliana plants. The system enables parallel measurement of stomatal conductance and CO 2 assimilation, providing direct comparison between genotypes. This allows the molecular genetic tools that are available in Arabidopsis to be combined with the power of whole‐plant physiology. • The system was designed specifically for quantification of circadian rhythms of gas exchange, and controls cuvette relative humidity and CO 2 concentration under both continuous light and light–dark cycles. Cuvette humidity is controlled by a unique feedback system that prevents humidity oscillations within the cuvettes. • Using this new system we demonstrated that, under continuous light, there was a longer circadian period for both stomatal conductance and CO 2 fixation in the zeitlupe ( ztl‐1 ) mutant compared to wild type. • Wild‐type ZTL expression is therefore required for normal cycles of CO 2 fixation and stomatal conductance. Furthermore, we demonstrate that different circadian periods can coexist in a single plant, highlighting the cell autonomous nature of the plant circadian oscillator.