Crassulacean acid metabolism (CAM) in Kalancho�: Changes in intercellular CO2 concentration during a normal CAM cycle and during cycles in continuous light or darkness

Planta ◽  
1981 ◽  
Vol 152 (1) ◽  
pp. 87-92 ◽  
Author(s):  
M. Kluge ◽  
Ch. B�hlke ◽  
O. Queiroz
2003 ◽  
Vol 384 (5) ◽  
pp. 721-728 ◽  
Author(s):  
A. Bohn ◽  
S. Hinderlich ◽  
M.-T. Hütt ◽  
F. Kaiser ◽  
U. Lüttge

AbstractLeaves of the Crassulacean acid metabolism (CAM) plant Kalanchoë daigremontiana Hamet et Perrier de la Bâthie show overt circadian rhythms in net CO2 uptake, leaf conductance to water and intercellular CO2 concentration, which are entrained by periodic temperature cycles. To probe their sensitivity to thermoperiodic perturbations, intact leaves were exposed to continuous light intensity and temperature cycles with a period of 16 h, applying a set of different baseline temperatures and thermodriver amplitudes. All three overt rhythms were analyzed with respect to their frequency spectra and their phase relations with the thermodriver. For most stimulation protocols, stomatal conductance and net CO2 change were fully or partially entrained by the temperature pulses, while the internal CO2 concentration remained dominated by oscillations in the circadian range. Prolonged time series recorded for up to 22 d in continuous light underline the robustness of these circadian oscillations. This suggests that the overt circadian rhythm of net CO2 uptake in CAM results from the interaction of two coupled original systems: (i) an endogenous cycle of CO2 fixation in the mesophyll, showing very robust periodic activity, and (ii) stomatal movements that respond to environmental stimuli independently of rhythmic processes in the mesophyll, and thus modulate the gas exchange amplitude.


2019 ◽  
Vol 12 (1) ◽  
pp. 73
Author(s):  
Mokhtar Baraket ◽  
Sondes Fkiri ◽  
Ibtissam Taghouti ◽  
Salma Sai Kachout ◽  
Amel Ennajah ◽  
...  

In north Tunisia, the Quercus suber L. forests have shown a great decline indices as well as a non-natural regeneration. The climate changes could accentuate this unappreciated situation. In this study, the effect of water deficit on physiological behavior of Quercus suber seedlings was investigated. Photosynthetic responses of 15 months old Cork oak seedlings grown for 30 days under 40% and 80% soil water water content (control) were evaluated. Results showed a negative effect of water deficit and a positive effect of the intercellular CO2 concentration increase both on photosynthesis and transpiration. Stomata conductance might play a major role in balancing gas exchanges between the leaf and its environment. Moreover, global warming could negatively affect carbon uptake of Cork oak species in northern Tunisia. Elevated CO2 leaf content will benefit Cork oak growing under water deficit by decreasing both photoysnthesis and transpiration, which will decrease either the rate or the severity of water deficits, with limited effects on metabolism. the results suggest that high intercellular CO2 concentration could increase water use efficiency among Cork oak species.


2012 ◽  
Vol 39 (3) ◽  
pp. 199 ◽  
Author(s):  
Violeta Velikova ◽  
Tommaso La Mantia ◽  
Marco Lauteri ◽  
Marco Michelozzi ◽  
Isabel Nogues ◽  
...  

We investigated the consequences of recurrent winter flooding with saline water on a lemon (Citrus × limon (L.) Burm.f.) orchard, focussing on photosynthesis limitations and emission of secondary metabolites (isoprenoids) from leaves and fruits. Measurements were carried out immediately after flooding (December), at the end of winter (April) and after a dry summer in which plants were irrigated with optimal quality water (September). Photosynthesis was negatively affected by flooding. The effect was still visible at the end of winter, whereas the photosynthetic rate was fully recovered after summer, indicating an unexpected resilience capacity of flooded plants. Photosynthesis inhibition by flooding was not due to diffusive limitations to CO2 entry into the leaf, as indicated by measurements of stomatal conductance and intercellular CO2 concentration. Biochemical and photochemical limitations seemed to play a more important role in limiting the photosynthesis of flooded plants. In young leaves, characterised by high rates of mitochondrial respiration, respiratory rates were enhanced by flooding. Flooding transiently caused large and rapid emission of several volatile isoprenoids. Emission of limonene, the most abundant compound, was stimulated in the leaves, and in young and mature fruits. Flooding changed the blend of emitted isoprenoids, but only few changes were observed in the stored isoprenoids pool.


2020 ◽  
Vol 48 (3) ◽  
pp. 1637-1648
Author(s):  
Yujie YANG ◽  
Wenjie LI ◽  
Xinru HE ◽  
Die HU ◽  
Yongjun FEI

Experiments were conducted on 1-year Phoebe chekiangensis seedlings treated by different concentration (0, 300, 600, 900, 1200 mg/L) of Pb (NO3)2. Sixty days later, determination was implemented on seedling growth, physiological and photosynthetic parameters. The results showed that the lower concentration treated could promote the growth of the seedlings. But with the increase of concentration of lead, P. chekiangensis seedling height increment, ground diameter growth, whole biomass, total root surface area, root volume, total root length and root activity decreased, while root-shoot ratio present a rising trend. With the increase of concentration of Pb(NO3)2 solution, the membrane permeability and MDA content of P. chekiangensis seedlings showed a trend of rise after the first reduce; the protein content and chlorophyll content presented a trend of decrease after the first increase; while the POD, SOD and CAT activity increased firstly but decreased afterwards; the net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration rate were all increase at first then decrease, which indicated that protection enzyme activity and membrane was damaged thus the growth of P. chekiangensis seedlings was inhibited.


2006 ◽  
Vol 29 (4) ◽  
pp. 497-510 ◽  
Author(s):  
DAVID T. TISSUE ◽  
MARGARET M. BARBOUR ◽  
JOHN E. HUNT ◽  
MATTHEW H. TURNBULL ◽  
KEVIN L. GRIFFIN ◽  
...  

1994 ◽  
Vol 21 (4) ◽  
pp. 507 ◽  
Author(s):  
H Poorter ◽  
GD Farquhar

Various aspects of the water economy were investigated for a range of herbaceous species varying in relative growth rate. Plants were grown in a growth chamber with a non-limiting supply of water and nutrients, and the rate of transpiration, short-term intercellular CO2 concentration and long-term carbon isotope discrimination (Δ) in the leaves were determined. No correlation was found between the relative growth rate of these species, and the transpiration rate per unit leaf area, the intercellular CO2 concentration and the 13C-discrimination. There was a positive correlation, however, with the rate of water uptake per unit root weight. From these observations we infer that the previously observed differences in photosynthetic nitrogen-use efficiency, the rate of photosynthesis per unit leaf nitrogen, can not be explained by variation in intercellular CO2 concentration. These data were also used to analyse correlations between Δ and both growth parameters and chemical composition. Apart from parameters related to the water economy, Δ only correlated (positively) with the fractional biomass allocation to the roots (root weight ratio) and the specific root length (root length divided by root weight), and not with any other investigated growth parameters.


2016 ◽  
Vol 39 (11) ◽  
pp. 2404-2413 ◽  
Author(s):  
Russell K. Monson ◽  
Amberly A. Neice ◽  
Nicole A. Trahan ◽  
Ian Shiach ◽  
Joel T. McCorkel ◽  
...  

2015 ◽  
Vol 209 (4) ◽  
pp. 1600-1612 ◽  
Author(s):  
Jeff W. G. Kelly ◽  
Remko A. Duursma ◽  
Brian J. Atwell ◽  
David T. Tissue ◽  
Belinda E. Medlyn

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