Distinctive diel growth cycles in leaves and cladodes of CAM plants: differences from C3 plants and putative interactions with substrate availability, turgor and cytoplasmic pH

2005 ◽  
Vol 32 (5) ◽  
pp. 421 ◽  
Author(s):  
Liezel M. Gouws ◽  
C. Barry Osmond ◽  
Ulrich Schurr ◽  
Achim Walter
Keyword(s):  
Malic Acid ◽  
Growth Dynamics ◽  
Maximum Growth ◽  
Co2 Assimilation ◽  
Growth Patterns ◽  
Phase Iii ◽  
C3 Plants ◽  
Cytoplasmic Ph ◽  
Cam Plants ◽  
Cell Turgor

Distinct diel rhythms of leaf and cladode expansion growth were obtained in crassulacean acid metabolism (CAM) plants under water-limited conditions, with maxima at mid-day during phase III of CO2 assimilation. This pattern coincided with the availability of CO2 for photosynthesis and growth during the decarboxylation of malic acid, with maximum cell turgor due to the nocturnally accumulated malic acid, and with the period of low cytoplasmic pH associated with malic acid movement from vacuole to cytosol. Maximum growth rates were generally only 20% of those in C3 plants and were reached at a different time of the day compared with C3 plants. The results suggest that malic acid, as a source of carbohydrates, and a determinant of turgor and cytoplasmic pH, plays a major role in the control of diel growth dynamics in CAM plants under desert conditions. The observed plasticity in phasing of growth rhythms under situations of differing water availability suggests that a complex network of factors controls the diel growth patterns in CAM plants and needs to be investigated further.

A comparison of CO2 and O2 exchange patterns and the relationship with chlorophyll fluorescence during photosynthesis in C3 and CAM plants

1998 ◽  
Vol 25 (1) ◽  
pp. 45 ◽  
Author(s):  
Kate Maxwell ◽  
Murray R. Badger ◽  
C. Barry Osmond
Keyword(s):  
Chlorophyll Fluorescence ◽  
Tca Cycle ◽  
Co2 Assimilation ◽  
Phase Iii ◽  
O2 Evolution ◽  
Co2 Uptake ◽  
Cam Plants ◽  
Co2 Diffusion ◽  
Oxygenase Activity ◽  
C3 Species

Patterns of CO2 and O2 exchange coupled to chlorophyll fluorescence were examined in the CAM plants Kalanchoe daigremontiana Hamet et Perr. and Hoya carnosa (L.f.) R.Br., and compared with the C3 species Sonchus oleraceus L. Patterns of CO2 assimilation during phase IV of CAM were as predicted for Rubisco-mediated atmospheric CO2 uptake in both CAM plants. The high energetic demand during decarboxylation (phase III) was reflected in a high, CO2-insensitive rate of gross O2 evolution. Uptake of external CO2 was significant during phase III and was not saturated at 1.5% CO2. Gross oxygen uptake in the light was CO2 sensitive in H. carnosa during phases III and IV, which suggests Rubisco oxygenase activity. Oxygen consumption comprised around 33% linear electron transport in K. daigremontiana during phase III (7.5 µmol O2 m-2 s-1 at saturating CO2), but we cannot yet distinguish whether this involves the Mehler reaction or TCA cycle and oxidative phosphorylation during deacidification. CO2 assimilation was saturated at 0.2% CO2 when the epidermis was removed in K. daigremontiana, suggesting a large stomatal and mesophyll resistance to CO2 diffusion. A linear relationship was obtained between the quantum yield of gross O2 evolution and the quantum efficiency of PSII.

scholarly journals Daily otolith growth and ontogenetic geochemical signatures of age-0 anchovy (Engraulis encrasicolus) in the Gulf of Cádiz (SW Spain).

2014 ◽  
Vol 15 (4) ◽  
pp. 781 ◽  
Author(s):  
I. A. CATALÁN ◽  
S. PÉREZ-MAYOL ◽  
I. ÁLVAREZ ◽  
J. RUIZ ◽  
M. PALMER ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Growth Dynamics ◽  
Maximum Growth ◽  
Growth Patterns ◽  
Estuarine System ◽  
Gulf Of Cadiz ◽  
Otolith Growth ◽  
Daily Growth ◽  
Average Growth ◽  
Gulf Of Cádiz

The European anchovy fishery in the Gulf of Cádiz (ICES Division IXa South) is largely influenced by age-0 individuals. Knowledge of young of the year growth dynamics is crucial for management, yet data on daily growth are lacking in the area. Linking growth patterns to the environment requires information on habitat occupancy through ontogeny of the fish that reach the fishery, as anchovy use different areas of the Gulf and the Guadalquivir Estuary through development. We describe the growth dynamics of age-0 anchovy through otolith microstructure analysis, and couple these data with data on microchemical signals in the otoliths to shed light into habitat use and growth dynamics in the area. Age-0 anchovy captured in September, 2011 in the Gulf ranged from 3 to 6 months old for similar sizes, with average growth rates varying twofold. Individual non-linear growth curves showed that maximum otolith growth was positively correlated with the date of spawning, which in turn was negatively correlated with the time to reach maximum growth. There was no correlation between growth parameters and body length or condition (Fulton K) at capture. The strontium:calcium (Sr/Ca) and magnesium:calcium (Mg/Ca) ratios were significantly lower at the edge of the otolith (approximately the age of capture) than at ages corresponding to larval and early juveniles (<60 days old), but values fell within typical estuarine-dwelling species. The barium:calcium ratio (Ba/Ca) increased significantly in the edge of the otolith, which possibly resulted from residency in highly productive coastal waters or from ontogenetic effects. The variance in otolith elemental ratios was larger at otolith back-calculated ages around 50 days old, age which coincides with the presumed closer dependence of estuarine waters. Our data are a first step towards understanding the contribution of the estuarine system to the fishery of anchovy in the Gulf. The limitations of the approach and future steps are discussed.

Crassulacean Acid Metabolism and Diurnal Variations of Internal CO2 and O2 Concentrations in Sedum praealtum DC

1979 ◽  
Vol 6 (4) ◽  
pp. 557 ◽  
Author(s):  
MH Spalding ◽  
DK Stumpf ◽  
MSB Ku ◽  
RH Burris ◽  
GE Edwards
Keyword(s):  
Malic Acid ◽  
Crassulacean Acid Metabolism ◽  
Acid Metabolism ◽  
Dark Period ◽  
Stomatal Closure ◽  
Co2 Concentration ◽  
Co2 Exchange ◽  
C3 Plants ◽  
Cam Plants ◽  
Internal Co2

Internal CO2 and O2 concentrations in Sedum praealtum DC. were determined by gas chromatography of 200-�l gas samples. Day-night monitoring showed that internal CO2 varied from a high of approximately 4000 �l/l during periods of daytime stomatal closure to a low of 270-280 �l/l during the dark period (stomata open). Internal O2 concentrations varied from a high of approximately 26 % at midday to a low of 20.8 % during the dark period. The calculated internal O2/CO2 ratio varied about 12-15-fold from 50-60 near midday to approximately 750 during the dark period (ratio in normal air is roughly 600). Day-night patterns of CO2 exchange and malic acid concentration were typical for a plant with crassulacean acid metabolism (CAM). Influx of CO2 during the late light period was inhibited by O2, but dark CO2 influx was O2-insensitive. Gas samples taken near midday from several CAM plants all showed elevated internal CO2 and O2 concentrations. Ratios of O2/CO2 in these plants ranged from 81 in Sedum praealtum to 285 in Hoya carnosa. The highest internal O2 concentration observed was 41.5% in Kalanchoe gastonis-bonnieri. The high CO2 concentration in leaves of CAM plants during daytime stomatal closure should provide a near- saturating level of this substrate for photosynthesis. In comparison to C3 plants, the relatively low O2/CO2 ratio in the CAM leaf during malic acid decarboxylation should be favourable for photosynthesis and unfavourable for O2 inhibition of photosynthesis.

Growth Increments and Geochemical Variations in the Molluscan Shell

1985 ◽  
Vol 13 ◽  
pp. 72-87 ◽  
Author(s):  
Douglas S. Jones
Keyword(s):  
Shell Growth ◽  
Maximum Growth ◽  
Growth Increment ◽  
Growth Patterns ◽  
Random Disturbance ◽  
Growth Increments ◽  
Molluscan Shell ◽  
External Shell ◽  
Periodic Growth ◽  
Geochemical Variations

Perhaps the one structural feature of the molluscan shell which has historically attracted the most attention from biologists and paleobiologists alike is the banding or growth increment variation associated with so many molluscan species. Such growth patterns are often prominently displayed on the external surfaces of shells and have long been the focus of serious biological and paleontological research (see reviews by Clark, 1974; Lutz and Rhoads, 1980). The usefulness of external shell growth patterns in ecological or paleoecological contexts is limited, however, by both the inability to distinguish true periodic features from random disturbance marks and by the extreme crowding of growth lines near the margins of mature shells. In the last two decades these problems have been surmounted with the recognition of periodic growth patterns within molluscan shells. Internal shell growth patterns are known from all classes of mollusks, but those in the Bivalvia have been studied most extensively. This is a result of the relative ease with which a complete ontogenetic growth record can be obtained by sectioning a shell along the axis of maximum growth (Rhoads and Pannella, 1970). Analogous ontogenetic records are very difficult, if not impossible, to obtain from coiled or spiral shells (e.g., gastropods) using current techniques (Lutz and Rhoads, 1980). This chapter, then, aims to review the major types of internal shell growth patterns described within molluscan shells (mainly bivalves) and to discuss their origin and applications in ecology and paleoecology. Also taken up in this chapter is a brief consideration of geochemical variations (stable oxygen and carbon isotopes and trace and minor elements) within molluscan shells. Physical-chemical, environmental, and physiological influences on shell chemistry are discussed in relation to how biogeochemical variations in the shell may be used to reconstruct paleoenvironmental conditions.

Resistance is useful: diurnal patterns of photosynthesis in C3 and crassulacean acid metabolism epiphytic bromeliads

2002 ◽  
Vol 29 (6) ◽  
pp. 679 ◽  
Author(s):  
Kate Maxwell
Keyword(s):  
Crassulacean Acid Metabolism ◽  
Acid Metabolism ◽  
Photosynthetic Electron Transport ◽  
Co2 Assimilation ◽  
Enzyme Activation ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Cam Plants ◽  
Diurnal Patterns ◽  
Rubisco Activation

This paper originates from a presentation at the IIIrd International Congress on Crassulacean Acid Metabolism, Cape Tribulation, Queensland, Australia, August 2001 Diurnal patterns of photosynthesis in response to environmental variables were investigated in an obligate C3 and a facultative C3-crassulacean acid metabolism (CAM) bromeliad species. A midday depression of photosynthesis occurred in both C3 groups, mediated as a decrease in stomatal conductance in response to increased vapour pressure difference. The response was associated with a reduction in Rubisco activation state during the period of maximum photon flux density. In contrast, the switch to CAM resulted in a strong shift in the pattern of Rubisco carbamylation, with full enzyme activation delayed until the midday period. For the first time it is demonstrated that the pattern of Rubisco activation differs between C3 and CAM plants of the same species under identical conditions. Despite large differences in Rubisco content between C3 and CAM plants, neither the amount of Rubisco or enzyme activity is thought to be limiting for photosynthesis, and it is suggested that Rubisco may function as a nitrogen store. Extreme CO2 diffusion limitation resulted in low rates of atmospheric CO2 assimilation that were associated with high rates of photosynthetic electron transport, and it is likely that photorespiration constitutes a significant electron sink over the entire diurnal course. Leaf morphological and physiological adaptations to drought stress are necessary for the epiphytic lifestyle but limit CO2 assimilation and confound the likelihood of high productivity.

scholarly journals Developmental growth patterns of the filter-feeder pterosaur, Pterodaustro guiñazui

2008 ◽  
Vol 4 (3) ◽  
pp. 282-285 ◽  
Author(s):  
A Chinsamy ◽  
L Codorniú ◽  
L Chiappe
Keyword(s):  
Growth Dynamics ◽  
Growth Patterns ◽  
Growth Strategy ◽  
Filter Feeder ◽  
Definitive Evidence ◽  
Developmental Growth ◽  
Adult Body ◽  
Body Sizes ◽  
Determinate Growth ◽  
Insight Into

Life-history parameters of pterosaurs such as growth and ontogenetic development represent an enigma. This aspect of pterosaur biology has remained perplexing because few pterosaur taxa are represented by complete ontogenetic series. Of these, Pterodaustro is unique in that besides being represented by hundreds of individuals with wing spans ranging from 0.3 to 2.5 m, it includes an embryo within an egg. Here we present a comprehensive osteohistological assessment of multiple skeletal elements of a range of ontogenetic sizes of Pterodaustro , and we provide unparalleled insight into its growth dynamics. We show that, upon hatching, Pterodaustro juveniles grew rapidly for approximately 2 years until they reached approximately 53% of their mature body size, whereupon they attained sexual maturity. Thereafter, growth continued for at least another 3–4 years at comparatively slower rates until larger adult body sizes were attained. Our analysis further provides definitive evidence that Pterodaustro had a determinate growth strategy.

Voxel based analysis of recurrence dynamics in intracranial aneurysms after coiling

2017 ◽  
Vol 10 (6) ◽  
pp. 571-576 ◽  
Author(s):  
Marielle Ernst ◽  
Anika Buchholz ◽  
Romain Bourcier ◽  
Hubert Desal ◽  
Pierre-Yves Le Floch ◽  
...  
Keyword(s):  
Observation Interval ◽  
Three Dimensional ◽  
Growth Dynamics ◽  
Volumetric Analysis ◽  
Growth Patterns ◽  
Steady Increase ◽  
Residual Flow ◽  
Tof Mra ◽  
Incomplete Occlusion

BackgroundUnderstanding aneurysm growth is critical for the appropriate follow-up of patients after coil embolization and the need for retreatment. The purpose of the study was to stratify the growth dynamics of aneurysm recurrences after coiling by volumetric analysis and to determine predictive factors for aneurysm recurrences.MethodsSource images of follow-up three-dimensional time of flight MR angiography (ToF-MRA) scans were compared with the first post-interventional ToF-MRA scan and analyzed for residual flow after co-registration using ANALYZE-software. In the event of incomplete occlusion, the residual volume was segmented and calculated. Growth dynamic was determined for each aneurysm after embolization.ResultsWe analyzed 326 patients with 345 aneurysms from two centers. Each case had at least two ToF-MRA examinations after endovascular therapy. The mean observation interval was 59 months. Volumetric analysis of 1139 follow-up MRAs revealed that 218/345 aneurysms (63.2%) showed complete occlusion on initial follow-up imaging, and of these 95.0% remained stable. A steady increase in intra-aneurysmal flow was observed in 83/345 (24.1%). Less frequent observations were a steep increase (21/345; 6.1%) and a decrease (27/345; 7.8%). Independent predictors of increasing residual flow were greatest aneurysm diameter, total coil length, and incomplete occlusion.ConclusionsVolumetric analysis of registered three-dimensional ToF-MRA follow-up datasets allows the detection of different growth patterns with high precision, avoids the low inter-rater reliability, and represents a promising approach for future studies that include analysis of more complex predictors of residual flow. In cases of aneurysm recurrence after coiling, the major pattern seems to be a steady increase in intra-aneurysmal flow over several months.

Carbon Dioxide Assimilation by Pineapple Plants, Ananas comosus (L.) Merr. II. Effects of Variation of the Day/Night Temperature Regime

1980 ◽  
Vol 7 (4) ◽  
pp. 375 ◽  
Author(s):  
TF Neales ◽  
PJM Sale ◽  
CP Meyer
Keyword(s):  
Temperature Regime ◽  
Co2 Assimilation ◽  
Leaf Conductance ◽  
Ananas Comosus ◽  
Co2 Efflux ◽  
Night Temperature ◽  
Cam Plants ◽  
Ambient Temperatures ◽  
Single Leaf ◽  
Enclosure Methods

The effects of variation of day/night temperature regime on the diurnal patterns of CO2 assimilation of pineapple plants were examined using single leaf and field enclosure methods. At day temperatures of 30°C, increasing night temperatures from 20 to 35°C reduced the total assimilation of CO2 per daily light/dark cycle from 6.5 to 1.3 g CO2 m-2 (leaf area) day-1, and also reduced the proportion of total CO2 assimilation that occurred at night from c. 90% to c. 40%. Decreasing day temperatures (30 to 10°C) had little effect on total daily CO2 assimilation in warm (25°C) nights, but reduced it in cooler (15°C) nights. At day temperatures of <152C, CO2 assimilation took place predominantly (60-100%) in the photoperiod. In cool (10°C) days, the normal inverted stomatal rhythm of CAM plants was reversed; leaf conductance was high (c. 1.0 mm s-1) throughout the photoperiod and a large CO2 efflux was observed, lasting c. 2 h, at the beginning of the dark period. Leaf conductance of pineapples, by day and by night, is strongly influenced by ambient temperatures, with cool conditions favouring stomatal opening.

The assessment of seasonal yield using some Stylosanthes guyanensis accessions in humid tropical and sub-tropical environments

1977 ◽  
Vol 17 (86) ◽  
pp. 425 ◽  
Author(s):  
LA Edye ◽  
WT Williams ◽  
RL Burt ◽  
B Grof ◽  
SL Stillman ◽  
...  
Keyword(s):  
Growth Rate ◽  
High Growth ◽  
Growth Period ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Growth Patterns ◽  
Seasonal Growth ◽  
Seasonally Dry ◽  
Tropical Environments ◽  
Dry Tropics

The seasonal growth patterns of some S. guyanensis accessions were compared in three humid environments at South Johnstone (extended rainfall tropics), 'Heathlands' (seasonally dry tropics) and Cooroy (humid sub-tropics). The accessions were selected mainly for their productivity in previously described small mown sward experiments over three years at each site. Previous methods of presenting seasonal growth patterns are reviewed, and a new, simpler method of presentation is defined. Growth was highly seasonal at all sites. There was no growth during July to November at 'Heathlands' and Cooroy due to moisture and temperature limitations respectively. At South Johnstone growth was continuous but depressed in August and December with limitations due to both soil moisture and temperature: the maximum growth rate was 22 times the minimum growth rate. The accessions differed markedly in their growth patterns at each site. In general, the yield differences between accessions were greater at the beginning and end of the growing season than during the peak growth period. The highest yielding accessions at each site had high growth rates spread over a long period. The yield distribution and persistence of Q8231 and 46589C seemed superior to existing cultivars in tropical and sub-tropical environments respectively

Carbon Isotope Discrimination measured Concurrently with Gas Exchange to Investigate CO2 Diffusion in Leaves of Higher Plants

1986 ◽  
Vol 13 (2) ◽  
pp. 281 ◽  
Author(s):  
JR Evans ◽  
TD Sharkey ◽  
JA Berry ◽  
GD Farquhar
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Carbon Isotope ◽  
Higher Plants ◽  
Isotope Composition ◽  
Co2 Assimilation ◽  
Carbon Isotope Composition ◽  
C3 Plants ◽  
Isotopic Discrimination ◽  
Co2 Diffusion

Conventional gas-exchange techniques that measure the stomatal conductance and rate of CO2 assimilation of leaves were combined with measurements of the carbon isotope composition of CO2 in air passing over a leaf. Isotopic discrimination during uptake was determined from the difference in the carbon isotope composition of air entering and leaving the leaf chamber. Isotopic discrimination measured over the short term correlated strongly with that determined from combusted leaf material. Environmental conditions were manipulated to alter the relative influences of stomatal conductance and carboxylation on the discrimination of carbon isotopes by intact leaves. With C3 plants, discrimination increased as the gradient in partial pressure of CO2 across the stomata decreased. For C4 plants there was little change in discrimination despite substantial changes in the diffusion gradient across the sto- mata. These results are consistent with, and provide the first direct experimental support for, theoretical equations describing discrimination during photosynthesis. Despite uncertainties about various processes affecting carbon isotope composition, the resistance to the transfer of CO2 from the intercellular airspaces to the sites of carboxylation in the mesophyll chloroplasts was estimated using this technique. For wheat the estimated resistance was 1.2-2.4 m2 s bar mol -1.

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