Alterations in the physiology of CO2 exchange in tomato plants grown in CO2-enriched atmospheres

1980 ◽  
Vol 58 (20) ◽  
pp. 2181-2189 ◽  
Author(s):  
Peter R. Hicklenton ◽  
Peter A. Jolliffe
Keyword(s):  
Growth Rate ◽  
Gas Exchange ◽  
Early Stage ◽  
Atmospheric Oxygen ◽  
Net Photosynthesis ◽  
Stomatal Resistance ◽  
Co2 Exchange ◽  
Acid Oxidase ◽  
Bisphosphate Carboxylase ◽  
Tomato Plants

Young, greenhouse-grown tomato plants were transferred to growth cabinets where they were maintained in normal air (0.03% CO2) or in air enriched to 0.1 or 0.5% CO2. CO2 enrichment increased net assimilation rate but decreased leaf area ratio. As a result, relative growth rate was greatest at 0.1% CO2 and was less in 0.5% CO2 than in 0.03% CO2. Gas exchange measurements were made on the third true leaf of plants from different CO2 regimes. They indicated that growth under conditions of CO2 enrichment affected photosynthesis at an early stage of leaf development (leaf plastochron index (PI) = 5) but not at a later stage (PI = 10.5). The effects were linked to changes in mesophyll resistance, not stomatal resistance. At PI = 5 and under equivalent test conditions of irradiance and CO2 concentration, net photosynthesis tended to be increased following growth in 0.1% CO2 but was decreased or unchanged by 0.5% CO2. Young leaves developed in 0.1% CO2 were less subject to photosynthetic inhibition by atmospheric oxygen and had low CO2 compensation points. CO2 enrichment also affected the activities of the enzymes ribulose-1,5-bisphosphate carboxylase and glycolic acid oxidase and the enzyme responses corresponded well with the gas exchange responses. The results indicate that photosynthetic adaptations may occur in response to the concentration of CO2 present during growth, and that enrichment to concentrations much above 0.1% CO2 may be detrimental to net photosynthesis and growth rate.

scholarly journals Parameterization of a coupled CO<sub>2</sub> and H<sub>2</sub>O gas exchange model at the leaf scale of <i>Populus euphratica</i>

2010 ◽  
Vol 14 (3) ◽  
pp. 419-431 ◽  
Author(s):  
G. F. Zhu ◽  
X. Li ◽  
Y. H. Su ◽  
C. L. Huang
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Electron Transport Rate ◽  
Populus Euphratica ◽  
Coupled Model ◽  
Net Photosynthesis ◽  
Combined Model ◽  
Validation Data ◽  
Bisphosphate Carboxylase ◽  
Diurnal Patterns

Abstract. The following two models were combined to simultaneously predict CO2 and H2O gas exchange at the leaf scale of Populus euphratica: a Farquhar et al. type biochemical sub-model of photosynthesis (Farquhar et al., 1980) and a Ball et al. type stomatal conductance sub-model (Ball et al., 1987). The photosynthesis parameters [including maximum carboxylation rate allowed by ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation rate (Vcmax), potential light-saturated electron transport rate (Jmax), triose phosphate utilization (TPU) and day respiration (Rd)] were determined by using the genetic algorithm (GA) method based on A/Ci data. Values of Vcmax and Jmax standardized at 25 °C were 75.09±1.36 (mean ± standard error), 117.27±2.47, respectively. The stomatal conductance sub-model was calibrated independently. Prediction of net photosynthesis by the coupled model agreed well with the validation data, but the model tended to underestimate transpiration rates. Overall, the combined model generally captured the diurnal patterns of CO2 and H2O exchange resulting from variation in temperature and irradiation.

Characteristics of pea leaves and their relationships to photosynthetic CO2 exchange in the field

1983 ◽  
Vol 61 (12) ◽  
pp. 3283-3292 ◽  
Author(s):  
J. D. Mahon ◽  
S. L. A. Hobbs ◽  
S. O. Salminen
Keyword(s):  
Direct Determination ◽  
Stomatal Resistance ◽  
Co2 Exchange ◽  
Photosynthetic Performance ◽  
Time Of Day ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Carboxylase Activity ◽  
Single Experiment ◽  
Bisphosphate Carboxylase

Photosynthetic CO2 exchange rate (CER) was determined in attached leaflets of field-grown peas (Pisum sativum L.) Three populations of genotypes were studied in different field locations and years. In 1 year, CER, leaf characteristics, and meteorological factors were measured in parallel at different times of the day and season. Differences in CER across environments or time of day were related to differences in stomatal resistance; however, changes during the season, which might be of environmental or developmental origin, were not. Genotype ranking for CER was largely independent of measuring time, field location, and year. None of the leaf characters which have been suggested as simple assays for photosynthetic ability (specific leaf weight, chlorophyll content, stomatal resistance) was consistently related to CER over several tests. In the single experiment in which they were determined, ribulose bisphosphate carboxylase activity, leaf soluble protein content, and the difference in CER at 2 and 20 kPa O2 were also not correlated with CER. The O2 effect expressed as a percentage of CER at 2 kPa O2 and the slope of the light response above 50 nE cm−2 s−1 were significantly correlated to CER, but neither is suitable for predicting CER in different genotypes. A significant multiple regression of CER on stomatal resistance, total chlorophyll, and ribulose bisphosphate carboxylase activity suggests that the genetic control of CER may involve several characters. In this case, direct determination of CO2 exchange may be the easiest and most reliable way of assessing genetic differences in photosynthetic performance.

scholarly journals Parameterization of the coupling CO<sub>2</sub> and H<sub>2</sub>O gas exchange model at the leaf scale of <i>Populus euphratica</i> tree

2009 ◽  
Vol 6 (5) ◽  
pp. 6503-6534
Author(s):  
G. Zhu ◽  
X. Li ◽  
Y. Su ◽  
C. Huang
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Populus Euphratica ◽  
Coupled Model ◽  
Net Photosynthesis ◽  
Data Sets ◽  
Validation Data ◽  
Bisphosphate Carboxylase ◽  
Diurnal Patterns ◽  
Ribulose 1

Abstract. The following two models were combined to predict simultaneously CO2 and H2O gas exchange at the leaf scale of Populus euphratica: a Farquhar et al. type biochemical sub-model of photosynthesis (Farquhar et al., 1980) and a Ball et al. type stomatal conductance sub-model (Ball et al., 1987). The photosynthesis parameters, Vcmax, Jmax, TPU, and Rd (maximum carboxylation rate allowed by ribulose 1·5-bisphosphate carboxylase/oxygenase (Rubisco), rate of phosynthetic electron transport, triose phosphate use, and day respiration) at the measurement temperature were determined by using the genetic algorithm (GA) method based on A/Ci data sets. The stomatal conductance sub-model was calibrated independently. Prediction of net photosynthesis by the coupled model agreed well with the validation data, but the model tended to underestimate rates of transpiration. Overall, the combined model generally captured the diurnal patterns of CO2and H2O exchange resulting from variation in temperature and irradiation.

CO2 EXCHANGE RATES AND STOMATAL DIFFUSIVE RESISTANCE IN SOYBEAN EXPOSED TO O3 AND SO2

1985 ◽  
Vol 65 (2) ◽  
pp. 267-274 ◽  
Author(s):  
B. I. CHEVONE ◽  
Y. S. YANG
Keyword(s):  
Exchange Rates ◽  
Net Photosynthesis ◽  
Stomatal Resistance ◽  
Co2 Exchange ◽  
Carbon Dioxide Exchange ◽  
Simultaneous Application ◽  
Diffusive Resistance ◽  
Before And After ◽  
Glycine Max L ◽  
Pollutant Mixtures

Soybean (Glycine max (L.) Merr. ’Essex’) plants, 21–24 days old, were exposed to 400 μg/m3 (0.20 μL/L) ozone (O3) and 1865 μg/m3 (0.70 μL/L) sulfur dioxide (SO2) in various combinations. Fumigation was administered for 2 h either as single pollutants (O3 and SO2), simultaneously (O3 + SO2), or in overlapping pollutant combinations (O3 for 1 h followed by O3 + SO2 or SO2 for 1 h followed by SO2 + O3). Carbon dioxide exchange rates (CER) of trifoliolate leaves were measured during the fumigations, and stomatal resistance to H2O was determined immediately before and after pollutant exposure. At the end of a 2-h exposure, O3 and SO2, administered separately, did not significantly affect CER. Exposure to O3 followed by O3 + SO2, SO2 followed by SO2 + O3, and continuous O3 + SO2 significantly reduced CER to 62, 41 and 33% of preexposure rates, respectively. Stomatal resistance was not significantly altered by pollutant fumigation except in the simultaneous application of O3 + SO2 where an 11% decrease occurred. Reductions in CER in response to fumigation were not attributed to changes in stomatal resistance, but appeared to result from changes in mesophyll resistance. A proposed mechanism for pollutant-induced reduction in CER is discussed.Key words: Air pollution, net photosynthesis, pollutant mixtures

scholarly journals THE EFFECT OF TEMPERATURE ON CARBON GAIN IN ALSTROEMERIA

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 649e-649
Author(s):  
E.D. Leonardos ◽  
M.J. Tsujita ◽  
B. Grodzinski ◽  
T.J. Blom
Keyword(s):  
Gas Exchange ◽  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
Carbon Assimilation ◽  
Net Photosynthesis ◽  
Stomatal Resistance ◽  
Effect Of Temperature ◽  
Carbon Gain ◽  
Leaf Transpiration ◽  
Whole Plant

Leaf and whole plant gas exchange (net photosynthesis Pn, dark respiration Dr, transpiration Tr, and resistance R) of `Jacqueline' Alstroemeria, grown in pots inside a greenhouse, were measured under lab conditions using an openflow and a semi-closed system respectively. Temperature responses of apical fully expanded leaves, on flowering and non-flowering shoots, showed an optimum range for net photosynthesis (Pn) from 15 to 20 °C. Above 25 °C Pn dropped considerably as temperature increased. Leaf transpiration rates over the same range of temperature showed a similar decrease, indicating that low leaf Pn rates at higher temperatures were due in part to increased stomatal resistance. Whole plant photosynthetic response to temperature was similar to that of leaf gas exchange. The optimum temperature range for whole plant Pn was from 12 to 17 °C. These results show that moderately low temperatures are essential for carbon assimilation and efficient water use in Alstroemeria. Temperature interactions with other environmental factors will also be presented in models describing Pn rates as a function of irradiance, CO2 concentration, and temperature.

Pattern Formation in Thin Polymer Films: A New Morphology

2000 ◽  
Vol 629 ◽  
Author(s):  
Jean-Loup Masson ◽  
Peter F. Green
Keyword(s):  
Growth Rate ◽  
Pattern Formation ◽  
Early Stage ◽  
Structural Evolution ◽  
Distinct Form ◽  
Thin Polymer Films ◽  
Intermediate Morphology ◽  
Thin Polymer ◽  
Nonwetting Liquid ◽  
Cylindrical Holes

ABSTRACTResearchers have shown that thin, nonwetting, liquid homopolymer films dewet substrates, forming patterns that reflect fluctuations in the local film thickness. These patterns have been shown to be either discrete cylindrical holes or bicontinuous “spinodal-like” patterns. In this paper we show the existence of a new morphology. During the early stage of dewetting, discrete highly asymmetric holes appear spontaneously throughout the film. The nucleation rate of these holes is faster than their growth rate. The morphology of the late stage of evolution, after 18 days, is characterized by a bicontinuous pattern, distinct form conventional spinodal dewetting patterns. This morphology has been observed for a range of film thicknesses between 7.5 and 21nm. The structural evolution of this intermediate morphology is discussed.

scholarly journals Public Compliance With Social Distancing Measures and SARS-CoV-2 Spread

2021 ◽  
pp. 003335492110112
Author(s):  
Hongjie Liu ◽  
Chang Chen ◽  
Raul Cruz-Cano ◽  
Jennifer L. Guida ◽  
Minha Lee
Keyword(s):  
Growth Rate ◽  
Reproduction Number ◽  
Early Stage ◽  
Human Mobility ◽  
The United States ◽  
Density Change ◽  
Regression Coefficients ◽  
Daily Growth Rate ◽  
Daily Growth ◽  
Social Distancing

Objective We quantified the association between public compliance with social distancing measures and the spread of SARS-CoV-2 during the first wave of the epidemic (March–May 2020) in 5 states that accounted for half of the total number of COVID-19 cases in the United States. Methods We used data on mobility and number of COVID-19 cases to longitudinally estimate associations between public compliance, as measured by human mobility, and the daily reproduction number and daily growth rate during the first wave of the COVID-19 epidemic in California, Illinois, Massachusetts, New Jersey, and New York. Results The 5 states mandated social distancing directives during March 19-24, 2020, and public compliance with mandates started to decrease in mid-April 2020. As of May 31, 2020, the daily reproduction number decreased from 2.41-5.21 to 0.72-1.19, and the daily growth rate decreased from 0.22-0.77 to –0.04 to 0.05 in the 5 states. The level of public compliance, as measured by the social distancing index (SDI) and daily encounter-density change, was high at the early stage of implementation but decreased in the 5 states. The SDI was negatively associated with the daily reproduction number (regression coefficients range, –0.04 to –0.01) and the daily growth rate (from –0.009 to –0.01). The daily encounter-density change was positively associated with the daily reproduction number (regression coefficients range, 0.24 to 1.02) and the daily growth rate (from 0.05 to 0.26). Conclusions Social distancing is an effective strategy to reduce the incidence of COVID-19 and illustrates the role of public compliance with social distancing measures to achieve public health benefits.

Red spruce seedling gas exchange in response to elevated CO2, water stress, and soil fertility treatments

1994 ◽  
Vol 24 (5) ◽  
pp. 954-959 ◽  
Author(s):  
L.J. Samuelson ◽  
J.R. Seiler
Keyword(s):  
Water Stress ◽  
Gas Exchange ◽  
Soil Fertility ◽  
Net Photosynthesis ◽  
Growing Season ◽  
Red Spruce ◽  
Fertility Treatment ◽  
Sink Strength ◽  
Growth Enhancement ◽  
Growing Seasons

The interactive influences of ambient (374 μL•L−1) or elevated (713 μL•L−1) CO2, low or high soil fertility, well-watered or water-stressed treatment, and rooting volume on gas exchange and growth were examined in red spruce (Picearubens Sarg.) grown from seed through two growing seasons. Leaf gas exchange throughout two growing seasons and growth after two growing seasons in response to elevated CO2 were independent of soil fertility and water-stress treatments, and rooting volume. During the first growing season, no reduction in leaf photosynthesis of seedlings grown in elevated CO2 compared with seedlings grown in ambient CO2 was observed when measured at the same CO2 concentration. During the second growing season, net photosynthesis was up to 21% lower for elevated CO2-grown seedlings than for ambient CO2-grown seedlings when measured at 358 μL•L−1. Thus, photosynthetic acclimation to growth in elevated CO2 occurred gradually and was not a function of root-sink strength or soil-fertility treatment. However, net photosynthesis of seedlings grown and measured at an elevated CO2 concentration was still over 2 times greater than the photosynthesis of seedlings grown and measured at an ambient CO2 concentration. Growth enhancement by CO2 was maintained, since seedlings grown in elevated CO2 were 40% larger in both size and weight after two growing seasons.

Photosynthesis and Transpiration in Damaged and Undamaged Spruce Trees

1996 ◽  
Vol 51 (3-4) ◽  
pp. 200-210 ◽  
Author(s):  
Aloysius Wild ◽  
Peter Sabel ◽  
Lucia Wild-Peters ◽  
Ursula Schmieden
Keyword(s):  
Gas Exchange ◽  
Water Potential ◽  
Natural Habitat ◽  
Late Summer ◽  
Net Photosynthesis ◽  
Diurnal Course ◽  
Physiological Homeostasis ◽  
Use Efficiency ◽  
Needle Loss ◽  
Light Saturation Curves

Abstract The investigations presented here focus on the CO2/H2O gas exchange in damaged and undamaged spruce trees while using open-air measurements as well as measurements under defined conditions in the laboratory. The studies were performed at two different sites in the Hunsrück and the Westerwald mountains. In the laboratory the CO2/H2O gas exchange was measured on detached branches under controlled conditions in the course of two years. CO2 saturation curves were also generated. In addition CO2 compensation points were deter­ mined employing a closed system. In the natural habitat diurnal course measurements of photosynthesis and transpiration as well as light-saturation curves for photosynthesis were performed. In parallel with the photosynthesis and transpiration measurements, measurements of the water potential were taken at both locations. The photosynthetic capacity and transpiration rate show a typical annual course with pronounced maxima in spring and late summer and minima in summer and winter. The needles of the damaged trees exhibit higher transpiration rates and a distinct reduction in photosyn­ thesis than the needles of the undamaged trees during two seasons. The diurnal course measurements of net photosynthesis and transpiration show a maximum in photosynthesis and transpiration in the afternoon in May and September, but a characteristic midday depression in July. Photosynthesis was markedly lower and transpiration higher in the needles of the damaged trees. The damaged trees show a lower increase in the light and CO2 saturation curves and higher CO2 compensation points as compared to the undamaged trees. The water potential reaches much lower values during the course of the day in needles of the dam­ aged trees. The reduction of the photosynthetic rate on one hand and the increase in transpiration on the other hand result in an extreme lowering of the water use efficiency in photosynthesis. The damage to the thylakoid membranes and to the guard cells obviously results in a pro­ found disturbance of the physiological homeostasis of the needles and could thus lead to premature needle loss.

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