An Exploration of the Carbon Economy of the Tobacco Plant. III. Gas Exchange of Leaves in Relation to Position on the Stem, Ontogeny and Nitrogen Content

1974 ◽  
Vol 1 (4) ◽  
pp. 551 ◽  
Author(s):  
HM Rawson ◽  
C Hackett
Keyword(s):  
Gas Exchange ◽  
Nitrogen Content ◽  
Time Course ◽  
Dark Respiration ◽  
Tobacco Plant ◽  
Net Photosynthesis ◽  
Developmental Time ◽  
Leaf Ontogeny ◽  
Similar Time ◽  
Carbon Economy

Tobacco plants were grown in sunlit, controlled-environment cabinets, and their growth and gas exchange were followed from shortly after emergence to 90 days from sowing. There were three major findings: 1. Summed over all leaves, dark respiration remained at 6-7% of net photosynthesis for a lengthy period (50-90 days from sowing), but in younger plants the fraction reached as high as 18%. 2. In the 12 leaves monitored from their emergence to full expansion, net photosynthesis (Pn) followed a similar time course, even though the first and last leaves in this group emerged nearly 40 days apart and there was a 100-fold difference in final area (Amax). For a sequence of nine of these leaves, the agreement was so close that their photosynthetic histories could be represented by a single relationship with developmental time. Peak Pn was consistently attained at about 37% Amax, when peak dA/dt occurred, and it was held for only 3-5 days. The subsequent decline reduced Pn to less than one-third of peak Pn at Amax. 3. Data for the nitrogen content (w/w) of the leaves after 37% Amax could be combined in a manner similar to that described for Pn. Pn, nitrogen content and leaf ontogeny were therefore directly related after peak Pn had been attained. The bearing of these findings on the study of photosynthesis in dicotyledonous species is discussed.

Response of Gas Exchange in Jointed Goatgrass (Aegilops cylindrica) to Environmental Conditions

Weed Science ◽  
1989 ◽  
Vol 37 (4) ◽  
pp. 562-569 ◽  
Author(s):  
David R. Gealy
Keyword(s):  
Soil Moisture ◽  
Gas Exchange ◽  
Environmental Conditions ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Soil Matric Potential ◽  
Dark Respiration Rate ◽  
Matric Potential ◽  
Aegilops Cylindrica ◽  
Jointed Goatgrass

Gas exchange of jointed goatgrass leaves was affected by temperature, irradiance level, and soil matric potential. Net photosynthesis of leaves under saturating irradiance (PPFD3= 1850 (μE·m–2·s−1) was optimum at about 20 C. At 25 C, net photosynthesis was nearly 90% of maximum at a PPFD of 800 μE·m–2·−1. Transpiration, and presumably water use, increased steadily with temperature from 10 to 40 C. Dark respiration rate and compensation points for light and for CO2increased exponentially, or nearly so, from 10 to 40 C. Soil moisture deficits of −130 kPa reduced net photosynthesis and transpiration by about 30 and 55%, respectively, compared to well-watered plants.

Photorespiration and internal recycling of CO2 in the submersed angiosperm Scirpus subterminalis

1980 ◽  
Vol 58 (6) ◽  
pp. 591-598 ◽  
Author(s):  
Morten Søndergaard ◽  
Robert G. Wetzel
Keyword(s):  
Gas Exchange ◽  
Time Course ◽  
Free Water ◽  
Net Photosynthesis ◽  
Open Water ◽  
Dry Weight ◽  
Experimental Conditions ◽  
Gas Exchange Characteristics ◽  
Gas Space ◽  
A Minor

The presence and magnitude of photorespiration in the submersed freshwater angiosperm Scirpus subterminalis Torr. was investigated by gas-exchange characteristics in an open water-flow system. The minimal rates of photorespiration during active photosynthesis were measured by following the time course of differential 14CO2 and 12CO2 uptake. At 8 mg O2 L−1 (equal to oxygen saturation at 20 °C), the rate was 0.4 μg C (mg organic dry weight)−1 h−1, which was about 10% of net photosynthesis under the experimental conditions. Increasing the oxygen concentration to 30 mg O2 L−1, enhanced photorespiration to 30% of net photosynthesis. It was shown that the concentration of oxygen affected net photosynthesis, CO2 evolution into CO2-free water in the light, the post-illumination CO2 burst, and the CO2 compensation point.The effect of the internal gas space on recycling of CO2 was investigated by comparing gas-exchange by intact and sectioned leaves. About 30% of the CO2 of photorespiratory origin was recycled internally within the lacunal system. The gas-exchange characteristics of Scirpus were similar to those observed in terrestrial C3 species although of a minor magnitude and a different time course. The ecological implications of these finds are discussed.

Temperature relations of gas exchange in altitudinal populations of Taraxacum officinale

1977 ◽  
Vol 55 (19) ◽  
pp. 2496-2502 ◽  
Author(s):  
Paul R. Kemp ◽  
George J. Williams III ◽  
David S. May
Keyword(s):  
Gas Exchange ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Taraxacum Officinale ◽  
Verbascum Thapsus ◽  
Respiration Rates ◽  
Hill Activity ◽  
Population Origin ◽  
Weedy Species ◽  
Temperature Responses

Taraxacum officinale plants representative of three altitudinally diverse populations were grown under uniform conditions. Temperature responses of net photosynthesis, photorespiration, and transpiration were obtained from four plants of each population over the range of 10 to 40 °C at saturating irradiances(1000 μE ∙ m−2 ∙ s−1). Dark respiration rates were obtained from the same plants over the range of 10 to 30 °C. All plants exhibited similar gas exchange responses to temperature regardless of population origin. Maximum rates of net photosynthesis occurred near 20 °C in all plants and averaged 20.8 mg CO2 ∙ dm−2 ∙ h−1 (mean of 12 plants). Dark respiration and photorespiration rates increased nearly linearly with temperature in all plants. These results are in contrast with previous studies of the same populations in which differences in Hill activity and succinate dehydrogenase activity were reported. However, the photosynthetic patterns and lack of genetic differentiation of photosynthesis are similar to the results obtained for another weedy species, Verbascum thapsus, along the same altitudinal transect.

Effect of Nitrogen Content on the Photosynthetic Characteristics of Sunflower Leaves

1993 ◽  
Vol 20 (3) ◽  
pp. 251 ◽  
Author(s):  
DJ Connor ◽  
AJ Hall ◽  
VO Sadras
Keyword(s):  
Nitrogen Content ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Leaf Nitrogen ◽  
Mean Value ◽  
Life Cycles ◽  
High Irradiance ◽  
Response Curves ◽  
Unit Leaf ◽  
Wide Range

Photosynthesis-irradiance response curves and leaf nitrogen contents were measured weekly by destructive sampling over the life cycles of leaves 10, 15, 20 and 25 of sunflower plants (cv. Prosol 35) grown in large pots in the open under optimum conditions of temperature and high irradiance. Individual leaf responses were adequately described by a hyperbola of three parameters, viz. Pmax, the rate of photosynthesis in saturating irradiance; R, the rate of dark respiration adjusted for temperature (30�C); and ε, the apparent quantum efficiency of photosynthesis at low irradiance. Pmax (range 0-40 μmol CO2 m-2 s-1) and R (0-4 μmol CO2 m-2 s-1) were non-linearly related to nitrogen content per unit leaf area (NL) (range 0.3-2.9 g N m-2) across all leaf positions and for all leaf ages. ε (mean value 0.050 mol mol-1, s.e. 0.001) was independent of NL. The equations for net photosynthesis derived from pot studies were shown to explain (r2 =0.80) leaf photosynthesis in a crop of the same cultivar over a wide range of NL and irradiance.

scholarly journals Canopy Position Affects Light Response Curves for Gas Exchange Characteristics of Apple Spur Leaves

1992 ◽  
Vol 117 (3) ◽  
pp. 467-472 ◽  
Author(s):  
Richard J. Campbell ◽  
Richard P. Marini ◽  
Jeffrey B. Birch
Keyword(s):  
Gas Exchange ◽  
Dark Respiration ◽  
Incident Light ◽  
Light Response ◽  
Net Photosynthesis ◽  
Response Curves ◽  
Light Response Curves ◽  
Light Levels ◽  
Canopy Position ◽  
Gas Exchange Characteristics

Light response curves for gas exchange characteristics were developed for spur leaves of `Stayman' and `Delicious' apple (Malus domestica Borkh.) from interior, intermediate, and exterior canopy positions throughout the season. At full bloom (FB), before full leaf expansion, exterior leaves had higher maximum rates of net photosynthesis (Pn), and a statistically different Pn light response curve than the interior leaves. Intermediate leaves had intermediate Pn rates and light response curves. Pn light response curves for all three `Delicious' canopy positions differed from each other from FB + 6 weeks until the end of the season. Interior leaves had maximum Pn rates of only 50% to 60% of those for the exterior leaves from FB + 10 weeks until the end of the season. Light saturation levels were higher for the exterior leaves than for interior or intermediate leaves. Exterior leaves had a tendency throughout the season for higher quantum efficiency of Pn at subsaturating light levels than interior or intermediate leaves. Stomatal conductance was higher for the exterior than the interior or intermediate leaves of `Delicious' on all dates. Water-use efficiency was equivalent among all leaves. Exterior leaves had higher specific leaf weight, dark respiration rates, and incident light levels on all dates than interior or intermediate leaves.

An Exploration of the Carbon Economy of the Tobacco Plant. II. Patterns of Leaf Growth and Dry Matter Partitioning

1974 ◽  
Vol 1 (2) ◽  
pp. 271 ◽  
Author(s):  
C Hackett ◽  
HM Rawson
Keyword(s):  
Gas Exchange ◽  
Dry Matter ◽  
Tobacco Plant ◽  
Leaf Growth ◽  
Leaf Size ◽  
Growth Function ◽  
Leaf Expansion ◽  
Growth Data ◽  
Dry Matter Partitioning ◽  
Carbon Economy

As a sequel to calculations made in Part I about the carbon economy of the tobacco plant, a short-day variety of tobacco (Nicotiana tabacum L. cv. Mammoth 17L) was grown at controlled temperatures in two contrasting photoperiods (13 and 9 h) and the growth and gas exchange of the plants were determined as frequently as possible during the period 30–100 days from sowing. This paper describes aspects of the leaf emergence, leaf expansion, floral development, and dry matter partitioning in these plants. Part III will present the gas-exchange data. The most striking finding from the growth data concerned leaf expansion. The application of curve-fitting techniques showed that the expansion of each leaf studied could be accurately described by the Gompertz growth function, which implied that the maximum absolute rate of expansion had been achieved quite early in the leaf's development, at about 37% of full expansion. Furthermore, in all but the juvenile leaves, the time-spread of expansion was similar, despite up to 10-fold differences in the final area of the leaves due to photoperiod and position on the stem. Other relationships observed in the data seemed of fundamental interest. Attention is drawn (1) to the smooth progression in final leaf size with progress up the stem, and (2) to the changes with time in the ratio of the relative growth rates of the major plant parts, but whether these relationships, and those between leaf expansion and time, are typical of tobacco will remain uncertain until comparable studies are performed. * Part I, Aust. J. Biol. Sci., 1973, 26, 1057–71.

Comparative gas exchange physiology in the Daucus carota complex

1978 ◽  
Vol 56 (15) ◽  
pp. 1739-1743 ◽  
Author(s):  
Ernest Small ◽  
R. L. Desjardins
Keyword(s):  
Gas Exchange ◽  
Water Use ◽  
Daucus Carota ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Wild Populations ◽  
Stomatal Frequency ◽  
Rate Of Photosynthesis ◽  
Taxonomic Groups

Rates of net photosynthesis, transpiration, and dark respiration of seven populations representing the diversity of the Daucus carota complex were measured. The two taxonomic groups of this complex proved physiologically distinguishable, with subspecies aggregate gingidium possessing lower capacities for photosynthesis and transpiration and a lower frequency of stomata than subspecies aggregate carota. In comparison with wild populations of the complex, cultivars manifested greater efficiency of photosynthesis with respect to water use, possibly the result of an increased demand for photosynthate in domesticated populations. The highest rate of photosynthesis was exhibited by a vigorous, primitive, Asian cultivar, which also possessed the highest stomatal frequency.

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.

Field assessment of Douglas-fir somatic and zygotic seedlings with respect to gas exchange, water relations, and frost hardiness

2002 ◽  
Vol 32 (10) ◽  
pp. 1822-1828 ◽  
Author(s):  
A Benowicz ◽  
S C Grossnickle ◽  
Y A El-Kassaby
Keyword(s):  
Gas Exchange ◽  
Water Relations ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Douglas Fir ◽  
Frost Hardiness ◽  
Xylem Water Potential ◽  
Spring Frost ◽  
Intrinsic Water Use Efficiency ◽  
Stock Types

Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) zygotic seedlings and seedlings produced through somatic embryogenesis were grown in a field test on southern Vancouver Island, British Columbia. The two stock types were compared in a number of adaptive attributes evaluated during two growing seasons (1999 and 2000). The attributes were related to gas exchange, water relations, phenology, and fall frost hardiness. In both years, somatic and zygotic seedlings had similar rates of net photosynthesis in optimum and reduced light conditions, similar mesophyll conductance, and dark respiration rates. Small differences (P [Formula: see text] 0.05) were found for water relation attributes measured on irrigated plants: intrinsic water use efficiency (WUEi), transpiration (E), stomatal conductance (gwv) and midday xylem water potential (Ψ). Somatic seedlings had marginally higher E and gwv and lower Ψ in 2000 and lower WUEi in 1999 and 2000. Zygotic seedlings had higher WUEi because of their lower gwv while maintaining the same rates of net photosynthesis as somatic seedlings. There were no differences between somatic and zygotic seedlings in frost hardiness throughout the fall. Zygotic and somatic seedlings had similar timing of spring bud break pointing to a comparable level of spring frost hardiness in both stock types. Findings from this study indicate that somatic and zygotic seedlings had a similar pattern of physiological performance throughout 2 years of assessment.

Effect of frond age on frond elongation, gas exchange, and water relations in the ostrich fern (Matteuccia struthiopteris)

1984 ◽  
Vol 62 (10) ◽  
pp. 2094-2100 ◽  
Author(s):  
R. K. Prange ◽  
D. P. Ormrod ◽  
J. T. A. Proctor
Keyword(s):  
Gas Exchange ◽  
Water Potential ◽  
Respiration Rate ◽  
Dark Respiration ◽  
Water Status ◽  
Net Photosynthesis ◽  
Dark Respiration Rate ◽  
Pressure Potential ◽  
Apical Bud ◽  
Diffusive Resistance

The effect of frond age in the ostrich fern (Matteuccia struthiopteris) upon changes in frond elongation, frond water status (osmotic, pressure, and total water potential), and gas exchange (diffusive resistance, net photosynthesis rate, and dark respiration rate) was examined. The maximum elongation rate in the youngest fronds was 2.83 mm h−1 and occurred between 1500 and 2100 hours. Growth of individual fronds was completed in ca. 16–20 days after emergence from the apical bud. As a frond approached final length, both the dark respiration rate and rate of daily elongation decreased. Compared with mature fronds, young fronds (5 to 8 days old) had higher dark respiration rates and lower net photosynthesis rates. They also had higher osmotic potentials and lower pressure potentials and predawn diffusive resistances. In the youngest fronds (3 and 6 days old) the fastest elongation rates occurred at the lowest water potentials. This phenomenon may be an example of "growth-induced water potential." The increase in pressure potential and decrease in osmotic potential as the frond approached full expansion on day 16 indicates an "apparent" osmotic adjustment which was probably due to a decrease in the yielding properties of the cell walls while solutes continued to accumulate in the tissue. At full expansion further accumulation appeared to stop, suggesting that the frond had increased net solute export.

Sign in / Sign up

Export Citation Format

Share Document