Characterization of diurnal photosynthetic rhythms in the marine diatom Skeletonema costatum grown in synchronous culture under ambient and elevated CO2

2004 ◽  
Vol 31 (4) ◽  
pp. 399 ◽  
Author(s):  
Xiongwen Chen ◽  
Kunshan Gao
Keyword(s):  
Chlorophyll A ◽  
Elevated Co2 ◽  
Skeletonema Costatum ◽  
Co2 Enrichment ◽  
Light Period ◽  
Marine Diatom ◽  
Initial Slope ◽  
Co2 Uptake ◽  
Chlorophyll A Content ◽  
Ambient Co2

Photosynthetic performance was examined in Skeletonema costatum (Greville) Cleve. under 12 : 12-h light : dark (LD) cycle at ambient CO2 (350 μL L–1) and elevated CO2 (1000 μL L–1). At ambient CO2, the cellular chlorophyll a content, the light-saturated photosynthetic rate (Pm), the initial slope of the light saturation curves (α), the photochemical efficiency of PSII (Fv / Fm), the apparent carboxylating efficiency (ACE) and the photosynthetic affinity for CO2 [1 / Km(CO2)] all showed rhythmical changes with different amplitudes during the light period. The Pm had similar changing pattern in the light period with the ACE and 1 / Km(CO2) rather than with the α and Fv / Fm, indicating that rhythmical changes of photosynthetic capacity may be mainly controlled by the activity of C-reduction associated with CO2 uptake during the light period. The CO2 enrichment reduced the ACE and the affinity to CO2, and increased the α, cellular chlorophyll a content and Pm based on cell number. By contrast, the changing patterns of all photosynthetic parameters examined here during the light period had almost the same for cells grown at ambient CO2 and elevated CO2, suggesting that the photosynthetic rhythms of S. costatum are not affected by CO2 enrichment.

Responses of the apple plant to CO2 enrichment: changes in photosynthesis, sorbitol, other soluble sugars, and starch

1998 ◽  
Vol 25 (3) ◽  
pp. 293 ◽  
Author(s):  
Q. Pan ◽  
Z. Wang ◽  
B. Quebedeaux
Keyword(s):  
Elevated Co2 ◽  
Soluble Sugars ◽  
Co2 Enrichment ◽  
Carbohydrate Accumulation ◽  
Photosynthetic Rates ◽  
Mature Leaves ◽  
Whole Plant ◽  
Plant Photosynthesis ◽  
Apple Plant ◽  
Ambient Co2

There is no information on the effects of elevated [CO2] on whole-plant photosynthesis and carbohydrate metabolism in apple (Malus domestica Borkh.) and other sorbitol-translocating plants. Experiments were conducted in controlled growth chambers to evaluate how increases in [CO2] affect plant photosynthesis and carbon partitioning into soluble sugars and starch in apple leaves. Apple plants (cv. Gala), 1-year-old, were exposed to [CO2] of 200, 360, 700, 1000, and 1600 µL L-1 up to 8 d. Whole-plant net photosynthetic rates were analysed daily after [CO2] treatments. Newly expanded mature leaves were sampled at 1, 2, 4, and 8 d after [CO2] treatments for sorbitol, sucrose, glucose, fructose, and starch analysis. Midday whole-plant net photosynthetic rates increased linearly with increasing [CO2], but the differences in whole-plant photosynthesis between CO2-enrichment and ambient [CO2] treatments were less significant as apple plants acclimated to high atmospheric [CO2] for 8 d. Increases in [CO2] significantly increased sorbitol and starch, but did not affect sucrose concentrations. As a result, the ratios of starch to sorbitol and starch to sucrose at 8 d after [CO2] treatments were increased from 0.05 and 0.06 to 0.8 and 1.6 as [CO2] increased from ambient [CO2] (360 µL L-1) to 1000 µL L-1 [CO2], respectively. The sorbitol to sucrose ratio also increased from 1.3 to 2.2 as [CO2] increased from 360 to 1000 µL L-1. Elevated [CO2] enhanced the photosynthesis of apple plants and altered carbohydrate accumulation in mature leaves in favour of starch and sorbitol over sucrose.

Diel Periodicity of Chlorophyll a Concentration in Oregon Coastal Waters

1972 ◽  
Vol 29 (9) ◽  
pp. 1253-1259 ◽  
Author(s):  
Walter A. Glooschenko ◽  
Herbert Curl Jr. ◽  
Lawrence F. Small
Keyword(s):  
Light Intensity ◽  
Chlorophyll A ◽  
Coastal Waters ◽  
Dark Period ◽  
Skeletonema Costatum ◽  
Time Of Day ◽  
Light Period ◽  
Diel Periodicity ◽  
Low Light ◽  
Chlorophyll Precursor

Concentrations of chlorophyll a in phytoplankton exhibited a diel periodicity in Oregon coastal waters. Maximum surface concentrations often occurred around midnight and highest 25-m concentrations early in the evening (or even in late afternoon). Concentrations at intermediate depths fell in between and in a predictable progression with depth and time of day. Minimum chlorophyll a values occurred in the afternoon. No definite periodicity was established at 50 m.Laboratory studies with Skeletonema costatum demonstrated that the diel cycle of chlorophyll a per cell was related to the light intensity and duration to which cells were exposed. Highest concentrations of this pigment occurred early in the dark period and lowest concentrations in the light period when cells were grown under photoperiods of 9, 12, and 15 hr at a light intensity of approximately 1200 ft-c. Pigment bleaching probably was responsible for the low concentrations during the light period. The decline of chlorophyll a from the maximum early in the dark period began after the cells possibly became deficient in some chlorophyll precursor or energy-yielding substrate. Addition of an external carbon source during the dark period prolonged the high chlorophyll a concentrations in the dark before the decline began. Under low light (400 ft-c) chlorophyll a synthesis occurred only in the light. This phenomenon was most likely due to an insufficient amount of energy-yielding substrate or precursor synthesized during the low-light period, and the lack of bleaching in the light period at this lower intensity. The laboratory results were consistent with interpretations of the field data. A correction for diel pigment periodicity is recommended for models estimating photosynthesis from chlorophyll and light data and for oceanographic surveys during which sampling of chlorophyll a is carried out throughout the 24-hr day.

scholarly journals Soil-atmosphere exchange of CH<sub>4</sub>, CO<sub>2</sub>, NO<sub>x</sub>, and N<sub>2</sub>O in the Colorado Shortgrass Steppe following five years of elevated CO<sub>2</sub> and N fertilization

2003 ◽  
Vol 3 (3) ◽  
pp. 2691-2706 ◽  
Author(s):  
A. R. Mosier ◽  
P. Pendall ◽  
J. A. Morgan
Keyword(s):  
Elevated Co2 ◽  
Co2 Enrichment ◽  
Shortgrass Steppe ◽  
Plant Production ◽  
Trace Gas ◽  
No Emission ◽  
Ch4 Uptake ◽  
N2o Fluxes ◽  
The Impact ◽  
Ambient Co2

Abstract. An open-top-chamber (OTC) CO2 enrichment study was conducted in the Colorado shortgrass steppe to determine the effect of elevated CO2 (~720 mmol mol−1) on plant production, photosynthesis, and water use of this mixed C3/C4 plant community, soil nitrogen (N) and carbon (C) cycling and the impact of changes induced by \\CO2 on trace gas exchange. Weekly measurements of CO2, CH4, NOx and N2O fluxes within control (unchambered), ambient CO2 and elevated CO2 OTCs and soil water and temperature were measured at each flux measurement time from early April 1997, year round, through October 2001. Even though both aboveground plant biomass increased under elevated CO2 and soil moisture content was typically higher than under ambient CO2 conditions, none of the trace gas fluxes were significantly altered by CO2 enrichment over the 55 month period of observation. During early summer of 2002, following the removal of the open-top-chambers from the CO2 enrichment sites in October, we conducted a short term study to determine if soil microbial processes were altered in soils that had been exposed to double ambient CO2 concentrations during the growing season for the past five years. Microplots were established within each experimental site and 10 mm of water or 10 mm of water containing the equivalent of 10 g m−2 of ammonium nitrate-N was applied to the soil surface. Fluxes of CO2, CH4, NOx and N2O fluxes within control (unchambered), ambient CO2 and elevated CO2 OTCs soils at one to three day intervals for the next month. With water addition alone, CO2 and NO emission did not differ between ambient and elevated CO2 soils, while CH4 uptake rates were higher and N2O fluxes lower in elevated CO2 soils. Adding water and mineral N resulted in increased CO2 emissions, increased CH4 uptake and decreased NO emissions in elevated CO2 soils. The N addition study confirmed previous observations that soil respiration is enhanced under elevated CO2 and N immobilization is increased, thereby decreasing NO emission.

scholarly journals Effect of water addition and nitrogen fertilization on the fluxes of CH<sub>4</sub>, CO<sub>2</sub>, NO<sub>x</sub>, and N<sub>2</sub>O following five years of elevated CO<sub>2</sub> in the Colorado Shortgrass Steppe

2003 ◽  
Vol 3 (5) ◽  
pp. 1703-1708 ◽  
Author(s):  
A. R. Mosier ◽  
E. Pendall ◽  
J. A. Morgan
Keyword(s):  
Elevated Co2 ◽  
Plant Biomass ◽  
Co2 Enrichment ◽  
Surface Fluxes ◽  
Shortgrass Steppe ◽  
Water Addition ◽  
No Emission ◽  
Ch4 Uptake ◽  
N2o Fluxes ◽  
Ambient Co2

Abstract. An open-top-chamber (OTC) CO2 enrichment (~720 mmol mol-1) study was conducted in the Colorado shortgrass steppe from April 1997 through October 2001. Aboveground plant biomass increased under elevated CO2 and soil moisture content was typically higher than under ambient CO2 conditions. Fluxes of CH4, CO2, NOx and N2O, measured weekly year round were not significantly altered by CO2 enrichment over the 55 month period of observation. During early summer of 2002, following the removal of the open-top-chambers from the CO2 enrichment sites in October 2001, we conducted a short term study to determine if soil microbial processes were altered in soils that had been exposed to double ambient CO2 concentrations during the growing season for the past five years. Microplots were established within each experimental site and 10 mm of water or 10 mm of water containing the equivalent of 10 g m-2 of ammonium nitrate-N was applied to the soil surface. Fluxes of CO2, CH4, NOx and N2O fluxes within control (unchambered), ambient CO2 and elevated CO2 OTC soils were measured at one to three day intervals for the next month. With water addition alone, CO2 and NO emission did not differ between ambient and elevated CO2 soils, while CH4 uptake rates were higher and N2O fluxes lower in elevated CO2 soils. Adding water and mineral N resulted in increased CO2 emissions, increased CH4 uptake and decreased NO emissions in elevated CO2 soils. The N addition study confirmed previous observations that soil respiration is enhanced under elevated CO2 and N immobilization is increased, thereby decreasing NO emission.

scholarly journals The Effect of Different Nitrogen Levels and Enrichment CO2 on the Nutrient Contents of Rice Cultivars

1970 ◽  
Vol 44 (2) ◽  
pp. 241-246 ◽  
Author(s):  
MA Razzaque ◽  
MM Haque ◽  
QA Khaliq ◽  
ARM Solaiman
Keyword(s):  
Elevated Co2 ◽  
Nitrogen Concentration ◽  
Co2 Enrichment ◽  
Rice Cultivars ◽  
Nutrient Contents ◽  
Plant Parts ◽  
Nitrogen Levels ◽  
Open Field Condition ◽  
Ambient Co2 ◽  
Key Words Rice

An experiment was conducted during the July -December of 2003 to determine the nutrient compositions of rice under CO2 enrichment of different levels of nitrogen supply. Rice plants were grown from seedlings to maturity inside open top chamber under elevated CO2 (570 ±50) ppm, ambient CO2 (~360ppm) and open field condition. Leaves and root were analyzed for C, N, Zn and Mg. C content was higher in the all plant parts of rice grown at elevated CO2 compare than ambient CO2 and field grown rice. Increased N supplies also increase C content of the plants. Nitrogen concentration was reduced in elevated CO2 compare than other grown condition. Modern variety (BRRIdhan 39) contained higher C than local cultivars (Khaskani and Shakkorkhora). Nitrogen concentration was decreased under elevated CO2 compare to other treatments. Key words : Rice cultivars, Enrichment CO2, C, N, Zn, Mg DOI: 10.3329/bjsir.v44i2.3680 Bangladesh J. Sci. Ind. Res. 44(2), 241-246, 2009   

scholarly journals Effects Of CO2 And Nitrogen Levels On Yield And Yield Attributes Of Rice Cultivars

1970 ◽  
Vol 36 (2) ◽  
pp. 213-221 ◽  
Author(s):  
MA Razzaque ◽  
MM Haque ◽  
QA Khaliq ◽  
ARM Soliman ◽  
A Hamid
Keyword(s):  
Elevated Co2 ◽  
Co2 Enrichment ◽  
Rice Cultivars ◽  
Rice Varieties ◽  
Local Varieties ◽  
Yield Attributes ◽  
Nitrogen Levels ◽  
N Level ◽  
Open Field Condition ◽  
Ambient Co2

A pot experiment was conducted at Bangbandhu Sheikh Mujibur Rahman Agricultural University during July–December of 2003 to determine the effect of rice varieties under CO2 enrichment and different levels of nitrogen supply. Plants were grown from seedling to maturity inside open top chamber under elevated CO2 (570 ±50) ppm, ambient CO2 (~360ppm) and open field condition. Cultivars responded considerably under different nitrogen levels. Increasing atmospheric CO2 directly stimulated photoynthesis and plant growth resulting in increased grain yield. Among the cultivars, BRRIdhan 39 gave the highest yield (50.82 g/plant1) at supra optimum N level and elevated CO2. Local varieties gave similar results under elevated CO2 in optimum and supra optimum N level. The lowest yield was produced by the local variety Shakkorkhora (15.09 g) under ambient CO2 with no nitrogen application. Keywords: CO2 enrichment; nitrogen level; rice cultivars DOI: http://dx.doi.org/10.3329/bjar.v36i2.9247 BJAR 2011; 36(2): 213-221

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