Photosynthesis of wheat under field conditions. V.* The effect of sugar elevation on the distribution of photosynthetic activity within the crop canopy

1972 ◽  
Vol 23 (3) ◽  
pp. 397 ◽  
Author(s):  
DW Puckridge
Keyword(s):  
Photosynthetic Activity ◽  
Specific Activity ◽  
Dry Weight ◽  
Total Carbon ◽  
The Sun ◽  
Crop Canopy ◽  
Carbon Dioxide Uptake ◽  
Assimilation Chamber ◽  
Solar Elevation ◽  
Relative Contribution

The distribution of photosynthetic activity within the canopy of a wheat community was measured at different times of the day Plants In the field were covered by a Perspex assimilation chamber and exposed to 14CO2 and light for 15 min., then harvested and dissected. The relative specific activity and dry weight of the parts, and the calculated total carbon dioxide uptake of the community were then used to determine the distribution of photosynthesis within the community. The contribution of the lower leaves and leaf sheaths increased with increasing elevation of the sun up to 67°, while the photosynthesis of the flag leaves approached a maximum when the elevation of the sun was only 28°. The relative contribution of the ears to total photosynthesis decreased from 33 to 13% as the solar elevation increased from 17 to 67°. __________________ *Part IV, Aust. J. Agric. Res., 22: 1 I (1971).

Photosynthesis of wheat under field conditions. II.* Effect of defoliation on the carbon dioxide uptake of the community

1969 ◽  
Vol 20 (4) ◽  
pp. 623
Author(s):  
DW Puckridge
Keyword(s):  
Carbon Dioxide ◽  
Flag Leaf ◽  
Wheat Plant ◽  
Horizontal Component ◽  
Field Conditions ◽  
The Sun ◽  
Carbon Dioxide Uptake ◽  
Assimilation Chamber ◽  
Before And After

A field assimilation chamber was used to measure the carbon dioxide uptake of wheat plants in the field before and after defoliation or ear removal. At anthesis and 10 days later only the top three leaves were effective in photosynthesis. Removal of the two leaves below the flag leaf reduced photosynthesis of the community by 25–28% and further removal of the flag leaf reduced the community photosynthesis by an additional 24–30%. The estimated contribution of the ears depended on the technique of measurement and varied from 7 to 15%. After removal of the leaf laminae and ears, the stems and leaf sheaths assimilated carbon dioxide at a rate of 44% of that of the whole community. For defoliated plants, photosynthesis of the ears and stems increased with increasing elevation of the sun, which indicated a greater efficiency of photosynthesis with an increased horizontal component of radiation. This was opposite to the response of the undefoliated community. The techniques of estimating the contribution of individual organs to total photosynthesis of the wheat plant are discussed in relation to variability of results and the effects of compensation. * Part I, Aust. J. Agric. Res., 1968, 19: 711.

Photosynthesis of wheat under field conditions. III. Seasonal trends in carbon dioxide uptake of crop communities

1971 ◽  
Vol 22 (1) ◽  
pp. 1 ◽  
Author(s):  
DW Puckridge
Keyword(s):  
Carbon Dioxide ◽  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Weight ◽  
Field Conditions ◽  
Wheat Cultivars ◽  
Area Index ◽  
Carbon Dioxide Uptake ◽  
Assimilation Chamber

Photosynthesis of two wheat cultivars grown in the field was examined during three seasons by use of a portable field assimilation chamber. There were large differences in dry weight, leaf area, and carbon dioxide uptake between seasons. Variations in carbon dioxide uptake by the community were related mainly to changes in leaf area index (LAI). There were changes in carbon dioxide uptake per unit LAI with time, and between the two cultivars in the first season, but the effects of these changes were small compared with the effects of LAI. Differences in grain yield were correlated with LAI and carbon dioxide uptake in the period after anthesis.

Corrigendum - Photosynthesis of wheat under field conditions. II. Effect of defoliation on the carbon dioxide uptake of the community

1969 ◽  
Vol 20 (4) ◽  
pp. 623
Author(s):  
DW Puckridge
Keyword(s):  
Carbon Dioxide ◽  
Flag Leaf ◽  
Wheat Plant ◽  
Horizontal Component ◽  
Field Conditions ◽  
The Sun ◽  
Carbon Dioxide Uptake ◽  
Assimilation Chamber ◽  
Before And After

A field assimilation chamber was used to measure the carbon dioxide uptake of wheat plants in the field before and after defoliation or ear removal. At anthesis and 10 days later only the top three leaves were effective in photosynthesis. Removal of the two leaves below the flag leaf reduced photosynthesis of the community by 25–28% and further removal of the flag leaf reduced the community photosynthesis by an additional 24–30%. The estimated contribution of the ears depended on the technique of measurement and varied from 7 to 15%. After removal of the leaf laminae and ears, the stems and leaf sheaths assimilated carbon dioxide at a rate of 44% of that of the whole community. For defoliated plants, photosynthesis of the ears and stems increased with increasing elevation of the sun, which indicated a greater efficiency of photosynthesis with an increased horizontal component of radiation. This was opposite to the response of the undefoliated community. The techniques of estimating the contribution of individual organs to total photosynthesis of the wheat plant are discussed in relation to variability of results and the effects of compensation.

METHODS OF PROTEIN EXTRACTION FROM NEUROSPORA CRASSA

1964 ◽  
Vol 10 (1) ◽  
pp. 29-35 ◽  
Author(s):  
G. J. Stine ◽  
W. N. Strickland ◽  
R. W. Barratt
Keyword(s):  
Glutamic Acid ◽  
Neurospora Crassa ◽  
Total Protein ◽  
Extraction Method ◽  
Protein Extraction ◽  
Specific Activity ◽  
Dry Weight ◽  
Acid Dehydrogenase ◽  
Total Enzyme

Nine methods for disrupting the mycelium of Neurospora crassa have been compared. Protein percentages are calculated per gram dry weight of mycelium. A TPN-specific glutamic acid dehydrogenase was extracted and the efficiency of each extraction method is given as total enzyme extracted and specific activity. In terms of total protein, total enzyme, and practicality of the method, the Hughes Press, the French Press and the Raper–Hyatt Press were found to be the most efficient. The advantages and limitations of each method are considered.

THE PHYSIOLOGY OF HOST-PARASITE RELATIONS: IX. FURTHER OBSERVATIONS ON THE ACCUMULATION OF RADIOACTIVE SUBSTANCES AT RUST INFECTIONS

1961 ◽  
Vol 39 (6) ◽  
pp. 1393-1407 ◽  
Author(s):  
Michael Shaw
Keyword(s):  
Specific Activity ◽  
Dry Weight ◽  
Insoluble Fraction ◽  
Pentose Phosphate ◽  
Accumulation Ratio ◽  
X Ray ◽  
Specific Activities ◽  
Leaf Segments ◽  
Wheat Leaves ◽  
Host Parasite

Wang (Can. J. Botany, 38, 635–642 (1960)) concluded that the accumulation of radioactivity observed on radioautographs at infection sites on rusted leaves fed with C14-labelled substances was 'apparent' rather than real. The ‘accumulation ratio’ is defined as the ratio of the specific activities (c.p.m./mg dry weight of intact tissue) of rust-infected to uninfected areas of infected leaves. Theoretical considerations relating to the radioautography of leaves labelled with C14 and to the measurement of ‘accumulation ratios’ by extraction of C14-labelled substances from rusted and uninfected segments of infected leaves, as well as experimental data, show that Wang's conclusion is not generally applicable.Experimentally, it was shown using polymethacrylate C14 sources that differences in distance between sources and X-ray film of the order of 100 μ had no effect on the intensity of autoradiographs. Rust-infected leaves, fed with radioactive glucose, were radiographed between X-ray plates. Localization of radioactivity at infection sites was observed on both ‘dorsal’ and ‘ventral’ radiographs, indicating a real accumulation per unit area. Ventral were more radioactive than dorsal surfaces. The main development of the fungus occurred on the former. Radioautography revealed that C14 from glucose-1-C14, glucose-6-C14, and uniformly labelled glucose fed to excised wheat leaves became localized at 10-day-old rust infections in 2 hours. ‘Accumulation ratios’ calculated from the specific activity of leaf segments remained close to 1.0 for at least 6 hours after introduction of the tracer, but increased to more than 2 after 24 hours. When ‘accumulation ratios’ were calculated from the specific activities of individual pustules (excised with a punch 1 mm in diameter) and interpustular disks, values greater than 1 were observed in 2 hours, thus confirming the results of autoradiography. Differences between the ‘accumulation ratios’ observed with glucose-6-C14 and glucose-1-C14 were consistent with an increased role of the pentose phosphate pathway at infection sites. Incorporation of C14 from uniformly labelled glucose into the alcohol-insoluble fraction of rusted leaf segments was 2.5-fold that in uninfected segments in 6 hours and 3.65-fold in 24 hours. The humin formed during hydrochloric acid hydrolysis accounted for approximately 50% of the activity of the alcohol-insoluble material. The ‘accumulation ratio’ for the alcohol-soluble material was only 1.56 after 24 hours.All the results support the view (Shaw and Samborski, Can. J. Botany, 34, 389–405 (1956)) that there is a quantitative, metabolically dependent accumulation of C14 from radioactive glucose at vigorous rust infections. The relative roles of fungus and host in this process are discussed briefly.

scholarly journals Phytodepuration of Nitrate Contaminated Water Using Four Different Tree Species

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 515
Author(s):  
Luca Regni ◽  
Maria Luce Bartucca ◽  
Euro Pannacci ◽  
Francesco Tei ◽  
Daniele Del Buono ◽  
...  
Keyword(s):  
Tree Species ◽  
Photosynthetic Activity ◽  
Dry Weight ◽  
Contaminated Water ◽  
Buffer Strips ◽  
Sambucus Nigra ◽  
Salix Alba ◽  
Global Issue ◽  
Corylus Avellana L ◽  
Agricultural Areas

Water pollution by excessive amounts of nitrate (NO3−) has become a global issue. Technologies to clean up nitrate-contaminated water bodies include phytoremediation. In this context, this research aimed to evaluate four tree species (Salix alba L., Populus alba L., Corylus avellana L. and Sambucus nigra L.) to remediate nitrate-contaminated waters (100 and 300 mg L−1). Some physiological parameters showed that S. alba L. and P. alba L. increased particularly photosynthetic activity, chlorophyll content, dry weight, and transpired water, following the treatments with the above NO3− concentrations. Furthermore, these species were more efficient than the others studied in the phytodepuration of water contaminated by the two NO3− levels. In particular, within 15 days of treatment, S. alba L. and P. alba L. removed nitrate quantities ranging from 39 to 78%. Differently, C. avellana L. and S. nigra L. did not show particular responses regarding the physiological traits studied. Nonetheless, these species removed up to 30% of nitrate from water. In conclusion, these data provide exciting indications on the chance of using S. alba L. and P. alba L. to populate buffer strips to avoid NO3− environmental dispersion in agricultural areas.

scholarly journals The role of methanotrophy in the microbial carbon metabolism of temperate lakes

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Paula C. J. Reis ◽  
Shoji D. Thottathil ◽  
Yves T. Prairie
Keyword(s):  
Water Column ◽  
Carbon Metabolism ◽  
Volume Fraction ◽  
Specific Activity ◽  
Freshwater Ecosystems ◽  
Carbon Consumption ◽  
Temperate Lakes ◽  
Relative Contribution ◽  
Methane Oxidizing Bacteria ◽  
Microbial Carbon

AbstractPrevious stable isotope and biomarker evidence has indicated that methanotrophy is an important pathway in the microbial loop of freshwater ecosystems, despite the low cell abundance of methane-oxidizing bacteria (MOB) and the low methane concentrations relative to the more abundant dissolved organic carbon (DOC). However, quantitative estimations of the relative contribution of methanotrophy to the microbial carbon metabolism of lakes are scarce, and the mechanism allowing methanotrophy to be of comparable importance to DOC-consuming heterotrophy remained elusive. Using incubation experiments, microscopy, and multiple water column profiles in six temperate lakes, we show that MOB play a much larger role than their abundances alone suggest because of their larger cell size and higher specific activity. MOB activity is tightly constrained by the local methane:oxygen ratio, with DOC-rich lakes with large hypolimnetic volume fraction showing a higher carbon consumption through methanotrophy than heterotrophy at the whole water column level. Our findings suggest that methanotrophy could be a critical microbial carbon consumption pathway in many temperate lakes, challenging the prevailing view of a DOC-centric microbial metabolism in these ecosystems.

scholarly journals Allometric equation of local bamboo for estimating carbon sequestration of bamboo riparian forest

2021 ◽  
Vol 905 (1) ◽  
pp. 012002
Author(s):  
C Prayogo ◽  
C Muthahar ◽  
R M Ishaq
Keyword(s):  
Land Use ◽  
Carbon Sequestration ◽  
Riparian Forest ◽  
Dry Weight ◽  
Allometric Equation ◽  
Total Carbon ◽  
Destructive Sampling ◽  
Industrial Activities ◽  
Bamboo Stem ◽  
The Relationship

Abstract The cause of global warming is the increasing carbon concentration arising from industrial activities, burning of fossils, and land-use change. The purpose of this research was to find out the allometric equation to calculate the local bamboo biomass and then to be able to calculate how much carbon sequestration at bamboo riparian forest since this area was rarely being explored. The parameters observed were the height and diameter of the bamboo stem at 1.3 m height of 6 types of local bamboo using destructive sampling, along with the measurement of bamboo weight. The carbon content of the bamboo biomass, litter, and soil was measured to complement the estimation of total carbon sequestration. The results showed that the allometric equation for estimating local bamboo biomass is Y=0.6396 X1.6162 with R2=0.77, obtained from the relationship equations between dry weight and the diameter. Total carbon sequestration of this system ranged between 81 to 215 tons C ha−1.

scholarly journals In Situ Estimation of Carbon Balance of In Vitro Sweetpotato and Tomato Plantlets Cultured with Varying Initial Sucrose Concentrations in the Medium

2002 ◽  
Vol 127 (6) ◽  
pp. 963-970 ◽  
Author(s):  
Chieri Kubota ◽  
Makiko Ezawa ◽  
Toyoki Kozai ◽  
Sandra B. Wilson
Keyword(s):  
Carbon Balance ◽  
Ipomoea Batatas ◽  
Dry Weight ◽  
Photon Flux ◽  
Sugar Uptake ◽  
Relative Contribution ◽  
Carbon Balances ◽  
Species Specific

The effects of initial sucrose (suc) concentrations in the medium (S0) on the carbon balance and growth of sweetpotato [Ipomoea batatas (L.) Lam. `Beniazuma'] and tomato (Lycopersicon esculentum Mill. `HanaQueen') plantlets were studied under controlled environmental conditions. Plantlets were cultured with 0, 7.5, 15, or 30 g·L-1 of S0 under high photosynthetic photon flux (160 to 200 μmol·m-2·s-1) and CO2 enriched (1400 to 2050 μmol·mol-1) conditions. Net photosynthetic rate per leaf area (Pl) decreased and dry weight per plantlet (Wd) increased with increasing S0, but did not differ significantly between S0 of 7.5 to 30 g·L-1 for sweetpotato or 15 to 30 g·L-1 for tomato. Carbon influxes and effluxes of the plantlets by metabolism of medium suc and/or photosynthesis, and respiration were estimated based on measurements of in situ and steady state CO2 exchange rates and sugar uptake during culture. At S0 from 7.5 to 30 g·L-1, photosynthesis was responsible for 82% to 92% and 60% to 67% of carbohydrate assimilation for sweetpotato and tomato, respectively. Estimated carbon balances of plantlets based on the estimated and actual increases of moles of carbon in plant tissue demonstrated that in situ estimation of carbon balance was reasonably accurate for sweetpotato at S0 of 0 to 15 g·L-1 and for tomato at S0 of 0 g·L-1 and that the actual contribution of photosynthesis for tomato at high S0 might be lower than the values estimated in the present experiment. Results showed that initial suc concentration affected the relative contribution of photosynthesis on their carbon balances and that the responses were species specific. The failure of validation at S0 in a range specific to each species suggested the need for further study on carbon metabolism of in vitro plantlets cultured with sugar in the medium.

PROPERTIES OF BOVINE Ac-GLOBULIN CONCENTRATES AND METHODS OF PREPARATION

1963 ◽  
Vol 41 (1) ◽  
pp. 2409-2421 ◽  
Author(s):  
Nobuo Aoki ◽  
Charles R. Harmison ◽  
Walter H. Seegers
Keyword(s):  
Human Plasma ◽  
Ammonium Sulphate ◽  
Protein Concentration ◽  
Room Temperature ◽  
Specific Activity ◽  
Barium Carbonate ◽  
Dry Weight ◽  
Physical Chemical ◽  
Bovine Plasma ◽  
Refrigerator Temperature

A procedure is described for retaining bovine plasma Ac-globulin activity as one part of the protein from plasma for every 1000 parts removed. The yields averaged 15%. The procedure involves removal of prothrombin with barium carbonate, isoelectric fractionation, fractionation with ammonium sulphate, chromatography on Amberlite IRC-50, and a second fractionation with ammonium sulphate. The procedure requires 2 days; however, the first day completes up to chromatography and the concentrate at that time is quite useful for many purposes. It is more stable than the product obtained after chromatography and the yields are higher. In absence of salts Ac-globulin is quite insoluble at pH 5.0. The final product usually contained some impurity. With the analytical ultra-centrifuge the S20in 0.1 M potassium chloride solution was found to be 4.2 at a protein concentration of 12.4 mg/ml. The specific activity was 1500 U./mg dry weight. Bovine plasma contains 120 U./ml or about 9 mg/100 ml. Assuming the same specific activity for human plasma the concentration is most likely near 1 mg/100 ml. The best stability conditions found were: 50% glycerol, pH 7.0, and 0.1 M calcium chloride. Under those conditions at room temperature all activity was retained 6 to 7 hours, at refrigerator temperature 24 hours, and at −60 °C for 1 month. In rabbits, antibodies were readily produced. Oxidizing agents destroyed the activity, while reducing agents did not, nor did they tend to stabilize. SH blocking agents destroyed the activity. The loss of activity in the presence of 0.0025 M parachloromercuribenzoate was recovered with 0.04 M cysteine. The molecule deteriorated while attempts were made to obtain physical chemical data; consequently, the molecular weight was calculated from an amino acid analysis and found to be 98,800. The reliability of this value is problematical. Human plasma was analyzed and found to contain 13 U./ml Ac-globulin. After 4 days storage, at room temperature, the prolonged prothrombin time of that plasma was completely restored with 13 units of Ac-globulin, which is equivalent to 8 μg.

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