John Troughton - Academia.edu (original) (raw)

Papers by John Troughton

Research paper thumbnail of Seasonal variations of carbon isotope fractionation in crassulacean acid metabolism plants

Research paper thumbnail of Phyciological and biochemical characteristics of C3 and C4 Atriplex species and hybrids in relation to the evolution of the C4 pathway

Research paper thumbnail of Seasonal effects on carbon isotope composition of cactus in a desert environment

Research paper thumbnail of Photosynthetic pathways and carbon isotope discrimination by plants

Research paper thumbnail of Plant Physiology: Phloem Translocation . M. J. Canny. Cambridge University Press, New York, 1973. xii, 302 pp., illus. + plates. $22.50

Research paper thumbnail of δ13C as an Indicator of Carboxylation Reactions

Springer eBooks, 1979

The nomenclature δ13C describes quantitatively the phenomenon of fractionation of carbon isotopes... more The nomenclature δ13C describes quantitatively the phenomenon of fractionation of carbon isotopes. Discrimination between isotopes emphasizes the differences in thermodynamic and kinetic properties of the isotopic species and generally assumes the chemical behavior of the species is similar. Urey (1947) advanced the theory of isotope fractionation in a paper on the thermodynamic properties of isotopic substances, and this work predicted that fractionation would occur between the two stable isotopes of carbon, 12C and 13C. Atmospheric CO2 is a mixture of the stable isotopes 12O 16O 16O, 13C 16O 16O and 12C 18O 18O and fractionation between the stable carbon isotopes can be expected during the assimilation of CO2 in photosynthesis.

Research paper thumbnail of Photosynthetic Pathways in Plants of Coastal and Inland Habitats of Israel and the Sinai1)1) Part of the investigations were carried out by one of us (K.W.) at the Avdat Experimental Station, Negev, Israel, with the generous cooperation of Prof. Dr. M. Evenari

Research paper thumbnail of Regulation of carbon dioxide exchange in plants

Research paper thumbnail of 1224 From John Troughton Clapham, Surrey, 12 March 1690/1

Calendar of the Correspondence of Richard Baxter, Vol. 2: 1660–1696, 1991

Research paper thumbnail of Translocation in Zea mays Leaves

Research paper thumbnail of Calendar of the Correspondence of Richard Baxter, vol. 1, 1638–1660; vol. 2, 1660–1696. Edited by N. H. Keeble and Geoffrey F. Nuttall. Oxford: Clarendon Press, 1991. xl + 443, 387 pp. <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mn>95.00</mn><mo separator="true">,</mo></mrow><annotation encoding="application/x-tex">95.00, </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8389em;vertical-align:-0.1944em;"></span><span class="mord">95.00</span><span class="mpunct">,</span></span></span></span>89.00

Research paper thumbnail of Scanning electron microscopic obser vations of pollen grains and stigma in the self-incompatible heteromorphic species Primula malacoides Franch. and Forsythia x intermedia Zab., and genetics of sporopollenin deposition

Euphytica, Jun 1, 1974

SummaryScanning electron microscopic observations revealed differences in surface morphology and ... more SummaryScanning electron microscopic observations revealed differences in surface morphology and size of stigmatic papillae and pollen grains in the two forms of flower of the dimorphic species Primula malacoides and Forsythia x intermedia. In P. malacoides pin papillae are longer and have more inflated globose tips than those of the thrum form which have oval tips, and the larger thrum pollen grain has a rougher form of exine sculturing than pin pollen grain. The correspondence of exine pattern dimorphism with the dimorphism of floral form associated with the sporophytically controlled incompatibility system, indicates that the control of sporopollenin deposition is also sporophytically determined.Scanning electron microscope observations have also been made of pollen grain-stigma interactions in compatible and incompatible pollinations.Recent literature on the control of sporopollenin deposition is briefly discussed. It is concluded that the extent of deposition of the sporopollenin is controlled by the meiocytes but the actual template determination is controlled by the tapetal material, and much, if not all, of the sporopollenin itself may be synthesized in, and derived from, the tapetum.

Research paper thumbnail of Growth responses of plants from habitats with contrasting thermal environments--transplant studies in the Death Valley and Bodega Head experimental gardens

Research paper thumbnail of Physiological Ecology of CO2 Fixation in Bromeliaceae

Flora, 1977

Crassulacean acid metabolism is widely distributed among Bromeliaceae. Gas chromatographic analys... more Crassulacean acid metabolism is widely distributed among Bromeliaceae. Gas chromatographic analyses of cell sap extracted at the beginning and the end of the light period showed that malate is responsible for above 70 % of the acidity changes. Simultaneous concentration changes in other acids were detected but their significance is not clear. Environmental control of CAM is showed for nutrient supply, temperature and water supply. In natural conditions within the same altitudinal belt, nitrogen content (and probably chlorophyll as a consequence) seems to be positively correlated with CAM activity. Temperature dependence of CO2 exchange shows that there is a temperature optimum near 15°C. Water supply restriction induces CAM CO2 exchange patterns in Guzmania monostachia while reduces net CO 2 gain in Tillandsia utriculata. G. monostachia is considered an intermediate species, and is postulated that the bromelioid species Wittrockia campos-portoi and Nidularium innocentii var. innocentii (based on t5'3C rations) should behave in a similar way. The ecological and evolutionary relevance of borde-line species seems to be that they represent the linkage between arid and humid habitats in the differentiation of the family. Finally it is shown that t5'3C ratios present a continuous spectrum in the family as a result of environmentally controlled CAM activity in many species and the differentiation of typical 3C and CAM species adapted to extreme humid and shady or arid environments respectively.

Research paper thumbnail of Photosynthetic Mechanisms and Paleoecology from Carbon Isotope Ratios in Ancient Specimens of C 4 and CAM Plants

Science, 1974

Carbon istotope ratios of modern, 10,000-year-old, and more than 40,000-year-old Atriplex confert... more Carbon istotope ratios of modern, 10,000-year-old, and more than 40,000-year-old Atriplex confertifolia (C(4)) material from Nevada caves indicate that the C(4) photosynthetic pathway was operating in these plants over that period. Samples of a plant with crassulacean acid metabolism, Opuntia polyacantha, were also measured, and a shift in the 8(13)C value from -21.9 per mil (more than 40,000 years ago) to -13.9 per mil (10,000 years ago) was observed. This provides unique physiological evidence to support the hypothesis that the late Pleistocene pluvial climate in the region already had become drier about 10,000 years ago.

Research paper thumbnail of Non-Existence of an Optimum Leaf Area Index for the Production Rate of White Clover Grown Under Constant Conditions

Research paper thumbnail of Carbon Isotope Discrimination in Photosynthesis of CAM Plants

Research paper thumbnail of Differences in natural carbon isotope ratios of milk and hair from cattle grazing tropical and temperate pastures

Research paper thumbnail of Prediction of Growth Rate at Different Light Levels from Measured Photosynthesis and Respiration Rates

Plant Physiology, 1966

Light integrators with a linlear responise are not suitable for measurinig the light climates of ... more Light integrators with a linlear responise are not suitable for measurinig the light climates of plants because plants are not linear integrators. It should be possible to make a quantitative allowanice for this nonlinearity by using the C,O, uptake curve of the plant. To test this, we have subjected white clover plants to different levels of constanit light, comqparing the rate of increase of total dry matter with the net rate of uptake of CO. per day. Tenmperature, humidity, daylength and nutrient supply were kept coinstanlt. The growtth rate calculated from CO, uptake agreed well with the observed rate over the light levels tested (3.7-88 wm-2, 0.4-0.7 micron : 1 w m-2 = 103 ergsec-'mC-2). All plants put on weight over the few days of the experiment, even those)laced at light levels below their compensation point. The plants adapted their respirationi rates to he a conistant proportion of their growth rates. Most of the adaptationi occurred within 24 hours of the light change. The a(laptation of respiration has implications for miiodels of light/growth relations in plant communities, almost all of whichi assume that respiration is proportional to leaf area and(independenit of growth rate or light level. The onily miiodel which does not is that of (le WVit, and(this gave good agreemiienit with ouir results. In order to he able to predict the influence of light on the rate of growth of a plant, one must measure the light in a way which is meaningful to the plant. Since l)lants are nonlinear devices, the rea(liilgs of a liniear light integrator are not meaninigfutl in this sense (10). In principle. one could use the CO.,-uptake curve of the planit to predict growth rate froml light. T'he present experiment was designe(l to test this princil)le, iuni(ler the simplest possible coni(litionis. Materials and Methods Pla(11t .lIatcrioil (id Grolztl C(on ditionis. The material ulse(l wN,as Trifoliitm rcpcns L., Grassland(s D)ivision Ntucleus N.Z. White Clover C 1852 1962/3. The planits were grow%n in controlled-environment cabinets, at conistanit temperature, humidlity, daylength anid niutrien-t supply (20 + 1°, 85 + 5 % R.H., 12hour (lay, Hoagland-type nutrienit in Perlite). The cabinets were lit from above with a bank of mercury-tungsten reflector lamps, a water filter being used to remove heat radiation, the irradiance within the wavelengths 0.4 anid 0.7 micron, in units of w*m-'. For reasoins given elsewhere (11), the irradiance is the quantity which is more meaningful to the plant. A conversion factor of 35 X 10-3, appropriate for this type of lanip, was applied to convert illumination in ft-c to irradiance 559 41 No. 4 ril 1966

Research paper thumbnail of Probing plant structure;: A scanning electron microscope study of some anatomical features in plants and the relationship of these structures to physiological processes

probing plant structure a scanning electron microscope homework answers modern chemistry wmppg in... more probing plant structure a scanning electron microscope homework answers modern chemistry wmppg in the season of sun mrvisa de amsterdamse school architecture project sqlman geometry surface area volume quiz answers freshu psychology in the new millennium webinn class a weighted composition operators report lifetime encyclopedia of letters screes arctic son fulfilling the dream expedition series political economy for the people loobys azerbaijan a quest for identity tformc the private affairs of bel ami odawa things that happen because they should a teleological classical readings in african library development 2000 nissan sentra manual bidel all beautiful things luggo perkins 3003 engine repair manual jbstv cautio criminalis or a book on witch trials seses fbla internet scavenger hunt answers sheet screes lettres de m mesmer messieurs les auteurs du journal de paris cuando las parejas oran when couples pray tvdocs cooking without frontiers an international cookbook monster in the la...

Research paper thumbnail of Seasonal variations of carbon isotope fractionation in crassulacean acid metabolism plants

Research paper thumbnail of Phyciological and biochemical characteristics of C3 and C4 Atriplex species and hybrids in relation to the evolution of the C4 pathway

Research paper thumbnail of Seasonal effects on carbon isotope composition of cactus in a desert environment

Research paper thumbnail of Photosynthetic pathways and carbon isotope discrimination by plants

Research paper thumbnail of Plant Physiology: Phloem Translocation . M. J. Canny. Cambridge University Press, New York, 1973. xii, 302 pp., illus. + plates. $22.50

Research paper thumbnail of δ13C as an Indicator of Carboxylation Reactions

Springer eBooks, 1979

The nomenclature δ13C describes quantitatively the phenomenon of fractionation of carbon isotopes... more The nomenclature δ13C describes quantitatively the phenomenon of fractionation of carbon isotopes. Discrimination between isotopes emphasizes the differences in thermodynamic and kinetic properties of the isotopic species and generally assumes the chemical behavior of the species is similar. Urey (1947) advanced the theory of isotope fractionation in a paper on the thermodynamic properties of isotopic substances, and this work predicted that fractionation would occur between the two stable isotopes of carbon, 12C and 13C. Atmospheric CO2 is a mixture of the stable isotopes 12O 16O 16O, 13C 16O 16O and 12C 18O 18O and fractionation between the stable carbon isotopes can be expected during the assimilation of CO2 in photosynthesis.

Research paper thumbnail of Photosynthetic Pathways in Plants of Coastal and Inland Habitats of Israel and the Sinai1)1) Part of the investigations were carried out by one of us (K.W.) at the Avdat Experimental Station, Negev, Israel, with the generous cooperation of Prof. Dr. M. Evenari

Research paper thumbnail of Regulation of carbon dioxide exchange in plants

Research paper thumbnail of 1224 From John Troughton Clapham, Surrey, 12 March 1690/1

Calendar of the Correspondence of Richard Baxter, Vol. 2: 1660–1696, 1991

Research paper thumbnail of Translocation in Zea mays Leaves

Research paper thumbnail of Calendar of the Correspondence of Richard Baxter, vol. 1, 1638–1660; vol. 2, 1660–1696. Edited by N. H. Keeble and Geoffrey F. Nuttall. Oxford: Clarendon Press, 1991. xl + 443, 387 pp. <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mn>95.00</mn><mo separator="true">,</mo></mrow><annotation encoding="application/x-tex">95.00, </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8389em;vertical-align:-0.1944em;"></span><span class="mord">95.00</span><span class="mpunct">,</span></span></span></span>89.00

Research paper thumbnail of Scanning electron microscopic obser vations of pollen grains and stigma in the self-incompatible heteromorphic species Primula malacoides Franch. and Forsythia x intermedia Zab., and genetics of sporopollenin deposition

Euphytica, Jun 1, 1974

SummaryScanning electron microscopic observations revealed differences in surface morphology and ... more SummaryScanning electron microscopic observations revealed differences in surface morphology and size of stigmatic papillae and pollen grains in the two forms of flower of the dimorphic species Primula malacoides and Forsythia x intermedia. In P. malacoides pin papillae are longer and have more inflated globose tips than those of the thrum form which have oval tips, and the larger thrum pollen grain has a rougher form of exine sculturing than pin pollen grain. The correspondence of exine pattern dimorphism with the dimorphism of floral form associated with the sporophytically controlled incompatibility system, indicates that the control of sporopollenin deposition is also sporophytically determined.Scanning electron microscope observations have also been made of pollen grain-stigma interactions in compatible and incompatible pollinations.Recent literature on the control of sporopollenin deposition is briefly discussed. It is concluded that the extent of deposition of the sporopollenin is controlled by the meiocytes but the actual template determination is controlled by the tapetal material, and much, if not all, of the sporopollenin itself may be synthesized in, and derived from, the tapetum.

Research paper thumbnail of Growth responses of plants from habitats with contrasting thermal environments--transplant studies in the Death Valley and Bodega Head experimental gardens

Research paper thumbnail of Physiological Ecology of CO2 Fixation in Bromeliaceae

Flora, 1977

Crassulacean acid metabolism is widely distributed among Bromeliaceae. Gas chromatographic analys... more Crassulacean acid metabolism is widely distributed among Bromeliaceae. Gas chromatographic analyses of cell sap extracted at the beginning and the end of the light period showed that malate is responsible for above 70 % of the acidity changes. Simultaneous concentration changes in other acids were detected but their significance is not clear. Environmental control of CAM is showed for nutrient supply, temperature and water supply. In natural conditions within the same altitudinal belt, nitrogen content (and probably chlorophyll as a consequence) seems to be positively correlated with CAM activity. Temperature dependence of CO2 exchange shows that there is a temperature optimum near 15°C. Water supply restriction induces CAM CO2 exchange patterns in Guzmania monostachia while reduces net CO 2 gain in Tillandsia utriculata. G. monostachia is considered an intermediate species, and is postulated that the bromelioid species Wittrockia campos-portoi and Nidularium innocentii var. innocentii (based on t5'3C rations) should behave in a similar way. The ecological and evolutionary relevance of borde-line species seems to be that they represent the linkage between arid and humid habitats in the differentiation of the family. Finally it is shown that t5'3C ratios present a continuous spectrum in the family as a result of environmentally controlled CAM activity in many species and the differentiation of typical 3C and CAM species adapted to extreme humid and shady or arid environments respectively.

Research paper thumbnail of Photosynthetic Mechanisms and Paleoecology from Carbon Isotope Ratios in Ancient Specimens of C 4 and CAM Plants

Science, 1974

Carbon istotope ratios of modern, 10,000-year-old, and more than 40,000-year-old Atriplex confert... more Carbon istotope ratios of modern, 10,000-year-old, and more than 40,000-year-old Atriplex confertifolia (C(4)) material from Nevada caves indicate that the C(4) photosynthetic pathway was operating in these plants over that period. Samples of a plant with crassulacean acid metabolism, Opuntia polyacantha, were also measured, and a shift in the 8(13)C value from -21.9 per mil (more than 40,000 years ago) to -13.9 per mil (10,000 years ago) was observed. This provides unique physiological evidence to support the hypothesis that the late Pleistocene pluvial climate in the region already had become drier about 10,000 years ago.

Research paper thumbnail of Non-Existence of an Optimum Leaf Area Index for the Production Rate of White Clover Grown Under Constant Conditions

Research paper thumbnail of Carbon Isotope Discrimination in Photosynthesis of CAM Plants

Research paper thumbnail of Differences in natural carbon isotope ratios of milk and hair from cattle grazing tropical and temperate pastures

Research paper thumbnail of Prediction of Growth Rate at Different Light Levels from Measured Photosynthesis and Respiration Rates

Plant Physiology, 1966

Light integrators with a linlear responise are not suitable for measurinig the light climates of ... more Light integrators with a linlear responise are not suitable for measurinig the light climates of plants because plants are not linear integrators. It should be possible to make a quantitative allowanice for this nonlinearity by using the C,O, uptake curve of the plant. To test this, we have subjected white clover plants to different levels of constanit light, comqparing the rate of increase of total dry matter with the net rate of uptake of CO. per day. Tenmperature, humidity, daylength and nutrient supply were kept coinstanlt. The growtth rate calculated from CO, uptake agreed well with the observed rate over the light levels tested (3.7-88 wm-2, 0.4-0.7 micron : 1 w m-2 = 103 ergsec-'mC-2). All plants put on weight over the few days of the experiment, even those)laced at light levels below their compensation point. The plants adapted their respirationi rates to he a conistant proportion of their growth rates. Most of the adaptationi occurred within 24 hours of the light change. The a(laptation of respiration has implications for miiodels of light/growth relations in plant communities, almost all of whichi assume that respiration is proportional to leaf area and(independenit of growth rate or light level. The onily miiodel which does not is that of (le WVit, and(this gave good agreemiienit with ouir results. In order to he able to predict the influence of light on the rate of growth of a plant, one must measure the light in a way which is meaningful to the plant. Since l)lants are nonlinear devices, the rea(liilgs of a liniear light integrator are not meaninigfutl in this sense (10). In principle. one could use the CO.,-uptake curve of the planit to predict growth rate froml light. T'he present experiment was designe(l to test this princil)le, iuni(ler the simplest possible coni(litionis. Materials and Methods Pla(11t .lIatcrioil (id Grolztl C(on ditionis. The material ulse(l wN,as Trifoliitm rcpcns L., Grassland(s D)ivision Ntucleus N.Z. White Clover C 1852 1962/3. The planits were grow%n in controlled-environment cabinets, at conistanit temperature, humidlity, daylength anid niutrien-t supply (20 + 1°, 85 + 5 % R.H., 12hour (lay, Hoagland-type nutrienit in Perlite). The cabinets were lit from above with a bank of mercury-tungsten reflector lamps, a water filter being used to remove heat radiation, the irradiance within the wavelengths 0.4 anid 0.7 micron, in units of w*m-'. For reasoins given elsewhere (11), the irradiance is the quantity which is more meaningful to the plant. A conversion factor of 35 X 10-3, appropriate for this type of lanip, was applied to convert illumination in ft-c to irradiance 559 41 No. 4 ril 1966

Research paper thumbnail of Probing plant structure;: A scanning electron microscope study of some anatomical features in plants and the relationship of these structures to physiological processes

probing plant structure a scanning electron microscope homework answers modern chemistry wmppg in... more probing plant structure a scanning electron microscope homework answers modern chemistry wmppg in the season of sun mrvisa de amsterdamse school architecture project sqlman geometry surface area volume quiz answers freshu psychology in the new millennium webinn class a weighted composition operators report lifetime encyclopedia of letters screes arctic son fulfilling the dream expedition series political economy for the people loobys azerbaijan a quest for identity tformc the private affairs of bel ami odawa things that happen because they should a teleological classical readings in african library development 2000 nissan sentra manual bidel all beautiful things luggo perkins 3003 engine repair manual jbstv cautio criminalis or a book on witch trials seses fbla internet scavenger hunt answers sheet screes lettres de m mesmer messieurs les auteurs du journal de paris cuando las parejas oran when couples pray tvdocs cooking without frontiers an international cookbook monster in the la...