Carbon gain, allocation and storage in rhizomes in response to elevated atmospheric carbon dioxide and nutrient supply in a perennial C3 grass, Phalaris arundinacea

2011 ◽  
Vol 38 (10) ◽  
pp. 797 ◽  
Author(s):  
Hannah Kinmonth-Schultz ◽  
Soo-Hyung Kim
Keyword(s):  
Elevated Co2 ◽  
Carbon Allocation ◽  
Photosynthetic Apparatus ◽  
Co2 Assimilation ◽  
Nutrient Supply ◽  
Phalaris Arundinacea ◽  
Carbon Gain ◽  
Bioenergy Feedstock ◽  
Whole Plant ◽  
Productivity And Competitiveness

Reed canary grass (Phalaris arundinacea L.) is a fast-growing, perennial, rhizomatous C3 grass considered as a model invasive species for its aggressive behaviour. The same traits make it a candidate for bioenergy feedstock. We tested the following hypotheses: (1) elevated atmospheric [CO2] and nutrient supply enhance photosynthetic carbon acquisition of this fructan-accumulating grass with little or no photosynthetic downregulation; (2) elevated [CO2] promotes carbon allocation to growth when nutrients are sufficient and to fructan storage in rhizomes when nutrients are low. Plants were grown at ambient or elevated (+320 μmol mol–1) [CO2], and fertilised using full or one-eighth strength modified Hoagland solution. We investigated leaf photosynthesis, whole-plant water use, biomass allocation, and nitrogen and carbon storage in rhizomes. Elevated [CO2] enhanced light-saturated net CO2 assimilation by 61%. It doubled whole-plant, stem and root biomass in summer. Plants grown in elevated [CO2] had a greater rate of CO2 assimilation at higher [CO2], indicating a shift in photosynthetic apparatus for enhanced carbon gain under elevated [CO2]. The majority of belowground biomass was allocated to rhizomes for storage rather than to roots in both seasons. In autumn, elevated [CO2] increased fructan concentration in rhizomes from 8.1 to 11.7% of biomass when nutrients were low (P = 0.023). Our results suggest that elevated [CO2] combined with sufficient nutrients is likely to enhance carbon gain and growth of P. arundinacea, and to increase its productivity and competitiveness in summer. Elevated [CO2] is likely to enhance long-term fructan storage in rhizomes, which may benefit overwintering and vegetative spread.

scholarly journals Net Carbon Gain and Growth of Bell Peppers, Capsicum annuum ‘Cubico’, Following Root Infection by Pythium aphanidermatum

2005 ◽  
Vol 95 (4) ◽  
pp. 354-361 ◽  
Author(s):  
M. Johnstone ◽  
S. Chatterton ◽  
J. C. Sutton ◽  
B. Grodzinski
Keyword(s):  
Leaf Area ◽  
Capsicum Annuum ◽  
Photosynthetic Apparatus ◽  
Pythium Aphanidermatum ◽  
Root Disease ◽  
Carbon Accumulation ◽  
Total Carbon ◽  
Carbon Gain ◽  
Whole Plant ◽  
Bell Peppers

The first characterization of alterations in whole-plant photosynthetic rate and carbon assimilation of bell peppers associated with infection by Pythium aphanidermatum is described. Relationships of root disease caused by P. aphanidermatum to whole-plant net carbon exchange rate (NCER), total carbon accumulation, dark respiration rates, water loss, and destructive growth parameters were quantified in vegetative, hydroponically grown pepper plants (Capsicum annuum ‘Cubico’). Inoculated plants displayed lower whole-plant NCER. This translated into a loss of 28% in cumulative C gain during 7 days after inoculation and occurred before visible shoot symptoms developed. Leaf area and dry weight of shoots and roots were significantly decreased and the shoot/root ratio was higher in inoculated plants than in noninoculated plants. We propose that reduced NCER in inoculated plants was mainly due to restricted development of leaf area, because no differences in NCER and evapotranspiration were observed between control and inoculated plants when expressed based on leaf area and root dry mass, respectively. These findings indicate that Pythium infection did not affect the photosynthetic apparatus directly and that the reductions in photosynthesis and growth were not caused by inefficient water transport by diseased roots. These results enlarge on the understanding of physiological responses of host plants to early stages of root disease.

scholarly journals Environmental effects on photosynthetic capacity of bean genotypes

2004 ◽  
Vol 39 (7) ◽  
pp. 615-623 ◽  
Author(s):  
Rafael Vasconcelos Ribeiro ◽  
Mauro Guida dos Santos ◽  
Gustavo Maia Souza ◽  
Eduardo Caruso Machado ◽  
Ricardo Ferraz de Oliveira ◽  
...  
Keyword(s):  
High Temperature ◽  
Natural Condition ◽  
Temperature Effects ◽  
Environmental Changes ◽  
Photosynthetic Capacity ◽  
Photosynthetic Apparatus ◽  
Co2 Assimilation ◽  
Fluorescence Yield ◽  
Environmental Condition ◽  
Response Curves

Photosynthetic responses to daily environmental changes were studied in bean (Phaseolus vulgaris L.) genotypes 'Carioca', 'Ouro Negro', and Guarumbé. Light response curves of CO2 assimilation and stomatal conductance (g s) were also evaluated under controlled (optimum) environmental condition. Under this condition, CO2 assimilation of 'Carioca' was not saturated at 2,000 µmol m-2 s-1, whereas Guarumbé and 'Ouro Negro' exhibited different levels of light saturation. All genotypes showed dynamic photoinhibition and reversible increase in the minimum chlorophyll fluorescence yield under natural condition, as well as lower photosynthetic capacity when compared with optimum environmental condition. Since differences in g s were not observed between natural and controlled conditions for Guarumbé and 'Ouro Negro', the lower photosynthetic capacity of these genotypes under natural condition seems to be caused by high temperature effects on biochemical reactions, as suggested by increased alternative electron sinks. The highest g s values of 'Carioca' were observed at controlled condition, providing evidences that reduction of photosynthetic capacity at natural condition was due to low g s in addition to the high temperature effects on the photosynthetic apparatus. 'Carioca' exhibited the highest photosynthetic rates under optimum environmental condition, and was more affected by daily changes of air temperature and leaf-to-air vapor pressure difference.

CO2 × Nitrogen Interaction on Seedling Growth of Four Species of Eucalypt.

1992 ◽  
Vol 40 (5) ◽  
pp. 457 ◽  
Author(s):  
SC Wong ◽  
PE Kriedemann ◽  
GD Farquhar
Keyword(s):  
Leaf Area ◽  
Elevated Co2 ◽  
Eucalyptus Camaldulensis ◽  
Fold Increase ◽  
Wide Distribution ◽  
Growth Responses ◽  
Seedling Vigour ◽  
Co2 Effects ◽  
Whole Plant ◽  
Large Trees

Four eucalypt species were selected to represent two ecologically disparate groups which would be expected to contrast in seedling vigour and in the nature of growth responses to CO2 × nitrogen supply. Eucalyptus camaldulensis and E. cypellocarpa were taken as examples of fast-growing species with a wide distribution, that develop into large trees. By contrast, E. pauciflora and E. pulverulenta become smaller trees, and show a more limited distribution. Seedlings were established in pots (5 L) of a loamy soil and supplied with nutrient solution containing either 1.2 or 6.0 mM NO3- in both ambient (33 Pa) and CO2-enriched (66 Pa) greenhouses. Analysis of growth response to treatments (2 × 2 factorial) was based on destructive harvest of plants sampled on four occasions over 84 days for E. carnaldulensis and E. cypellocarpa, and 100 days for E. pulverulenta and E. pauciflora. A positive CO2 × N interaction on plant dry mass and leaf area was expressed in all species throughout the study period. In E. carnaldulensis and E. cypellocarpa, plant mass was doubled by high N at 33 Pa CO2, compared with a three to four-fold increase at 66 Pa to reach 34g by final harvest. In E. pulverulenta and E. pauciflora, slower growth resulted in about 50% less mass at a given age, but relative increases due to CO2 and N were of a similar order. A distinction can be made between N and CO2 effects on growth processes as follows. When trees were grown on low N, elevated CO2 increased nitrogen-use efficiency (NUE) at both leaf and whole plant levels. On high N, leaf NUE was increased in E. camaldulensis and E. cypellocarpa, but decreased in E. pulverulenta and E. pauciflora. Whole plant NUE showed no consistent response to elevated CO2 when plants were supplied high N. Net assimilation rate (NAR) was increased by elevated CO2 in all species on either N treatment. Moreover, high N increased NAR under either CO2 treatment in all species. There was a positive N × CO2 interaction on NAR in E. carnaldulensis and E. cypellocarpa, but not in E. pulverulenta and E. pauciflora. Growth indices for E. carnaldulensis and E. cypellocarpa species, and especially E. carnaldulensis, generally exceeded those for E. pulverulenta and E. pauciflora in terms of NAR, leaf NUE, N-enhancement of CO2 effects on leaf area and biomass, and non-structural carbohydrate content of foliage.

Influence of radiation and CO2 enrichment on whole plant net CO2 exchange in roses

1991 ◽  
Vol 71 (1) ◽  
pp. 245-252 ◽  
Author(s):  
J. Jiao ◽  
M. J. Tsujita ◽  
B. Grodzinski
Keyword(s):  
Exchange Rate ◽  
Radiant Energy ◽  
Co2 Enrichment ◽  
Co2 Exchange ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Carbon Gain ◽  
Flower Bud ◽  
Whole Plant ◽  
Bud Size

At three stages of flowering shoot development, varying the irradiance and CO2 levels had a similar effect on the whole-plant net CO2 exchange rate (NCER) of Samantha rose plants. At 22 °C, the NCER was saturated at 1000 μmol m−2 s−1 photosynthetically active radiation (PAR). The duration of the light period was also important in determining daily carbon (C) gain. When roses were exposed to a constant daily radiant energy dose of 17.6 μmol m−2 provided either as a 12-h irradiation interval at 410 μmol m−2 s−1 PAR or 24 h of irradiation at 204 μmol m−2 s−1 PAR, the plants exposed to 24 h of continuous irradiation at the lower photon flux density retained 80% more C. Under saturating irradiance, the net photosynthetic rate at an enriched (1000 μL L−1) CO2 level was almost double that at ambient (350 μL L−1) CO2. However, plants grown at ambient and enriched CO2 levels had similar whole-plant NCERs when compared at the same assay CO2 level. Under CO2 enrichment the flower stem was longer and thicker but the flower bud size at harvest was not significantly different to that of roses grown at the ambient CO2 level. Key words: CO2 enrichment, daily carbon gain, net CO2 exchange rate, radiation, Rosa hybrida

Diurnal Time Course of Leaf Gas Exchange Rates and Related Characters in Drought-Acclimated and Irrigated Trifolium Subterraneum.

1995 ◽  
Vol 22 (3) ◽  
pp. 461 ◽  
Author(s):  
J Vadell ◽  
C Cabot ◽  
H Medrano
Keyword(s):  
Gas Exchange ◽  
Exchange Rates ◽  
Water Use Efficiency ◽  
Water Use ◽  
Leaf Gas Exchange ◽  
Trifolium Subterraneum ◽  
Co2 Assimilation ◽  
Carbon Gain ◽  
Assimilation Rate ◽  
Use Efficiency

The effects of drought acclimation on the diurnal time courses of photosynthesis and related characters were studied in Trifolium subterraneum L. leaves during two consecutive late spring days. Leaf CO2 assimilation rate and transpiration rate followed irradiance variations in irrigated plants. Under drought, a bimodal pattern of leaf CO2 assimilation rate developed although stomatal conductance remained uniform and low. Instantaneous water-use efficiency was much higher in droughted plants during the early morning and late evening, while during the middle of the day it was close to the value of irrigated plants. Net carbon gain in plants under drought reached 40% of the carbon gain in irrigated plants with a significant saving of water (80%). Average data derived from midday values of leaf CO2 assimilation rates and instantaneous water-use efficiency did not provide good estimates of the daily carbon gain and water-use efficiency for droughted leaves. Coupled with the morphological changes as a result of acclimation to progressive drought, modifications of diurnal patterns of leaf gas exchange rates effectively contribute to a sustained carbon gain during drought. These modifications significantly improve water-use efficiency, mainly by enabling the plant to take advantage of morning and evening hours with high air humidity.

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