scholarly journals Photosynthesis and Rubisco kinetics in spring wheat and meadow fescue under conditions of simulated climate change with elevated CO2 and increased temperatures

1999 ◽  
Vol 8 (4-5) ◽  
pp. 441-457 ◽  
Author(s):  
K. HAKALA ◽  
R. HELIÖ ◽  
E.-M. TUHKANEN
Keyword(s):  
Carbon Dioxide ◽  
Elevated Co2 ◽  
Spring Wheat ◽  
Elevated Temperatures ◽  
Carbon Dioxide Concentration ◽  
Meadow Fescue ◽  
Bisphosphate Carboxylase ◽  
Ambient Temperatures ◽  
Rate Of Photosynthesis ◽  
Sink Size

Spring wheat (Triticum aestivum L.cv.Polkka)and meadow fescue (Festuca pratensis Hudson cv. Kalevi)cwere grown in ambient and elevated (700 µl l -1 )carbon dioxide concentration both at present ambient temperatures and at temperatures 3°C higher than at present simulating a future climate.The CO2 concentrations were elevated in large (3 m in diameter)open top chambers and the temperatures in a greenhouse built over the experimental field.The photosynthetic rate of both wheat and meadow fescue was 31 –37%higher in elevated carbon dioxide (eCO2 )than in ambient CO 2 (aCO2 )throughout the growing season.The enhancement in wheat photosynthesis in eCO2 declined 10 –13 days before yellow ripeness,at which point the rate of photosynthesis in both CO 2 treatments declined.The stomatal conductance of wheat and meadow fescue was 23–36% lower in eCO2 than in aCO2 .The amount and activity of ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) in wheat were lower under conditions of eCO2 ,except at elevated temperatures in 1993 when there was a clear yield increase.There was no clear change in the amount and activity of Rubisco in meadow fescue under eCO2 at either elevated or ambient temperature.This suggests that adaptation to elevated CO2 at biochemical level occurs only when there is insufficient sink for photosynthetic products.While the sink size of wheat can be increased only by introducing new,more productive genotypes,the sink size of meadow fescue can be regulated by fitting the cutting schedule to growth.;

scholarly journals The effects of prolonged exposure to elevated temperatures and elevated CO2 levels on the growth, yield and dry matter partitioning of field-sown meadow fescue

1996 ◽  
Vol 5 (3) ◽  
pp. 285-298 ◽  
Author(s):  
Kaija Hakala ◽  
Timo Mela
Keyword(s):  
Elevated Co2 ◽  
Root Biomass ◽  
Elevated Temperatures ◽  
Prolonged Exposure ◽  
Total Yield ◽  
Growing Season ◽  
Soluble Carbohydrate ◽  
Meadow Fescue ◽  
Dry Matter Partitioning ◽  
Ambient Temperatures

Field-sown meadow fescue (Festuca pratensis, cv. Kalevi) stands were exposed to elevated temperatures (+3°C) and elevated CO2, (700 ppm) levels in two experiments conducted in 1992-1993 (experiment 1) and in 1994-1995 (experiment 2). Total aboveground yield was, on average, 38% higher at elevated than at ambient temperatures. At ambient temperatures elevated CO2 increased the number of tillers by 63% in 1992, 24% in 1993, 90% in 1994 and 14% in 1995. At elevated temperatures, the increase in tiller number in elevated CO2 was seen only in the first growing seasons after sowing. The total yield in a growing season was about 10% higher in elevated CO2 in experiment 1. In experiment 2 the yield was more than 20% higher in elevated CO2 at elevated temperatures, whereas at ambient temperatures the rise in CO2 level had no effect on the yield; the root biomass, however, increased by more than 30%. In elevated CO2 at ambient temperatures the root biomass also increased in experiment I, but at elevated temperatures there was no consistent change. The soluble carbohydrate content of above-ground biomass was 5-48% higher in elevated CO2 at most of the measuring times during the growing season, but the nitrogen content did not show a clear decrease. The reasons for the lack of a marked increase in biomass in elevated CO2 despite a 40-60% increase in photosynthesis are discussed.

Photosynthesis and crop: problems, achievements, research prospects

2020 ◽  
pp. 251-256
Author(s):  
V.I. Dubrovsky ◽  
◽  
V.V. Schwartau ◽  
L.M. Mykhalska ◽  
◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Elevated Temperatures ◽  
Photosynthetic Apparatus ◽  
Carbon Dioxide Concentration ◽  
Woody Species ◽  
Average Yield ◽  
Sugar Beets ◽  
Photosynthetic Productivity ◽  
New Directions

The problems of the agricultural the crops productivity increasing have been considered including woody ones, and of improving the photosynthetic apparatus characteristics. On the basis of literature data and results of own experiments regularities of formation of agrocenoses with the increased photosynthetic productivity are analyzed. The key photosyn-thetic apparatus characteristics are considered that determine the photosynthesis productivity and efficiency. The changes in the intensity of photosynthesis of plants caused by the changes in the atmospheric carbon dioxide concentra-tion and temperature, are shown as well as the dependence of the photosynthesis intensity on its concentration. The re-view of the explorations results as regards increasing the agricultural crops photosynthetic apparatus productivity shows that the increase of the carbon dioxide amount in the atmosphere to 1.5 % brings about the directly proportional rise of the photosynthesis intensity. An example is given of growing sugar beets, which form an average yield per hectare of its crops, absorbing about 300-400 kg of carbon dioxide per day. The nature of the daytime photosynthesis in the woody species has common sings, although there is a photosynthesis depression in these plants at noon, due to the in-creased respiration during this period at elevated temperatures or the maximum radiation, which is stressful for the plant. The conclusion has been made that one of the ways to increase the photosynthesis productivity is to increase the carbon dioxide concentration in the air. The further efforts of breeders in the creation of new cultivars should be aimed at in-creasing the plant photosynthetic apparatus activity. These are just new directions in science.

Sustained growth and increased tolerance to glyphosate observed in a C3 perennial weed, quackgrass (Elytrigia repens), grown at elevated carbon dioxide

2000 ◽  
Vol 27 (2) ◽  
pp. 159 ◽  
Author(s):  
Lewis H. Ziska ◽  
John R. Teasdale
Keyword(s):  
Carbon Dioxide ◽  
Elevated Co2 ◽  
Atmospheric Carbon Dioxide ◽  
Plant Biomass ◽  
Carbon Dioxide Concentration ◽  
Young Cohort ◽  
Glyphosate Tolerance ◽  
Perennial Weed ◽  
Elytrigia Repens ◽  
Co2 Treatment

Although the response of crop plants to rising atmospheric carbon dioxide concentration ([CO2]) has been well characterized, little is known concerning the long-term growth and/or photosynthetic response of peren-nial weeds. The growth and photosynthetic characteristics of three cohorts of a perennial C3 weedy species, quack-grass (Elytrigia repens (L.) Nevski) were examined at ~380 µmol mol−1 (ambient) and 720 µmol mol−1 (elevated) [CO2] in temperature-controlled greenhouses during 1998 and early 1999. Different cohorts were used to assess the sensitivity of growth, photosynthesis and glyphosate tolerance to elevated [CO2] for different stages in the life cycle of quackgrass. For the ‘old’ cohort, planted on Day of Year (DOY) 187, elevated [CO2] resulted in a consistent stim-ulation of single leaf photosynthesis, vegetative and whole plant biomass relative to the ambient [CO2] condition over a 231-d period. Data from the ‘intermediate’ (DOY 268) and ‘young’ cohorts (DOY 350) indicated that the stimula-tion of biomass at the elevated [CO2] was time-dependent. To determine if the observed stimulation of growth at ele-vated [CO2] altered tolerance to chemical weed control, glyphosate [(N-phosphonomethyl)glycine] was applied to each cohort and each [CO2] treatment at rates of 0 (control) and 2.24 kg ai ha−1 (sprayed). Tolerance was determined by following the growth and slope of each cohort at the growth [CO2] treatment for a 28-d period following glyphosate application. For the young cohort, [CO2] had no affect on glyphosate tolerance; however, an application rate of 2.24 kg ai ha−1, reduced but did not eliminate growth for the intermediate and old cohorts grown at elevated [CO2]. The basis for increased glyphosate tolerance at elevated [CO2] for these cohorts was unclear, but was not related to plant size at the time of glyphosate application. Data from this experiment indicate that sustained stimula-tion of photosynthesis and growth in perennial weeds could occur as atmospheric [CO2] increases, with a reduction in chemical control effectiveness and potential increases in weed/crop competition.

scholarly journals Arrangement of experiments for simulating the effects of elevated temperatures and elevated CO2 levels on field-sown crops in Finland

1996 ◽  
Vol 5 (1) ◽  
pp. 25-47 ◽  
Author(s):  
Kaija Hakala ◽  
Timo Mela ◽  
Heikki Laurila ◽  
Timo Kaukoranta
Keyword(s):  
Open Field ◽  
Elevated Co2 ◽  
Elevated Temperatures ◽  
Spring Barley ◽  
Meadow Fescue ◽  
Black Currant ◽  
Experimental Conditions ◽  
Co2 Concentrations ◽  
Term Variation ◽  
Co2 Level

The experimental plants: spring wheat, winterwheat, spring barley, meadow fescue, potato, strawberry and black currant were sown or planted directly in the field, part of which was covered by an automatically controlled greenhouse to elevate the temperature by 3°C. The temperature of the other part of the field (open field) was not elevated, but the field was covered with the same plastic film as the greenhouse to achieve radiation and rainfall conditions comparable to those in the greenhouse. To elevate the CO2 concentrations, four open top chambers (OTC) were built for the greenhouse, and four for the open field. Two of these, both in the greenhouse and in the open field, were supplied with pure CO2 to elevate their CO2 level to 700 ppm. The temperatures inside the greenhouse followed accurately the desired level. The relative humidity was somewhat higher in the greenhouse and in the OTC:s than in the open field, especially after the modifications in the ventilation of the greenhouse and in the OTC:s in 1994. Because the OTC:s were large (3 m in diameter), the temperatures inside them differed very little from the surrounding air temperature. The short-term variation in the CO2 concentrations in the OTC:s with elevated CO2 was, however, quite high. The control of the CO2 concentrations improved each year from 1992 to 1994, as the CO2 supplying system was modified. The effects of the experimental conditions on plant growth and phenology are discussed.

scholarly journals Estimating the Excess Investment in Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase in Leaves of Spring Wheat Grown under Elevated CO2

1998 ◽  
Vol 118 (3) ◽  
pp. 945-955 ◽  
Author(s):  
Julian C. Theobald ◽  
Rowan A.C. Mitchell ◽  
Martin A.J. Parry ◽  
David W. Lawlor
Keyword(s):  
Elevated Co2 ◽  
Spring Wheat ◽  
Bisphosphate Carboxylase

EFFECT OF LEAF MATURITY, TEMPERATURE, CARBON DIOXIDE CONCENTRATION, AND LIGHT INTENSITY ON RATE OF PHOTOSYNTHESIS IN CLONAL LINES OF THE LOWBUSH BLUEBERRY, VACCINIUM ANGUSTIFOLIUM AIT. UNDER LABORATORY CONDITIONS

1965 ◽  
Vol 43 (8) ◽  
pp. 893-900 ◽  
Author(s):  
F. R. Forsyth ◽  
I. V. Hall
Keyword(s):  
Carbon Dioxide ◽  
Light Intensity ◽  
Constant Temperature ◽  
Carbon Dioxide Concentration ◽  
Vaccinium Angustifolium ◽  
Leaf Maturity ◽  
Agronomic Characteristics ◽  
Lowbush Blueberry ◽  
Rate Of Photosynthesis ◽  
Clonal Lines

The rate of apparent photosynthesis of the lowbush blueberry was determined in Warburg flasks using Pardee's CO2 buffers. A marked increase in rate of O2 evolution occurred as the temperature was raised from 13.0 to 29.5 °C. With a constant temperature of 25.0 °C the rate of O2 evolution increased as the CO2 concentration increased from 0.2 to 0.8%. The young and middle-aged leaves had a higher rate of apparent photosynthesis than the older leaves. The rate was higher at a light intensity of 1000 ft-c than at 650 ft-c at a CO2 concentration of 0.4%. At the higher light intensity a lowbush blueberry clone selected on the basis of superior agronomic characteristics had a significantly higher rate of apparent pholosynthesis than an average clone.

Enhancing the chelation capacity of rice to maximise iron and zinc concentrations under elevated atmospheric carbon dioxide

2013 ◽  
Vol 40 (2) ◽  
pp. 101 ◽  
Author(s):  
Alexander A. T. Johnson
Keyword(s):  
Carbon Dioxide ◽  
Elevated Co2 ◽  
Atmospheric Carbon Dioxide ◽  
Carbon Dioxide Concentration ◽  
Nutritional Composition ◽  
Rice Grain ◽  
Cereal Grain ◽  
Iron And Zinc ◽  
Zinc Concentrations ◽  
Atmospheric Carbon

Roughly half of the Earth’s seven billion people rely on rice as their primary source of food. The milled grain of rice, often referred to as polished or white rice, serves as a rich source of energy but is low in protein and several essential micronutrients such as iron and zinc. As a result, billions of people in rice-based countries suffer the debilitating effects of protein-energy and micronutrient malnutrition with symptoms including iron-deficiency anaemia, growth retardation and blindness. By 2050, the Earth’s atmospheric carbon dioxide concentration ([CO2]) is expected to reach 550 μmol mol–1, representing a 70% increase from today’s concentration of 392 μmol mol–1. The impacts of elevated [CO2] on plant growth will likely include agronomically useful traits such as increased biomass, yield and water-use efficiency. However, increased plant productivity is likely to be accompanied by decreased protein and micronutrient mineral concentrations of cereal grain. This review focuses on the effects of carbon dioxide-enrichment on rice physiology and nutritional composition and proposes increased activity of the Strategy II iron uptake pathway as a promising method to maintain or increase iron and zinc concentrations in rice grain, and perhaps cereal grain in general, under elevated [CO2].

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