scholarly journals Variation in Leaf Respiration Rates at Night Correlates with Carbohydrate and Amino Acid Supply

2017 ◽  
Vol 174 (4) ◽  
pp. 2261-2273 ◽  
Author(s):  
Brendan M. O’Leary ◽  
Chun Pong Lee ◽  
Owen K. Atkin ◽  
Riyan Cheng ◽  
Tim B. Brown ◽  
...  
Keyword(s):  
Amino Acid ◽  
Leaf Respiration ◽  
Respiration Rates

No difference in leaf respiration rates among temperate, subarctic, and arctic species grown under controlled conditions

1996 ◽  
Vol 74 (2) ◽  
pp. 317-320 ◽  
Author(s):  
Donald E. Collier
Keyword(s):  
Growth Temperature ◽  
Alternative Pathway ◽  
Geographic Origin ◽  
Temperature Acclimation ◽  
Temperate Species ◽  
Leaf Respiration ◽  
Arctic Species ◽  
Respiration Rates ◽  
Controlled Conditions ◽  
Plant Groups

To test the theory that leaf respiration rates are inherently higher in arctic species compared with temperate species, a total of 35 species from temperate, subarctic, and arctic locations were grown under controlled conditions and leaf respiration rates were measured. Regardless of growth temperature (either 10 or 20 °C), leaf respiration rates measured at the growth temperature were independent of a species' geographic origin. In addition, salicylhydroxamic acid inhibited the alternative oxidase equally in all groups of species. Acclimation of leaf respiration to temperature was observed in all three geographic plant groups, i.e., leaf respiration rates of 20 °C-grown plants were not significantly different than rates of 10 °C-grown plants when respiration was measured at the growth temperature. These results suggest that arctic species do not have inherently high leaf respiration rates, higher alternative pathway respiration, or greater temperature acclimation ability compared with temperate species. Keywords: alternative pathway respiration, arctic, leaf respiration, subarctic, temperate, temperature.

Response of Soybeans (Glycine max) and Four Broadleaf Weeds to Reduced Irradiance

Weed Science ◽  
1989 ◽  
Vol 37 (4) ◽  
pp. 570-574 ◽  
Author(s):  
Edward W. Stoller ◽  
Randy A. Myers
Keyword(s):  
Glycine Max ◽  
Leaf Area ◽  
Leaf Respiration ◽  
Common Lambsquarters ◽  
Eastern Black Nightshade ◽  
Black Nightshade ◽  
Respiration Rates ◽  
Growth Irradiance ◽  
Soybean Plants ◽  
Root:Shoot Ratios

Experiments were conducted to determine adaptation characteristics to reduced irradiance of velvetleaf, common lambsquarters, eastern black nightshade, tumble pigweed, and soybean. Plants were grown to the 5- to 8-leaf stage in the greenhouse at ambient radiation (850 μE·m–2·s–1), and 26 and 13% of ambient radiation. Tumble pigweed, a C4plant, had the highest light-saturated photosynthetic rates at all growth irradiances, while common lambsquarters had the highest rates of the four C3species. All species adjusted to reduced irradiance by decreasing light-saturated photosynthesis, leaf respiration rates, root:shoot ratios, and leaf densities, while increasing leaf area ratios (LAR)3. As growth irradiance was reduced, support tissues (roots, stems, and petioles):leaf ratios did not change for common lambsquarters or velvetleaf, increased for soybean, and decreased for eastern black nightshade and tumble pigweed, indicating superior adaptation of the latter two species for efficient light harvesting at reduced growth irradiances. Of these five species, eastern black nightshade had the lowest respiration rate, the highest LAR, and the lowest support:leaf ratio for optimum adaptation to shaded environments.

scholarly journals INFLORESCENCE SINK DEMAND AND LEAF BLACKENING IN PROTEA NERIIFOLIA.

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 617a-617
Author(s):  
Robyn McConchie ◽  
N.Suzanne Lang
Keyword(s):  
Lipid Peroxidation ◽  
Stomatal Conductance ◽  
Exchange Rates ◽  
Pulse Treatment ◽  
Nonstructural Carbohydrates ◽  
Leaf Respiration ◽  
Respiration Rates ◽  
Carbohydrate Depletion ◽  
Sink Demand ◽  
Over Time

A major postharvest problem of Protea neriifolia is premature leaf blackening. Carbohydrate stress, due to floral sink demand, may lead to cellular disorganization and leaf blackening. Leaf blackening, nonstructural carbohydrates, ethylene, carbon exchange rates, stomatal conductance and lipid peroxidation were measured on leaves of vegetative and floral stems preharvest, and during a 7 day dark postharvest period. Postharvest treatments were: 0 or 0.5% sucrose in the vase solution, 20% sucrose pulse, or floral decapitation. Leaf blackening was significantly reduced in vegetative stems and floral stems in the 20% pulse treatment, in comparison to all other treatments. Ethylene production and lipid peroxidation were not associated with leaf blackening in any treatment and leaf respiration rates declined for all treatments over time. The magnitude and rate of leaf blackening was inversely related to leaf starch concentrations, with greatest carbohydrate depletion occurring within 24 h of harvest (by 75-85%). Leaf starch from the 20% pulse treatment increased by 300%, in contrast to declining starch concentrations in all other treatments. The data suggest that the flowerhead functions as the major sink for carbohydrate depletion leading to subsequent leaf blackening.

scholarly journals High Leaf Respiration Rates May Limit the Success of White Spruce Saplings Growing in the Kampfzone at the Arctic Treeline

2021 ◽  
Vol 12 ◽  
Author(s):  
Kevin L. Griffin ◽  
Stephanie C. Schmiege ◽  
Sarah G. Bruner ◽  
Natalie T. Boelman ◽  
Lee A. Vierling ◽  
...  
Keyword(s):  
Picea Glauca ◽  
Temperature Response ◽  
White Spruce ◽  
The Arctic ◽  
Leaf Respiration ◽  
Respiration Rates ◽  
Canopy Position ◽  
Arctic Treeline ◽  
Biological Environment ◽  
The Relationship

Arctic Treeline is the transition from the boreal forest to the treeless tundra and may be determined by growing season temperatures. The physiological mechanisms involved in determining the relationship between the physical and biological environment and the location of treeline are not fully understood. In Northern Alaska, we studied the relationship between temperature and leaf respiration in 36 white spruce (Picea glauca) trees, sampling both the upper and lower canopy, to test two research hypotheses. The first hypothesis is that upper canopy leaves, which are more directly coupled to the atmosphere, will experience more challenging environmental conditions and thus have higher respiration rates to facilitate metabolic function. The second hypothesis is that saplings [stems that are 5–10cm DBH (diameter at breast height)] will have higher respiration rates than trees (stems ≥10cm DBH) since saplings represent the transition from seedlings growing in the more favorable aerodynamic boundary layer, to trees which are fully coupled to the atmosphere but of sufficient size to persist. Respiration did not change with canopy position, however respiration at 25°C was 42% higher in saplings compared to trees (3.43±0.19 vs. 2.41±0.14μmolm−2 s−1). Furthermore, there were significant differences in the temperature response of respiration, and seedlings reached their maximum respiration rates at 59°C, more than two degrees higher than trees. Our results demonstrate that the respiratory characteristics of white spruce saplings at treeline impose a significant carbon cost that may contribute to their lack of perseverance beyond treeline. In the absence of thermal acclimation, the rate of leaf respiration could increase by 57% by the end of the century, posing further challenges to the ecology of this massive ecotone.

scholarly journals High Leaf Respiration Rates May Limit the Success of White Spruce Saplings growing in The Kampfzone at the Arctic Treeline

2021 ◽  
Author(s):  
Kevin L Griffin ◽  
Stephanie C Schmeige ◽  
Sarah G Bruner ◽  
Natalie T Boelman ◽  
Lee A Vierling ◽  
...  
Keyword(s):  
Picea Glauca ◽  
Alternative Hypothesis ◽  
Temperature Response ◽  
White Spruce ◽  
The Arctic ◽  
Leaf Respiration ◽  
Respiration Rates ◽  
Canopy Position ◽  
Arctic Treeline ◽  
The Relationship

Arctic Treeline is the transition from the boreal forest to the treeless tundra and may be determined by growing season temperatures. The physiological mechanisms involved in determining the relationship between the physical and biological environment and the location of treeline are not fully understood. In Northern Alaska we studied the relationship between temperature and leaf respiration in 36 white spruce (Picea glauca) trees, sampling both the upper and lower canopy, to test two research hypotheses (H0). The first H01 is that canopy position will not influence leaf respiration. The associated alternative hypothesis (HA) is that the upper canopy leaves which are more directly coupled to the atmosphere will experience more challenging environmental conditions and thus have higher respiration rates to facilitate metabolic function. The second H02 is that tree size will not influence leaf respiration. The associated HA is that saplings (stems that are 5-10 cm DBH (diameter at breast height)) will have higher respiration rates than trees (stems ≥ 10 cm DBH) since saplings represent the transition from seedlings growing in the more favorable aerodynamic boundary layer, to trees which are fully coupled to the atmosphere but of sufficient size to persist. Respiration did not change with canopy position, however respiration at 25°C was 42% higher in saplings compared to trees (3.43 ± 0.19 vs. 2.41 ± 0.14 μmol m-2s-1). Furthermore, there were significant differences in the temperature response of respiration, and seedlings reached their maximum respiration rates at 59°C, more than two degrees higher than trees. Our results demonstrate that the respiratory characteristics of white spruce saplings at treeline are extreme, imposing a significant carbon cost that may contribute to their lack of perseverance beyond treeline. In the absence of thermal acclimation, the rate of leaf respiration could increase by 57% by the end of the century, posing further challenges to the ecology of this massive ecotone.

GENOTYPIC DIFFERENCES IN DARK RESPIRATION OF MATURE LEAVES IN WINTER WHEAT (Triticum aestivum L.)

1988 ◽  
Vol 68 (3) ◽  
pp. 669-675 ◽  
Author(s):  
M. WINZELER ◽  
D. E. McCULLOUGH ◽  
L. A. HUNT
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Leaf Size ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Mature Leaf ◽  
Genotypic Differences ◽  
Leaf Respiration ◽  
Mature Leaves ◽  
Respiration Rates

Oxygen uptake of mature leaves was measured on a range of winter wheat (Triticum aestivum L.) genotypes both indoors (four genotypes) and in the field (six genotypes). The relationship among mature leaf respiration, leaf size, specific leaf weight and leaf nutrient status was investigated. Correlations between leaf respiration and total plant dry weight as well as tiller number were calculated in the indoor study. Significant differences of 6–25% in mature leaf respiration rates were evident among winter wheat genotypes in the indoor as well as in the field study. Leaf position as well as environment had a marked influence on the order and magnitude of genotype effects on mature leaf respiration rates. Leaf respiration was not related to specific leaf weight, leaf nitrogen, or phosphorus content, but was negatively related to leaf size. Leaf respiration was not related to total dry weight and tiller number of single plants grown indoors.Key words: Respiration, genotypic differences, wheat (winter), Triticum aestivum L.

The staining pattern of the tropomyosin sequence is displayed in a new paracrystal

1986 ◽  
Vol 44 ◽  
pp. 150-151
Author(s):  
M.K. Lamvik ◽  
L.L. Klatt
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Staining Pattern ◽  
Banding Patterns ◽  
Mass Thickness ◽  
New Form

Tropomyosin paracrystals have been used extensively as test specimens and magnification standards due to their clear periodic banding patterns. The paracrystal type discovered by Ohtsuki1 has been of particular interest as a test of unstained specimens because of alternating bands that differ by 50% in mass thickness. While producing specimens of this type, we came across a new paracrystal form. Since this new form displays aligned tropomyosin molecules without the overlaps that are characteristic of the Ohtsuki-type paracrystal, it presents a staining pattern that corresponds to the amino acid sequence of the molecule.

Electron probe x-ray microanalysis and electron microscopy of amino acid absorption and transport by the small intestine: inhibition by chemical poisons and correlation to the elemental composition of the epithelial cells

1986 ◽  
Vol 44 ◽  
pp. 134-135
Author(s):  
A. J. Tousimis
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Elemental Composition ◽  
Isotope Labeling ◽  
Structural Components ◽  
X Ray ◽  
Human Small Intestine ◽  
Transport Studies

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.

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