Summer Dormancy in an Endangered Riparian Shrub Myricaria laxiflora: Changes in Branches, Leaves, and Nonstructural Carbohydrates

Black spruce seedlings (Piceamariana Mill.) were exposed to either elevated (1000 ppm) or ambient (340 ppm) atmospheric CO2 levels at different stages of seedling development over a winter greenhouse production cycle. Seedlings germinated in early February and were placed in CO2 chambers for either 3 or 6 weeks during March, April, May, or August. Total seedling biomass increased under high CO2 conditions for the March, April, and May stages of development, but showed no significant response in August. The greater part of the CO2 response occurred during the second 3 weeks of exposure in March and April but during the first 3 weeks of exposure in May. In September, those seedlings exposed to CO2 in April and May had 30 and 14%, respectively, greater biomass than control seedlings, but seedlings from the other stages of development no longer had significant differences remaining from the CO2 treatment. This suggests that it could be very efficient to give a short well-timed CO2 pulse at the beginning of the production cycle in hopes of producing a size difference that is maintained throughout the remainder of the greenhouse production cycle under ambient levels of CO2. Short-term exposure to elevated CO2 also increased the ratio of shoot dry weight to total height for the March, April, and May stages of development. The ratio of total nonstructural carbohydrates to free amino acids was negatively correlated (r2 = 0.98) with the allocation of new growth between shoots and roots as measured by the allocation coefficient, k (milligrams shoot growth per milligrams root growth). As seedlings developed along their seasonal growth cycle, ratios of total nonstructural carbohydrates to free amino acids increased and the values for k decreased. The effect of CO2 enrichment on these two factors is discussed. Monitoring total nonstructural carbohydrate and free amino acid concentrations in foliage could have potential as a method to predict the percentage of carbon allocated to root systems of entire forest stands as well as of individual tree seedlings.

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Changes in levels of foliar carbohydrates and myo-inositol before premature leaf senescence of Populus nigra induced by a mixture of O3 and SO2

Canadian Journal of Botany ◽

10.1139/b96-120 ◽

1996 ◽

Vol 74 (6) ◽

pp. 965-970 ◽

Cited By ~ 11

Author(s):

R. C. Fialho ◽

J. Bücker

Keyword(s):

Air Pollution ◽

Leaf Senescence ◽

Populus Nigra ◽

Continuous Exposure ◽

Nonstructural Carbohydrates ◽

Progressive Decline ◽

Total Nonstructural Carbohydrates ◽

Leaf Yellowing ◽

Premature Leaf Senescence ◽

Early Indication

Specimens of Populus nigra L. cv. Loenen exhibit premature leaf senescence when exposed for a few weeks to realistic air pollution. In this study, the changes in levels of foliar carbohydrates and myo-inositol (MI) due to 30 ± 1 nL/L O3 + 12 ± 1 nL/L SO2 from the onset of exposure to the occurrence of premature abscission is presented. Petioles and laminae of the 12 oldest leaves were separately analysed on days 0, 4, 8, 12, 16, 20, 22, and 32 of continuous exposure, which was performed in open-top chambers (OTC). On days 8 to 12, clearly prior to yellowing (starting on day 22), total nonstructural carbohydrates (TNC; starch + raffinose + sucrose + glucose + fructose + MI) in the fumigated laminae exceeded that in controls by about 30%. This increase was due to higher amounts of different soluble forms, while starch remained unaltered. From day 20 onwards, the level of TNC in the fumigated laminae progressively fell below that in controls. This decrease was due to a progressive decline in starch, which had started on day 16 and was dominating, although glucose and raffinose increased significantly. In the petioles, starch, sucrose, and glucose decreased because of fumigation with the occurrence of leaf yellowing, while raffinose increased. In contrast, MI in the petioles progressively accumulated directly on exposure until leaf yellowing occurred. The results are discussed in terms of the "general adaption syndrome" of H. Selye (1936. Nature (London), 138: 32). The marked MI response in petioles is concluded to be an early indication of phytorelevant O3 + SO2 pollution. Keywords: air pollution, carbohydrates, myo-inositol, pigments, Populus nigra L., senescence, stress.

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Summer Dormancy Trait as a Strategy to Provide Perennial Cool-Season Grass Forage Alternatives in Southern Latitude Environments Affected by Climate Change

Agronomy Journal ◽

10.2134/agronj14.0628 ◽

2015 ◽

Vol 107 (4) ◽

pp. 1227-1234 ◽

Cited By ~ 1

Author(s):

Dariusz P. Malinowski ◽

William E. Pinchak

Keyword(s):

Climate Change ◽

Cool Season ◽

Southern Latitude ◽

Summer Dormancy ◽

Cool Season Grass

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Efficiency of water for extraction of total nonstructural carbohydrates from plant tissue

Journal of the Science of Food and Agriculture ◽

10.1002/jsfa.2740220904 ◽

1971 ◽

Vol 22 (9) ◽

pp. 445-447 ◽

Cited By ~ 13

Author(s):

Dale Smith

Keyword(s):

Plant Tissue ◽

Nonstructural Carbohydrates ◽

Total Nonstructural Carbohydrates

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Effects of dietary nonstructural carbohydrates and protein sources on feeding behavior of tethered heifers fed high-concentrate diets1

Journal of Animal Science ◽

10.2527/2006.8451197x ◽

2006 ◽

Vol 84 (5) ◽

pp. 1197-1204 ◽

Cited By ~ 18

Author(s):

A. Rotger ◽

A. Ferret ◽

X. Manteca ◽

J. L. Ruiz de la Torre ◽

S. Calsamiglia

Keyword(s):

Feeding Behavior ◽

Nonstructural Carbohydrates ◽

Protein Sources

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Persistence and productivity of phalaris (Phalaris aquatica) germplasm in dry marginal rainfall environments of south-eastern Australia

Crop and Pasture Science ◽

10.1071/cp17203 ◽

2017 ◽

Vol 68 (8) ◽

pp. 781

Author(s):

R. A. Culvenor ◽

M. R. Norton ◽

J. De Faveri

Keyword(s):

Environmental Benefits ◽

Annual Rainfall ◽

Summer Drought ◽

Environment Interaction ◽

Phalaris Aquatica ◽

Mixed Farming ◽

Eastern Australia ◽

Summer Dormancy ◽

Average Annual Rainfall ◽

Establishment Phase

Perennial grasses have production and environmental benefits in areas of southern Australia typified by the mixed farming zone of southern New South Wales (NSW). The perennial grass phalaris (Phalaris aquatica L.) is widely used in southern Australia; however, it would find more use in the mixed farming zone if its persistence in marginal rainfall areas (450–500 mm average annual rainfall) were improved. We evaluated a range of germplasm (n = 29) including wild accessions, lines bred from these, and existing cultivars for persistence and production at three sites in a summer-dry area of southern NSW with 430–460-mm average annual rainfall. Two sites were used over 4 years and the third site over 5 years. Summer dormancy, maturity time and seedling growth were also assessed. Analysis of genotype × environment interaction employing factor analytic models and accounting for spatial and temporal correlations indicated that changes in persistence occurred mainly over time rather than between sites. Ranking changes occurred in the dry establishment phase of the experiment and during a severe final summer drought, with few changes occurring in the intervening high-rainfall years. Lines that survived the establishment phase best had vigorous seedlings and earlier maturity, whereas those surviving the final summer best were earlier maturing and higher in summer dormancy with high winter-growth activity. Some later maturing lines within the higher summer dormancy group were less persistent. Some accessions from North Africa were the most persistent; also, populations bred from these and other more persistent accessions generally persisted and produced better than cultivars used presently. However, present cultivars were capable of high yield in the higher rainfall years. We suggest that persistence of higher summer dormancy cultivars over very dry years could be improved by selecting for earlier maturity time.

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CO2 Assimilation, Photosynthetic Enzymes, and Carbohydrates of `Concord' Grape Leaves in Response to Iron Supply

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.129.5.0738 ◽

2004 ◽

Vol 129 (5) ◽

pp. 738-744 ◽

Cited By ~ 11

Author(s):

Li-Song Chen ◽

Brandon R. Smith ◽

Lailiang Cheng

Keyword(s):

Sucrose Concentration ◽

Calvin Cycle ◽

Sucrose Phosphate Synthase ◽

Nonstructural Carbohydrates ◽

Bisphosphate Carboxylase ◽

Chl A ◽

Photosynthetic Enzymes ◽

Fe Content ◽

Significant Difference ◽

Assimilation Capacity

Own-rooted 1-year-old `Concord' grapevines (Vitis labruscana Bailey) were fertigated twice weekly for 11 weeks with 1, 10, 20, 50, or 100 μm iron (Fe) from ferric ethylenediamine di (o-hydroxyphenylacetic) acid (Fe-EDDHA) in a complete nutrient solution. As Fe supply increased, leaf total Fe content did not show a significant change, whereas active Fe (extracted by 2,2′-dipyridyl) content increased curvilinearly. Chlorophyll (Chl) content increased as Fe supply increased, with a greater response at the lower Fe rates. Chl a: b ratio remained relatively constant over the range of Fe supply, except for a slight increase at the lowest Fe treatment. Both CO2 assimilation and stomatal conductance increased curvilinearly with increasing leaf active Fe, whereas intercellular CO2 concentrations decreased linearly. Activities of key enzymes in the Calvin cycle, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), NADP-glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphoribulokinase (PRK), stromal fructose-1,6-bisphosphatase (FBPase), and a key enzyme in sucrose synthesis, cytosolic FBPase, all increased linearly with increasing leaf active Fe. No significant difference was found in the activities of ADP-glucose pyrophosphorylase (AGPase) and sucrose phosphate synthase (SPS) of leaves between the lowest and the highest Fe treatments, whereas slightly lower activities of AGPase and SPS were observed in the other three Fe treatments. Content of 3-phosphoglycerate (PGA) increased curvilinearly with increasing leaf active Fe, whereas glucose-6-phosphate (G6P), fructose-6-phosphate (F6P), and the ratio of G6P: F6P remained unchanged over the range of Fe supply. Concentrations of glucose, fructose, sucrose, starch, and total nonstructural carbohydrates (TNC) at both dusk and predawn increased with increasing leaf active Fe. Concentrations of starch and TNC at any given leaf active Fe content were higher at dusk than at predawn, but both glucose and fructose showed the opposite trend. No difference in sucrose concentration was found at dusk or predawn. The export of carbon from starch breakdown during the night, calculated as the difference between dusk and predawn measurements, increased as leaf active Fe content increased. The ratio of starch to sucrose at both dusk and predawn also increased with increasing leaf active Fe. In conclusion, Fe limitation reduces the activities of Rubisco and other photosynthetic enzymes, and hence CO2 assimilation capacity. Fe-deficient grapevines have lower concentrations of nonstructural carbohydrates in source leaves and, therefore, are source limited.

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