Acclimation Of Respiration Research Articles

Acclimation of photosynthesis and respiration to simulated climatic warming in northern and southern populations of Acer saccharum: laboratory and field evidence.

Physiological acclimation and genotypic adaptation to prevailing temperatures may influence forest responses to future climatic warming. We examined photosynthetic and respiratory responses of sugar maple (Acer saccharum Marsh.) from two portions of the species' range for evidence of both phenomena in a laboratory study with seedlings. A field study was also conducted to assess the impacts of temperature acclimation on saplings subjected to an imposed temperature manipulation (4 degrees C above ambient temperature). The two seedling populations exhibited more evidence of physiological acclimation to warming than of ecotypic adaptation, although respiration was less sensitive to short-term warming in the southern population than in the northern population. In both seedling populations, thermal compensation increased photosynthesis by 14% and decreased respiration by 10% in the warm-acclimated groups. Saplings growing in open-top field chambers at ambient temperature and 4 degrees C above ambient temperature showed evidence of temperature acclimation, but photosynthesis did not increase in response to the 4 degrees C warming. On the contrary, photosynthetic rates measured at the prevailing chamber temperature throughout three growing seasons were similar, or lower (12% lower on average) in saplings maintained at 4 degrees C above ambient temperature compared with saplings maintained at ambient temperature. However, the long-term photosynthetic temperature optimum for saplings in the field experiment was higher than it was for seedlings in either the 27 or the 31 degrees C growth chamber. Respiratory acclimation was also evident in the saplings in the field chambers. Saplings had similar rates of respiration in both temperature treatments, and respiration showed little dependence on prevailing temperature during the growing season. We conclude that photosynthesis and respiration in sugar maple have the potential for physiological acclimation to temperature, but exhibit a low degree of genetic adaptation. Some of the potential for acclimation to a 4 degrees C increase above a background of naturally fluctuating temperatures may be offset by differences in water relations, and, in the long term, may be obscured by the inherent variability in rates under field conditions. Nevertheless, physiologically based models should incorporate seasonal acclimation to temperature and permit ecotypic differences to influence model outcomes for those species with high genetic differentiation between regions.

Acclimation of snow gum (Eucalyptus pauciflora) leaf respiration to seasonal and diurnal variations in temperature: the importance of changes in the capacity and temperature sensitivity of respiration

ABSTRACTWe investigated the relationship between daily and seasonal temperature variation and dark respiratory CO2 release by leaves of snow gum (Eucalyptus pauciflora Sieb. ex Spreng) that were grown in their natural habitat or under controlled‐environment conditions. The open grassland field site in SE Australia was characterized by large seasonal and diurnal changes in air temperature. On each measurement day, leaf respiration rates in darkness were measured in situ at 2–3 h intervals over a 24 h period, with measurements being conducted at the ambient leaf temperature. The rate of respiration at a set measuring temperature (i.e. apparent ‘respiratory capacity’) was greater in seedlings grown under low average daily temperatures (i.e. acclimation occurred), both in the field and under controlled‐environment conditions. The sensitivity of leaf respiration to diurnal changes in temperature (i.e. the Q10 of leaf respiration) exhibited little seasonal variation over much of the year. However, Q10 values were significantly greater on cold winter days (i.e. when daily average and minimum air temperatures were below 6° and –1 °C, respectively). These differences in Q10 values were not due to bias arizing from the contrasting daily temperature amplitudes in winter and summer, as the Q10 of leaf respiration was constant over a wide temperature range in short‐term experiments. Due to the higher Q10 values in winter, there was less difference between winter and summer leaf respiration rates measured at 5 °C than at 25 °C. The net result of these changes was that there was relatively little difference in total daily leaf respiratory CO2 release per unit leaf dry mass in winter and summer. Under controlled‐environment conditions, acclimation of respiration to growth temperature occurred in as little as 1–3 d. Acclimation was associated with a change in the concentration of soluble sugars under controlled conditions, but not in the field. Our data suggest that acclimation in the field may be associated with the onset of cold‐induced photo‐inhibition. We conclude that cold‐acclimation of dark respiration in snow gum leaves is characterized by changes in both the temperature sensitivity and apparent ‘capacity’ of the respiratory apparatus, and that such changes will have an important impact on the carbon economy of snow gum plants.

Acclimation of respiration to temperature and CO2 in seedlings of boreal tree species in relation to plant size and relative growth rate

SummaryThe role of acclimation of dark respiration to temperature and CO2 concentration and its relationship to growth are critical in determining plant response to predicted global change. We explored temperature acclimation of respiration in seedlings of tree species of the North American boreal forest. Populus tremuloides, Betula papyrifera, Larix laricina, Pinus banksiana, and Picea mariana plants were grown from seed in controlled‐environments at current and elevated concentrations of CO2 (370 and 580 μmol mol–1) in combination with three temperature treatments of 18/12, 24/18, and 30/24 °C (light/dark period). Specific respiration rates of roots and shoots acclimated to temperature, damping increases in rates across growth‐temperature environments compared to short‐term temperature responses. Compared at a standard temperature, root and shoot respiration rates were, on average, 40% lower in plants grown at the highest compared to lowest growth temperature. Broad‐leaved species had a lower degree of temperature acclimation of respiration than did the conifers. Among species and treatment combinations, rates of respiration were linearly related to size and relative growth rate, and relationships were comparable among growth environments. Specific respiration rates and whole‐plant respiratory CO2 efflux as a proportion of daily net CO2 uptake increased at higher growth temperatures, but were minimally affected by CO2 concentration. Whole‐plant specific respiration rates were two to three times higher in broad‐leaved than coniferous species. However, compared to faster‐growing broad‐leaved species, slower‐growing conifers lost a larger proportion of net daily CO2 uptake as respiratory CO2 efflux, especially in roots. Interspecific variation in acclimation responses of dark respiration to temperature is more important than acclimation of respiration to CO2 enrichment in modifying tree seedling growth responses to projected increases in CO2 concentration and temperature.

Changes in leaf nitrogen and carbohydrates underlie temperature and CO2 acclimation of dark respiration in five boreal tree species

We tested the hypothesis that acclimation of foliar dark respiration to CO2 concentration and temperature is associated with adjustments in leaf structure and chemistry. Populus tremuloides Michx., Betula papyrifera Marsh., Larix laricina (Du Roi) K. Koch, Pinus banksiana Lamb., and Picea mariana (Mill.) B.S.P. were grown from seed in combined CO2 (370 or 580 μmol mol–1) and temperature treatments (18/12, 24/18, or 30/24 °C). Temperature and CO2 effects were predominately independent. Specific respiration rates partially acclimated to warmer thermal environments through downward adjustment in the intercept, but not Q10 of the temperature–response functions. Temperature acclimation of respiration was larger for conifers than broad‐leaved species and was associated with pronounced reductions in leaf nitrogen concentrations in conifers at higher growth temperatures. Short‐term increases in CO2 concentration did not inhibit respiration. Growth in the elevated CO2 concentration reduced leaf nitrogen and increased non‐structural carbohydrate concentrations. However, for a given nitrogen concentration, respiration was higher in leaves grown in the elevated CO2 concentration, as rates increased with increasing carbohydrates. Across species and treatments, respiration rates were a function of both leaf nitrogen and carbohydrate concentrations (R2 = 0·71, P < 0·0001). Long‐term acclimation of foliar dark respiration to temperature and CO2 concentration is largely associated with changes in nitrogen and carbohydrate concentrations.

Stem respiration of ponderosa pines grown in contrasting climates: implications for global climate change.

We examined the effects of climate and allocation patterns on stem respiration in ponderosa pine (Pinus ponderosa) growing on identical substrate in the cool, moist Sierra Nevada mountains and the warm, dry, Great Basin Desert. These environments are representative of current climatic conditions and those predicted to accompany a doubling of atmospheric CO2, respectively, throughout the range of many western north American conifers. A previous study found that trees growing in the desert allocate proportionally more biomass to sapwood and less to leaf area than montane trees. We tested the hypothesis that respiration rates of sapwood are lower in desert trees than in montane trees due to reduced stem maintenance respiration (physiological acclimation) or reduced construction cost of stem tissue (structural acclimation). Maintenance respiration per unit sapwood volume at 15°C did not differ between populations (desert: 6.39 ± 1.14 SE μmol m-3 s-1, montane: 6.54 ± 1.13 SE μmol m-3 s-1, P = 0.71) and declined with increasing stem diameter (P = 0.001). The temperature coefficient of respiration (Q 10) varied seasonally within both environments (P = 0.05). Construction cost of stem sapwood was the same in both environments (desert: 1.46 ± 0.009 SE g glucose g-1 sapwood, montane: 1.48 ± 0.009 SE glucose g-1 sapwood, P = 0.14). Annual construction respiration calculated from construction cost, percent carbon and relative growth rate was greater in montane populations due to higher growth rates. These data provide no evidence of respiratory acclimation by desert trees. Estimated yearly stem maintenance respiration was greater in large desert trees than in large montane trees because of higher temperatures in the desert and because of increased allocation of biomass to sapwood. By analogy, these data suggest that under predicted increases in temperature and aridity, potential increases in aboveground carbon gain due to enhanced photosynthetic rates may be partially offset by increases in maintenance respiration in large trees growing in CO2-enriched atmospheres.

Temperature acclimation of respiration and photosynthesis in the brown algaLaminaria saccharina

Sporophytes of the brown algaLaminaria saccharina (L.) Lamour grown at 15°C contained significantly more chlorophylla (chla) than did similar plants grown at 5°C. The increase in chla in 15°C plants was due to increased numbers of photosystem II reaction centes, and possibly to increased photosynthetic unit size, compared with 5°C plants. These changes were associated with increasedα values (photosynthetic efficiencies) in 15°C-grownL. saccharina relative to 5°C-grown plants. The changes inα together with reduced respiration rates allowed 15°C-grownL. saccharina to achieve net photosynthesis and light-saturated photosynthesis at a lower photon fluence rate (PFR) than 5°C plants when both groups were assayed at the same temperature (15°C). The photon fluence rates necessary to reach the compensation point and achieve light-saturated photosynthesis (I c andI k , respectively) increased with increasing incubation temperature inL. saccharina grown at both 5 and 15°C. However, acclimation responses to growth temperature compensated for the short-term effect of temperature onI c andI k . Consequently, plants grown at 5 and 15°C were able to achieve similar rates of light-limited photosynthesis, and similarI c andI k values at their respective growth temperatures. These responses are undoubtedly important for perennial seaweeds such asL. saccharina, which frequently grow in light-limited habitats and experience pronounced seasonal changes in water temperature.

Absence of respiratory acclimation to diurnally-cycling temperature conditions in rainbow trout

Abstract 1. 1.Oxygen consumption and several ventilatory and cardiac functions were measured in rainbow trout normoxically acclimated to constant temperature conditions (2°, 10°, 18°C) or to a diurnal sinewave temperature cycle (10±4°C). The former groups were also exposed to a single ±4°C cycle. 2. 2.No evidence of diurnal variation in respiratory activity was apparent, and this probably reflects the sampling schedule employed rather than absence of circadian rhythmicity. 3. 3.Temperature related increases in oxygen consumption were closely correlated with increases in ventilatory rate, flow and stroke volume. The latter were associated with increases in pressure generation by buccal and opercular pumps. 4. 4.Heart rate increased with temperature, and electrocardiogram records suggest that this may have been accompanied by increased cardiac output. 5. 5.Enhanced oxygen utilization at higher temperature may stem from lamellar flow adjustments leacling to increases in effective branchial area. 6. 6.There was no evidence of acclimation to cycling temperature conditions per se.

Seasonal variation in two species of unionid clams from Manitoba, Canada: respiration

Respiration is proportional to the 0.769 power of dry weight for Anodonta grandis and the 0.898 power of dry weight for Lampsilis radiata at all temperatures and in all months tested. The log of oxygen consumption increases linearly with temperature for both species up to 24 °C. Q10 values are high but show no season-, temperature-, or size-related relationships. There is no evidence of seasonal acclimation of respiration in either species.

Photosynthetic and Respiratory Acclimation to Temperature in Ledum groenlandicum Populations

Temperature-related photosynthetic and respiratory acclimation responses were examined in alpine, subarctic, and bog populations of Ledum groenlandicum Oeder, a widespread ericaceous shrub species. Acclimation responses to temperature were measured both after 12- to 16-week exposures to either cool (15? C light - 10?C dark) or warm (30?C light - 25?C dark) thermal regimes and again after each of a series of 2-week exposures to new thermal regimes. Dark respiratory rates were decreased by warm acclimation and increased by cool acclimation. These shifts in rates were frequently completed within 2 weeks in a new thermal regime. Maximal net photosynthetic rates generally did not differ significantly among either populations or thermal regimes; however, the temperature for maximal net photosynthesis in each population was increased to 25?C by warm acclimation and decreased to 20?C by cool acclimation. Net photosynthetic rates were increased at cool temperatures by cool acclimation and increased at warm temperatures by warm acclimation. In contrast to respiratory responses, these photosynthetic acclimation shifts were not completed within 2 weeks in a new thermal regime. Ledum groenlandicum populations differed markedly in their potentials for net photosynthetic and dark respiratory acclimation. Alpine and subarctic populations acclimated to greater degrees than their continental and maritime bog counterparts.

Respiratory Acclimation of Phleum alpinum and Sitanion hystrix

Respiratory Acclimation of Phleum alpinum and Sitanion hystrix

The effect of body size and temperature on the respiration of Polinices duplicatus

1. 1. Although variable, respiration is proportional to the 0·536 power of wet weight for Polinices duplicatus at all temperatures and seasons tested. 2. 2. Q 10 is inversely proportional to size between 15 and 30°C and directly porportional to size between 5 and 10°C. 3. 3. Level of metabolism is directly proportional to temperature. 4. 4. Crawling activity is 35 per cent less between 5 and 10°C than between 15 and 30°C. 5. 5. There is no evidence of seasonal acclimation of respiration in P. duplicatus. 6. 6. Possible adaptive significance and physiological mechanisms for patterns of respiration found, and the possibility of a metabolic “switch” are discussed.

Intraspecific Differences in Temperature‐Induced Respiratory Acclimation of Desert Saltbush

Following preconditioning to three temperature regimes (5°—16°C, 21°—32°C, 32°—43°C), dark respiration was measured over a 35°C range in three geographically isolated populations of Atriplex polycarpa (Torr.) S. Wats. Intraspecific differences in carbon dioxide exchange were found which correlated with the climate of the area of origin of the population.

Temperature acclimation of respiration in Culex pipiens pipiens (Diptera: Culicidae) and the influence of seasonal selection

1. 1. Larvae of Culex pipiens pipiens are capable of adaptive acclimation to temperature. The pattern of acclimation changes with age. Few other insects are known to have this ability, even though it is common in other poikilotherms. 2. 2. Temperature compensation (metabolic rate independence from temperature change) occurs outside the acclimation range. Its interaction with acclimation permits homeostasis over a wider range of temperatures than either process alone. Temperature compensation also changes with age. 3. 3. The data indicate that seasonal selection is responsible for a changing response to temperature. The continual interaction of changing environment and responses to selective forces results in a population whose members cannot adaptively respond physiologically to a wide range of conditions. Nevertheless, the response of the population itself shifts adaptively.

Respiratory Function and Thermal Acclimation in Tropical Invertebrates

IT has been reported1 that some cold blooded animals show an increased respiratory quotient when exposed to high temperatures. We have investigated this phenomenon and other aspects of exposure to higher temperatures in connexion with thermal acclimation in molluscs and arthropods. Among the Mollusca we have used two species of Gastropoda common in the irrigation canals of the cotton growing country near Khartoum, both of them vectors of bilharzia; they are Biomphalaria pfeifferi (Dunker) and Bulanus truncatus (Audouin). Crustacea were represented by the terrestrial woodlice (Isopoda) Periscyphis jannonei Arcangeli and Metoponorthus pruinosus (Brandt), insects by the day-active desert beetle Adesmia antiqua Klug and by the night-active desert beetle Ocnera hispida Forskal, and arachnids by the scorpion Leiurus quinquestriatus (Hemprich and Ehrenberg), and by the camel spider (Solifugae) Galeodes grantae Pocock. In the latter two species juvenile animals were used; the others were adults. The snails and wood-lice were supplied with food at all times except when the measurements were being taken; the beetles and arachnids, which can survive more than 6 months' starvation in the laboratory, were unfed. Measurements were made on individual animals after acclimation first at 20° C and then at 34° C, each for 48 h, measurements being made at the same two temperatures by Warburg manometry. It was thus possible to compare the effects of acclimation with these two temperatures in measurements made on the same individuals.

Some Haematological Responses to Sublethal Thermal Shock in the Goldfish, Carassius auratus L.

Red cell numbers and haematocrit values were notable principally for their constancy during a 10-day experimental period following the exposure of goldfish acclimated to 20 C to an abrupt increase of 10 C in environmental temperature. Mean erythrocytic volume underwent a transient decrease while total blood iron (and presumably haemoglobin) and mean erythrocytic iron content fell slightly during the latter portion of the period of observation. Goldfish maintained at 5 C were typically characterized by two haemoglobin polymorphs, a third fraction being commonly found in animals acclimated at 12, 20, and 30 C. The observations are discussed in relation to the respiratory acclimation of this species to increases in environmental temperature.

Non-genetic adaptation to temperature and salinity

Non-genetic adaptation to temperature and salinity

Stoffwechselreaktionen süßwasserlebender Sonnenbarsche auf jahreszeitliche Photoperioden und Temperaturen

1. Metabolic compensations by pumpkinseed sunfish,Lepomis gibbosus, to photoperiods of 9 and 15 hours and to acclimation temperatures ranging between 5° and 25° C have been examined. Respiration rates of whole fish, their brain, gill and muscle tissues, and opercular frequencies were used as indices of adaptation. Techniques for the determination of respiration rates and opercular frequencies have been outlined and discussed. 2. A range in thermal homeostasis has been found forL. gibbosus over which thermal acclimation of respiration is nearly perfect (Q 10 about 1), but which is modifiable by alterations in day length above 10° C. Although less obvious, a relative thermal homeostasis has been detected for opercular frequency as well. Perfection of acclimation appears to be best with both indices in the groups of sunfish which have been adapted to the 15-hour photoperiod. 3. Significant differences in rates of respiration, but not in opercular frequencies, have been observed between the long and short-day groups of fall and winter sunfish above 10° C. During spring and with sunfish in breeding condition, these differences were not detected. Both short and long-day fish showed the same higher level of respiration found to be related to short photoperiod adaptation (9 hrs.). It is suggested that the photoperiodic effect of inducing changes in metabolic rates, most directly relates to some process of conditioning the fish for their primary biological function, reproduction. 4. Because the characteristics and photoperiod sensitivity of metabolic compensations for temperature byL. gibbosus are not apparent below 10° C, this temperature is considered to be critical ecologically for the species in western Massachusetts. The existence of a lower critical temperature for thermal homeostasis of metabolic functions (capacity adaptation) in sunfish is stressed because of its potential as a sensitive indicator of physiological variations for climate and latitude. 5. No indications of compensation for photoperiod (9 and 15 hrs.) and temperatures (7.5° and 20° C) have been detected in the respiration of brain and gill tissues ofL. gibbosus at 25° C except after uncoupling with dinitrophenol. The response of brain respiration with the drug appears to be greatest in sunfish adapted to a 9-hour day and 20° C. In contrast, the dinitrophenol effect upon respiratory change of gill filaments appears to be reversed with respect to the thermal history of the donor fish (highest with acclimation to 7.5° C), but unrelated to the length of the adaptation photoperiod. It is apparent that metabolic systems in different tissues of the same animal or the same tissues in different species, contrast greatly in compensatory responses to temperature and photoperiod. Therefore, the suggestion is offered that the resultant of systemic integration often may be more significantly reflected in responses of whole fishes to changing environmental factors than the possible direct effects of temperature sometimes seen in isolated tissues.