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1.
Different cultivars of wheat (Triticum aestivum L.) were grownin cabinets, under a 12 h photoperiod, at constant temperatures,and high day/low night and low day/high night temperatures.Plants were also transferred at different ages, between 18/10°C and 10/18 °C regimes. Application of the growth regulatorsCCC and TIBA was tested at 18/10 °C and GA3 and IAA at 10/18°C. The reversal of day and night temperatures did not affect spikedifferentiation or the numbers of leaves and elongating internodes.However, tillering and tiller development were markedly promotedby the low day/high night temperature regimes whereas the elongationof leaf blades and stem internodes were suppressed under theseregimes. These effects were attributed to the effects of thetemperature regimes on the endogenous hormone balance of theplants. Considering the results of the transfer and growth regulatortreatments it was concluded that there were no obligatory associationsamong the number of tillers appearing, their subsequent development,leaf blade length, and stem elongation. It is suggested thatthe study of the physiological mechanisms controlling thesecharacters may benefit from experimentation under reciprocallydiffering day night temperature regimes. 相似文献
2.
Two experiments were conducted to assess the response of cauliflower (Brassica oleracea L. var. botrytis) cv. “Nautilus” F1 hybrid to different constant temperatures after curd initiation by keeping the plants in six different
temperature-controlled glasshouse compartments with heating set point temperatures of 6, 10, 14, 18, 22, and 26 °C (±4 °C)
at the School of Plant Sciences, The University of Reading, UK during winter 1998–1999 and summer 1999. Many of the growth
parameters increased with increasing mean growing temperature up to an optimum temperature and then declined with further
increases in temperature. Therefore, cauliflower’s growth and development after curd initiation could be resolved into linear
or curvilinear function of effective temperatures calculated with optimum temperatures between 19 and 23 °C. It is suggested
that future warmer climates will be beneficial for winter cauliflower production rather than summer cauliflower production. 相似文献
3.
Reproduction and population parameters of the Nearctic predator Geocoris punctipes at constant and varying temperature regimes 下载免费PDF全文
V. H. P. Bueno A. M. Calixto F. C. Montes J. C. van Lenteren 《Journal of Applied Entomology》2016,140(5):323-333
The heteropteran predator Geocoris punctipes (Say) has been used in augmentative biological control since 2000 to control Lepidoptera. However, surprisingly, few data are available about the influence of temperature on its population development, which is of key importance to plan the number and moment of releases to obtain sufficient pest reduction. The objective of this study was to evaluate daily and total fecundity, longevity and life table parameters (mx, lx, rm, R, λ, T and TD) of G. punctipes at constant (16.8°C, 21.5°C, 24.5°C and 28.3°C) and corresponding varying (day/night) (21/11°C, 24/18°C, 27/21°C and 30/26°C) temperatures. Pairs of adult predators aged 24 h and originating from nymphs exposed to the same temperature regimes were kept at the above‐mentioned temperature regimes in Petri dishes containing Anagasta kuehniella (Zeller) eggs and an oviposition substrate. Tests were conducted in climatic chambers at the different temperature regimes and a RH 70 ± 10% and a 14L: 10D photoperiod. Reproduction, longevity and life table parameters were significantly affected by temperature, with clear differences between treatments at low (16.8°C, 21/11°C, 21.5°C, 24/18°C) or a high (24.5°C, 27/21°C, 28.3°C, 30/26°C) temperature regimes. Highest reproduction and fastest population growth of G. punctipes took place at average temperatures ranging from 24.5°C to 30°C, and neither reproduction nor population growth was negatively influenced by varying temperatures at any of the temperature regimes. 相似文献
4.
Rising sea temperatures may potentially affect the dispersive larval phase of sessile marine invertebrates with consequences
for the viability of adult populations. This study demonstrated that the planktonic larvae of Rhopaloeides odorabile, a common Great Barrier Reef sponge, survived and metamorphosed when exposed to temperatures up to 9°C above the annual maximum
(~29°C). Planktonic larval duration of 54 h, at ambient temperatures (~28°C), were reduced to 18 h for larvae exposed to elevated
temperatures (32–36°C). Moreover, at ambient temperatures larvae began metamorphosing after 12 h, but at 32–36°C this reduced
to only 2 h. Larvae survived and could still metamorphose at temperatures as high as 38°C, but were no longer functional at
40°C. These results imply that predicted increases in sea surface temperature may reduce planktonic larval duration and dispersal
capabilities, thereby contributing to population subdivision of the species. 相似文献
5.
The effects of temperature, 4085 °C, on the permeabilityand germinability of the hard seeds of the pioneer tree Rhusjavanica L. with a fire syndrome were studied. The temperatureeffective for removal of the water-impermeable coat dormancyof the seeds was 55 ± 7·4 °C. With increasingtemperature, shorter exposure became sufficient to render theseeds permeable, but at temperatures above 75 °C, heat impairmentof germinability resulted in less than 60% germinability, evenwith long exposure. The most favourable regimes among thosetested were temperatures of 6575 °C for durationsof 30120 min, which frequently occur on denuded groundduring the midday hours of clear spring or summer days. Rhus javanica L., water-impermeable coat dormancy, seed germination, high temperature 相似文献
6.
A. Sommer B. Klein H. O. Pörtner 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1997,167(1):25-35
Temperature dependent changes in the mode of energy metabolism and in acid-base status were studied in the range from −1.7
to 26 °C in two populations of Arenicola marina collected in summer as well as in winter from intertidal flats of the North Sea (boreal) and the White Sea (subpolar). Extreme
temperatures led to an accumulation of anaerobic end products, indicating the existence of both a low and a high critical
temperature, beyond which anaerobic metabolism becomes involved in energy production. In summer animals from the North Sea
the high critical temperature was found at temperatures above 20 °C, and the low critical temperature below 5 °C. Latitudinal
or seasonal cold adaptation lead to a more or less parallel shift of both high and low critical temperature values to lower
values. Between critical temperatures intracellular pH declined with rising temperature. Slopes varied between −0.012 and
−0.022 pH- units/°C. In summer animals from the North Sea, the slope was slightly less than in White Sea animals, but differences
appeared independent of the season. However, slopes were no longer linear beyond critical temperatures. A drop in intracellular
pH at low temperatures coincided with the accumulation of volatile fatty acids in the body wall tissue of North Sea animals.
A failure of active pHi adjustment is held responsible for the reduced ΔpHi/ΔT at temperatures above the high critical temperature. Extracellular pH was kept constant over the whole temperature range
investigated. The ability of North Sea animals to adapt to temperatures beyond the critical temperature is poor compared to
White Sea specimens. The larger range of temperature fluctuations at the White Sea is seen as a reason for the higher adaptational
capacity of the subpolar animals. A hypothesis is proposed that among other mechanisms critical temperature values are set
by an adjustment of mitochondrial density and thus, aerobic capacity.
Accepted: 20 August 1996 相似文献
7.
Brooke L. Weigel Sadie L. Small Helen D. Berry Megan N. Dethier 《Journal of phycology》2023,59(5):893-907
Warming ocean temperatures have been linked to kelp forest declines worldwide, and elevated temperatures can act synergistically with other local stressors to exacerbate kelp loss. The bull kelp Nereocystis luetkeana is the primary canopy-forming kelp species in the Salish Sea, where it is declining in areas with elevated summer water temperatures and low nutrient concentrations. To determine the interactive effects of these two stressors on microscopic stages of N. luetkeana, we cultured gametophytes and microscopic sporophytes from seven different Salish Sea populations across seven different temperatures (10–22°C) and two nitrogen concentrations. The thermal tolerance of microscopic gametophytes and sporophytes was similar across populations, and high temperatures were more stressful than low nitrogen levels. Additional nitrogen did not improve gametophyte or sporophyte survival at high temperatures. Gametophyte densities were highest between 10 and 16°C and declined sharply at 18°C, and temperatures of 20 and 22°C were lethal. The window for successful sporophyte production was narrower, peaking at 10–14°C. Across all populations, the warmest temperature at which sporophytes were produced was 16 or 18°C, but sporophyte densities were 78% lower at 16°C and 95% lower at 18°C compared to cooler temperatures. In the field, bottom temperatures revealed that the thermal limits of gametophyte growth (18°C) and sporophyte production (16–18°C) were reached during the summer at multiple sites. Prolonged exposure of bull kelp gametophytes to temperatures of 16°C and above could limit reproduction, and therefore recruitment, of adult kelp sporophytes. 相似文献
8.
In coastal waters, Antarctic rhodophytes are exposed to harsh environmental conditions throughout the year, like low water
temperatures ranging from −1.8°C to 2°C and high light during the summer season. Photosynthetic performance under these conditions
may be affected by slowed down enzymatic reactions and the increased generation of reactive oxygen species. The consequence
might be a chronic photoinhibition of photosynthetic primary reactions related to increased fragmentation of the D1 reaction
centre protein in photosystem II. It is hypothesized that changes in lipid composition of biomembranes may represent an adaptive
trait to maintain D1 turnover in response to temperature variation. The interactive effects of high light and low temperature
were studied on an endemic Antarctic red alga, Palmaria decipiens, sampled from two shore levels, intertidal and subtidal, and exposed to mesocosm experiments using two levels of natural
solar radiation and two different temperature regimes (2–5°C and 5–10°C). During the experimental period of 23 days, maximum
quantum yield of photosynthesis decreased in all treatments, with the intertidal specimens exposed at 5–10°C being most affected.
On the pigment level, a decreasing ratio of phycobiliproteins to chlorophyll a was found in all treatments. A pronounced decrease
in D1 protein concentration occurred in subtidal specimens exposed at 2–5°C. Marked changes in lipid composition, i.e. the
ratio of saturated to unsaturated fatty acids, indicated an effective response of specimens to temperature change. Results
provide new insights into mechanisms of stress adaptation in this key species of shallow Antarctic benthic communities. 相似文献
9.
Supercooling points, lower lethal temperatures, and the effect of short-term exposures to low temperatures were examined
during both winter and summer in the adults of six weevil species from three different habitats on Marion Island. Upper lethal
limits and the effects of short-term exposure to high temperatures were also examined in summer-acclimatized adult individuals
of these species. Bothrometopus elongatus, B. parvulus, B. randi, Ectemnorhinus marioni, and E. similis were freeze tolerant, but had high lower lethal temperatures (−7 to −10°C). Seasonal variation in these parameters was not
pronounced. Physical conditions of the habitat appeared to have little effect on cold hardiness parameters because the Ectemnorhinus species occur in very wet habitats, whereas the Bothrometopus species inhabit drier areas. The adults of these weevil species are similar to other high southern latitude insects in that
they are freeze tolerant, but with high lower lethal temperatures. In contrast, Palirhoeus eatoni, a supra-littoral species, avoided freezing and had a mean supercooling point of −15.5 ± 0.94°C (SE) in winter and −11.8 ± 0.98°C
in summer. Survival of a constant low temperature of −8°C also increased in this species from 6 h in summer to 27 h in winter.
It is suggested that this strategy may be a consequence of the osmoregulatory requirements imposed on this species by its
supra-littoral habitat. Upper lethal temperatures (31–34°C) corresponded closely with maximum microclimate temperatures in
all of the species. This indicates that the pronounced warming, accompanied by the increased insolation that has been recorded
at Marion Island, may reduce survival of these species. These effects may be compounded as a consequence of predation by feral
house mice on the weevils.
Received: 4 February 1997 / Accepted: 3 May 1997 相似文献
10.
Agnieszka I. Piotrowicz-Cielak 《Acta Physiologiae Plantarum》2006,28(4):349-356
The objective of this paper was to compare the levels of soluble sugars in seeds of yellow lupin cv. Juno matured at different
temperatures. The temperature regimes applied were 1). 26 °C for 24 h (high temperature), 2). 24 °C for 12 h and 19 °C for
the next 12 h (optimum temperature regime), 3). 26 °C for 16 h and 4 °C for the next 8 h (high-low temperatures). Six soluble
carbohydrates (d-galactose, myo-inositol, sucrose, raffinose, stachyose and verbascose) were quantified. Seeds maturing at constant temperature 26 °C accumulated
more raffinose (by 100 %) than seeds maturing at optimum temperature regime. Seeds maturing at high temperature accumulated
less stachyose and verbascose than those maturing at optimum temperature conditions, the differences being 45 and 24 %, respectively.
In seeds maturing at high-low temperature the level of raffinose decreased while the level of stachyose and verbascose increased,
compared to those maturing at optimum conditions. The contents of sucrose, d-galactose and myo-inositol in seeds maturing at optimum temperatures was lower than in seeds maturing at both high and high-low temperature
regimes. It was shown, that temperature conditions — constant high temperature, or physiologically optimal thermal oscillations
(24 °/19 °C) or high-low temperature regime — differently affect the contents of six soluble carbohydrates in maturing seeds
of yellow lupin. 相似文献
11.
To understand the influence of temperature on host–parasitoid interactions as a consequence of climatic change, we studied
development, survival, and fecundity of field and laboratory strains of the Helicoverpa armigera larval endoparasitoid, Campoletis chlorideae at five different temperatures under laboratory conditions. Post-embryonic development period and degree-days required for
completing the life cycle by both the strains decreased by 2.5 and 1.5 folds at 27°C compared to 18°C. Post embryonic development
period showed a negative (r = −0.99, P < 0.001) and the development rate a positive (r = 0.99, P < 0.001) association with an increase in temperature. However, no parasitoid larvae survived in H. armigera larvae reared at 12 and 35°C after parasitization, suggesting that temperatures ≥35°C as a result of global warming will
be lethal for development and survival of immature stages of C. chlorideae. Adult longevity was negatively associated (r = −0.91 to −0.96, P < 0.001) with temperatures between 12 and 35°C. The parasitoid adults stored at 12°C survived for longer period and exhibited
higher fecundity than those kept at 27°C, but the efficiency of parasitism and adult emergence were quite low. Sex ratio of
the progeny at 12°C was highly male-biased than the insects kept at 27°C. Laboratory strain of the parasitoid exhibited better
survival, and the adults lived longer than the field strain at 18°C than at 27°C. Therefore, C. chlorideae adults stored at 18°C could be used for parasitism, while the immature stages should be reared at 27°C for mass production
of the parasitoid for biological control of H. armigera. 相似文献
12.
In this study we determined oil degradation rates in the North Sea under most natural conditions. We used the heavy fuel oil,
Bunker C, the major oil pollutant of the North Sea, as the model oil. Experiments were conducted in closed systems with water
sampled during winter and repeated under identical conditions with water collected during summer. No nitrogen or phosphorous
was added and conditions were chosen such that neither oxygen nor nutrients, present in the water, would become limiting during
the experiments. We detected a fourfold increased degradation rate for water samples taken in summer (18°C water temperature)
as compared to water sampled in winter (4°C water temperature). Under the assumption that biodegradation of oil can be regarded
as a Michaelis-Menten type kinetic reaction, the kinectic constants Vmax and KM were determined for oil biodegradation at 4°C and 18°C. At both temperatures KM was about 40 ppm, whereas Vmax was 3–4 times higher at 18°C. From both Vmax and the results of fermentation studies, we determined the maximum rates of Bunker C oil degradation in the North Sea as
∼20 g m−3a−1 at 4°C in winter and 60–80 g m−3a−1 at 18°C in summer. Furthermore, while over 25% of the oil was degraded within 6 weeks in summer, only 6.6% of the oil was
degraded in winter. A higher incubation temperature in winter (18°C) increased both the rate and the percentage of oil degraded,
but degradation did not reach the level obtained during the summer. While these data reflect the oxidation only of the hydrocarbons,
we conducted experiments directly in the open sea to determine the contribution of abiotic factors to oil removal. Approximately
42% of the oil was lost within 6 weeks under these conditions in summer and 65% in winter. However, GC-MS analysis of the
recovered oil showed no significant change in the alkane pattern that would indicate enhanced degradation. Thus, mainly abiotic
factors such as erosion and dispersion rather than degradation were responsible for enhanced oil removal. Especially the high
loss during winter can be attributed to frequent storms resulting in greater dispersion. In conclusion, the higher oil degrading
potential of the microbial population in the North Sea was represented by a four times faster oil degradation during the summer.
In-situ experiments showed that abiotic factors can have an equal (summer) or even higher (winter) impact on oil removal. 相似文献
13.
Jeffrey R. Ziegeweid Cecil A. Jennings Douglas L. Peterson 《Environmental Biology of Fishes》2008,82(3):299-307
Many populations of shortnose sturgeon, Acipenser brevirostrum, in the southeastern United States continue to suffer from poor juvenile recruitment. High summer water temperatures, which
may be exacerbated by anthropogenic activities, are thought to affect recruitment by limiting available summer habitat. However,
information regarding temperature thresholds of shortnose sturgeon is limited. In this study, the thermal maximum method and
a heating rate of 0.1°C min−1 was used to determine critical and lethal thermal maxima for young-of-the-year (YOY) shortnose sturgeon acclimated to temperatures
of 19.5 and 24.1°C. Fish used in the experiment were 0.6 to 35.0 g in weight and 64 to 140 days post hatch (dph) in age. Critical
thermal maxima were 33.7°C (±0.3) and 35.1°C (±0.2) for fish acclimated to 19.5 and 24.1°C, respectively. Critical thermal
maxima significantly increased with an increase in acclimation temperature (p < 0.0001). Lethal thermal maxima were 34.8°C (±0.1) and 36.1°C (±0.1) for fish acclimated to 19.5 and 24.1°C, respectively.
Lethal thermal maxima were significantly affected by acclimation temperature, the log10 (fish weight), and the interaction between log10(fish weight) and acclimation temperature (p < 0.0001). Thermal maxima were used to estimate upper limits of safe temperature, thermal preferences, and optimal growth
temperatures of YOY shortnose sturgeon. Upper limits of safe temperature were similar to previous temperature tolerance information
and indicate that summer temperatures in southeastern rivers may be lethal to YOY shortnose sturgeon if suitable thermal refuge
cannot be found. 相似文献
14.
Understanding environmental drivers of black band disease (BBD), a virulent disease affecting corals worldwide, is critical
to managing coral populations. Field monitoring studies have implicated seasonally elevated temperature and light as drivers
of annual BBD outbreaks on the Great Barrier Reef, but do not distinguish their relative impacts. Here, we compare progression
of BBD lesions on Montipora hispida among three controlled temperature (28.0, 29.0, 30.5°C) and two controlled light treatments (170, 440 μmol m−2 s−1) within normal seasonal ranges at the site. BBD progression rates were greatest (5.2 mm d−1) in the 30.5°C/high-light treatment and least (3.2 mm d−1) in the 28°C/low-light treatment. High light significantly enhanced BBD progression, whereas increases in disease progression
under high temperatures were not statistically significant, identifying the greater role of light in driving BBD dynamics
within the temperature range examined. Greater BBD progression during daytime compared with nighttime (by 2.2–3.6-fold across
temperature and light treatments) corroborates our conclusion that light is the pre-eminent factor driving BBD progression
at typical summer temperatures. Decreased photochemical efficiency of algal endosymbionts in the high-temperature/high-light
treatments suggests that compromised health of the coral holobiont contributes to enhanced disease progression, highlighting
the complexity of disease dynamics in host–pathogen systems responding to environmental changes. 相似文献
15.
Germination responses ofMallotus japonicus (Thumb). Muell. Arg. seeds to temperature revealed a gap-detecting mechanism in the seed germination of the species. Among
various constant and alternating temperatures examined in the range from 12–40°C, only very limited temperature regimes were
found to be favourable for seed germination, specifically, alternating temperatures between 18–32°C and 28–40°C. A single
several-hour higher-temperature (32–40°C) treatment could also induce the germination of seeds which had been imbibed for
several days at a constant temperature in the range of 20–26°C, suggesting that there is a process requiring higher temperature
among the overal germination processes. Seeds located at or near the surface of denuded soil would have a good chance of experiencing
such a temperature change when several rainy days are followed by fine weather, while seeds beneath close vegetation would
not. On the other hand, the pressence or absence of light or a simulated ‘canopy ligh’ had little effect on the germination.
Therefore, it was concluded that the seeds ofM. japonicus have a ‘gapdetecting mechanism’ in the form of a higher-temperature requirement of a certain process involved in the overall
germination processes. 相似文献
16.
Animal responses to changing environments are most commonly studied in relation to temperature change. The current paradigm
for marine ectotherms is that temperature limits are set through oxygen limitation. Oxygen limitation leads to progressive
reductions in capacity to perform work or activity, and these are more important and proximate measures of a population’s
ability to survive. Here we measured the ability of a large Antarctic clam to rebury when removed from sediment at temperatures
between −1.5 and 7.5 °C and at three oxygen concentrations, 10.2, 20.5 and 27.7%. The proportion of the population capable
of reburying declined rapidly and linearly with temperature from around 65% at 0 °C to 0% at 6 °C in normoxia (20.5% O2). Decreasing oxygen to 10.2% reduced temperature limits for successful burial by around 2 °C, and increasing oxygen to 27.7%
raised the limits by 1–1.5 °C. There was an interactive effect of body size and temperature on burying: the temperature limits
of larger individuals were lower than smaller animals. Similarly, these size limits were increased by increasing oxygen availability.
Considering data for all temperatures and oxygen levels, the fastest burying rates occurred at 3 °C, which is 2 °C above the
maximum summer temperature at this site. 相似文献
17.
The final preferable temperature (FPT) and avoidance temperature (AT) were determined in parthenogenetic females of the crustacean
Daphnia magna Strauss. The animals were preliminary acclimated to constant temperature of 23.4°C followed by keeping them in a thermo-gradient
device for 24 days. It was revealed that daphnia select FPT with overshoot. In the first four days, daphnia selected temperatures
0.6–1.6°C higher than the acclimation temperature and 4–7.4°C higher than FPT. Two zones of FPT are revealed: the first zone
by the time of 5–13 days (17.6 ± 1.2°C); the second, by 16–24 days (20 ± 1.5°C). The dynamics of AT diapason followed the
dynamics of FPT. Two zones of the AT plateau were observed: over five to 17 days (temperatures <14°C and >25.8°C were avoided)
and for 21–24 days (<8.5°C and >26°C). 相似文献
18.
The germination of cassava seed in response to various constantand alternating temperature regimes within the range 1940°C was investigated using a two-dimensional temperaturegradient plate. It was found that almost all seeds were incapableof germination unless the temperature for part of the day exceeded30 °C and the mean temperature was at least 24 °C. However,dormant seeds required environments where the temperature forpart of the day exceeded 36 °C, the mean temperature wasat least 33 °C, and the amplitude of the diurnal temperaturealteration was within the range 318 °C. Providingthese conditions were met, the times spent at the upper andlower temperatures within a diurnal cycle were not critical.Hermetic storage of the seed for 77 days at 40 °C with 7.9per cent moisture content did not influence the pattern of germinationin response to constant and alternating temperatures. It issuggested that an alternating temperature regime of 30 °Cfor 8 h/38 °C for 16 h applied for a minimum of 21 daysis appropriate for cassava seed viability tests. Manihot esculenta Crantz, cassava, germination, dormancy, temperature 相似文献
19.
K. Nakamura Masatoshi Tanaka Yutaka Motohashi Akira Maeda 《International journal of biometeorology》1997,40(2):103-106
This study was conducted to clarify the seasonal difference in body temperature in summer and winter, and to document the
thermal environment of the elderly living in nursing homes. The subjects were 57 healthy elderly people aged ≥63 years living
in two nursing homes in Japan. One of the homes was characterized by subjects with low levels of activities of daily living
(ADL). Oral temperatures were measured in the morning and afternoon, with simultaneous recording of ambient temperature and
relative humidity. Oral temperatures in summer were higher than in winter, with statistically significant differences (P<0.05) of 0.25 (SD 0.61) °C in the morning and 0.24 (SD 0.50) °C in the afternoon. Differences between oral temperatures in
summer and winter tended to be greater in subjects with low ADL scores, even when their room temperature was well-controlled.
In conclusion, the oral temperatures of the elderly are lower in winter than summer, particularly in physically inactive people.
It appears that those with low levels of ADL are more vulnerable to large changes in ambient temperature.
Received: 28 March 1996 / Accepted: 12 November 1996 相似文献
20.
The success of P. juliflora, an evergreen woody species has been largely attributed to temperature acclimation and stomatal control of photosynthesis
under wide range of environmental conditions prevalent in India. We studied the contribution of the enzyme ribulose-1,5 bisphosphate
carboxylase/oxygenase (Rubisco) in diurnal and seasonal photosynthesis changes in P. juliflora. The changes observed in photosynthesis under natural conditions could be effected by the growth temperatures, which ranged
from 10–30 °C in winter to 30–47 °C in summer. However, the Total Rubisco activity displayed a constant diurnal pattern and
showed a maximum at 1200 in all seasons namely spring, summer, monsoon and winter irrespective of the changes in temperature.
The Total Rubisco activity from two cohorts of leaves produced in spring and monsoon appeared to be down-regulated differentially
at low PPFD during the evening. The in vivo and in vitro measurements of carboxylation efficiency of Rubisco showed wide variation during the day and were correlated with the photosynthesis
rate. The light activation of Rubisco showed the acclimation to moderately high temperatures in different seasons except in
summer. The exceptionally high temperatures (>45 °C) in summer, though not affecting Total activity, severely inhibited the
light activation of Rubisco and also modulated the recovery process for the activation of Rubisco. Our studies suggest that
the modulation of Rubisco driven by Rubisco activase and not Rubisco per se was crucial for the diurnal regulation of photosynthesis.
NBRI Publication No.: 528 相似文献