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1.
Photosynthetic acclimation to elevated CO2 in wheat cultivars 总被引:2,自引:0,他引:2
Wheat (T. aestivum) cvs. Kalyansona and Kundan grown under atmospheric (CA) and elevated CO2 concentrations (650±50 cm3 m-3 - CE) in open top chambers were examined for net photosynthetic rate (PN), stomatal limitation (l
s) of P
N, ribulose-1,5-bisphosphate carboxylase (RuBPC) activity, and saccharide content of the leaves. The P
N values of both CA- and CE-grown plants compared at the same CO2 concentration showed a down regulation under CE at the post-anthesis stage. The negative acclimation of P
N appeared to be due to both stomatal and mesophyll components, and the RuBPC activity got also adjusted. There was a decrease
in activation state of RuBPC under CE. In connection with this, an increased accumulation of saccharides in wheat leaf under
CE was observed. Kalyansona, owing to its larger sink potential in terms of the number of grains, showed a greater enhancement
under CE in both post-ear emergence dry matter production and grain yield. Under CE, this cultivar also showed a lower down
regulation of P
N than Kundan.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
2.
Wheat (T. aestivum) cvs. Kalyansona and Kundan grown under atmospheric (CA) and elevated CO2 concentrations (650±50 cm3 m-3 - CE) in open top chambers were examined for net photosynthetic rate (PN), stomatal limitation (l s) of P N, ribulose-1,5-bisphosphate carboxylase (RuBPC) activity, and saccharide content of the leaves. The P N values of both CA- and CE-grown plants compared at the same CO2 concentration showed a down regulation under CE at the post-anthesis stage. The negative acclimation of P N appeared to be due to both stomatal and mesophyll components, and the RuBPC activity got also adjusted. There was a decrease in activation state of RuBPC under CE. In connection with this, an increased accumulation of saccharides in wheat leaf under CE was observed. Kalyansona, owing to its larger sink potential in terms of the number of grains, showed a greater enhancement under CE in both post-ear emergence dry matter production and grain yield. Under CE, this cultivar also showed a lower down regulation of P N than Kundan. 相似文献
3.
Photosynthetic acclimation to elevated CO2 in a sunflower canopy 总被引:3,自引:0,他引:3
Sunflower canopies were grown in mesocosom gas exchange chambers at ambient
and elevated CO2 concentrations (360 and 700 ppm) and leaf photosynthetic
capacities measured at several depths within each canopy. Elevated [CO2]
had little effect on whole-canopy photosynthetic capacity and total leaf
area, but had marked effects on the distribution of photosynthetic capacity
and leaf area within the canopy. Elevated [CO2] did not significantly
reduce the photosynthetic capacities per unit leaf area of young leaves at
the top of the canopy, but it did reduce the photosynthetic capacities of
older leaves by as much as 40%. This effect was not dependent on the canopy
light environment since elevated [CO2] also reduced the photosynthetic
capacities of older leaves exposed to full sun on the south edge of the
canopy. In addition to the effects on leaf photosynthetic capacity,
elevated [CO2] shifted the distribution of leaf area within the canopy so
that more leaf area was concentrated near the top of the canopy. This
change resulted in as much as a 50% reduction in photon flux density in the
upper portions of the elevated [CO2] canopy relative to the ambient [CO2]
canopy, even though there was no significant difference in the total canopy
leaf area. This reduction in PFD appeared to account for leaf carbohydrate
contents that were actually lower for many of the shaded leaves in the
elevated as opposed to the ambient [CO2] canopy. Photosynthetic capacities
were not significantly correlated with any of the individual leaf
carbohydrate contents. However, there was a strong negative correlation
between photosynthetic capacity and the ratio of hexose sugars to sucrose,
consistent with the hypothesis that sucrose cycling is a component of the
biochemical signalling pathway controlling photosynthetic acclimation to
elevated [CO2]. 相似文献
4.
3种落叶松幼苗对CO2升高的光合生理响应 总被引:1,自引:0,他引:1
采用Li-6400便携式光合作用测定系统研究CO2升高对长白落叶松(Larix olgensisHerry.),日本落叶松(Larix kaempferiCarr.)和兴安落叶松(LarixgmeliniRupr.)当年生和1年生幼苗的光合特性的影响。结果表明:CO2升高使3种落叶松光饱和光合速率(Pmax)和呼吸速率均有不同程度的增加,其中,长白落叶松当年生和1年生幼苗Pmax分别比对照提高了91%和83%,日本落叶松当年生和1年生幼苗Pmax分别比对照提高了71%和94%,而兴安落叶松当年生和1年生幼苗Pmax分别比对照提高了32%和106%。除兴安落叶松外,CO2升高使所有落叶松当年生幼苗的光补偿点(LCP)下降,说明当年生幼苗对CO2浓度升高的反应更敏感。CO2升高使日本落叶松当年生和1年生幼苗光饱和点(LSP)都升高,反映了其光合作用提高的潜力较大。CO2升高条件下,除1年生兴安落叶松外,其他处理的落叶松最大量子效率(AQYmax)均增加。比较分析表明,在未来大气CO2浓度升高条件下,日本落叶松的生长潜能可能最大,具有较强的生态优势,长白落叶松次之,兴安落叶松最小。 相似文献
5.
Summary Six early successional plant species with differing photosynthetic pathways (3 C3 species and 3 C4 species) were grown at either 300, 600, or 1,200 ppm CO2 and at either 0.0 or 0.25 ppm SO2. Total plant growth increased with CO2 concentration for the C3 species and varied only slightly with CO2 for the C4 species. Fumigation with SO2 caused reduced growth of the C3 species at 300 ppm CO2 but not at the higher concentrations of CO2. Fumigation with SO2 reduced growth of the C4 species at high CO2 and increased growth at 300 ppm CO2. Leaf area increased with increasing CO2 for all plant species. Fumigation with SO2 reduced leaf area of C3 plants more at low CO2 than at high CO2 while leaf area of C4 plants was reduced more at high CO2 than at low CO2. These results support the notion that C3 species are more sensitive to SO2 fumigation than are C4 species at concentrations of CO2 equal to that found in normal ambient air. However, the difference in sensitivity to SO2 between C3 and C4 species was found to be reversed at higher concentrations of CO2. A possible explanation for this reversal based upon differences in stomatal response to elevated CO2 between C3 and C4 species is discussed. 相似文献
6.
7.
The effects of prolonged CO2 enrichment of tomato plants on photosynthetic performance and Calvin cycle enzymes, including the amount and activity of ribulose-1,5-bisphosphate carboxylase (RuBPco), were determined. Also the light-saturated rate of photosynthesis (Pmax) of the 5th leaf throughout leaf development was predicted based on the amount and kinetics of RuBPco. With short-term CO2 enrichment, i.e. only during the photosynthesis measurements, Pmax of the young leaves did not increase while the leaves reaching full expansion more than doubled their net rate of CO2 fixation. However, with longer-term CO2 enrichment, i.e. growing the crop in high CO2, the plants did not maintain this photosynthetic gain. Compared with leaves of plants grown in normal ambient CO2 the high CO2-grown leaves, when almost fully expanded, contained only about half as much RuBPco protein and Pmax in 300 and 1000 vpm CO2 was similarly reduced.The loss of RuBPco protein may be a factor associated with the accelerated fall in Pmax since Pmax was close to that predicted from the amount and kinetics of RuBPco assuming RuBP saturation. Acclimation to high CO2 is fundamentally different from acclimation to high light. In contrast to acclimation to high light, acclimation to high CO2 does not usually involve an increase in photosynthetic machinery so the synthesis and maintenance costs (as indicated by the dark respiration rate) are generally lower. 相似文献
8.
During the past 25 Myr, partial pressures of atmospheric CO2 (Ca) imposed a greater limitation on C3 than C4 photosynthesis. This could have important downstream consequences for plant nitrogen economy and biomass allocation. Here, we report the first phylogenetically controlled comparison of the integrated effects of subambient Ca on photosynthesis, growth and nitrogen allocation patterns, comparing the C3 and C4 subspecies of Alloteropsis semialata. Plant size decreased more in the C3 than C4 subspecies at low Ca, but nitrogen pool sizes were unchanged, and nitrogen concentrations increased across all plant partitions. The C3, but not C4 subspecies, preferentially allocated biomass to leaves and increased specific leaf area at low Ca. In the C3 subspecies, increased leaf nitrogen was linked to photosynthetic acclimation at the interglacial Ca, mediated via higher photosynthetic capacity combined with greater stomatal conductance. Glacial Ca further increased the biochemical acclimation and nitrogen concentrations in the C3 subspecies, but these were insufficient to maintain photosynthetic rates. In contrast, the C4 subspecies maintained photosynthetic rates, nitrogen‐ and water‐use efficiencies and plant biomass at interglacial and glacial Ca with minimal physiological adjustment. At low Ca, the C4 carbon‐concentrating mechanism therefore offered a significant advantage over the C3 type for carbon acquisition at the whole‐plant scale, apparently mediated via nitrogen economy and water loss. A limiting nutrient supply damped the biomass responses to Ca and increased the C4 advantage across all Ca treatments. Findings highlight the importance of considering leaf responses in the context of the whole plant, and show that carbon limitation may be offset at the expense of greater plant demand for soil resources such as nitrogen and water. Results show that the combined effects of low CO2 and resource limitation benefit C4 plants over C3 plants in glacial–interglacial environments, but that this advantage is lessened under anthropogenic conditions. 相似文献
9.
Photosynthetic acclimation in trees to rising atmospheric CO2: A broader perspective 总被引:10,自引:0,他引:10
Analysis of leaf-level photosynthetic responses of 39 tree species grown in elevated concentrations of atmospheric CO2 indicated an average photosynthetic enhancement of 44% when measured at the growth [CO2]. When photosynthesis was measured at a common ambient [CO2], photosynthesis of plants grown at elevated [CO2] was reduced, on average, 21% relative to ambient-grown trees, but variability was high. The evidence linking photosynthetic acclimation in trees with changes at the biochemical level is examined, along with anatomical and morphological changes in trees that impact leaf- and canopy-level photosynthetic response to CO2 enrichment. Nutrient limitations and variations in sink strength appear to influence photosynthetic acclimation, but the evidence in trees for one predominant factor controlling acclimation is lacking. Regardless of the mechanisms that underlie photosynthetic acclimation, it is doubtful that this response will be complete. A new focus on adjustments to rising [CO2] at canopy, stand, and forest scales is needed to predict ecosystem response to a changing environment.Abbreviations A/Ci
photosynthesis as a function of internal [CO2]
- Jmax
maximum rate of electron transport
- Rubisco
ribulose-1,5-bisphosphate carboxylase/oxygenase
- Vcmax
maximum rate of carboxylation
The U.S. Government right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged. 相似文献
10.
11.
Ceulemans R.; Taylor G.; Bosac C.; Wilkins D.; Besford R.T. 《Journal of experimental botany》1997,48(9):1681-1689
The effects of elevated CO2 were studied on the photosyntheticgas exchange behaviour and leaf physiology of two contrastingpoplar (Populus) hybrids grown and treated in open top chambers(OTCs in Antwerp, Belgium) and in closed glasshouse cabinets(GHCs in Sussex, UK). The CO2 concentrations used in the OTCswere ambient and ambient +350 µmol mol1 while inthe GHCs they were c. 360 µmol mol1 versus 719µmol mol1. Measurements of photosynthetic gas exchangewere made for euramerican and interamerican poplar hybrids incombination with measurements of dark respiration rate and Rubiscoactivity. Significant differences in the leaf anatomy and structure(leaf mass per area and chlorophyll content) were observed betweenthe leaves grown in the OTCs and those grown in the GHCs. ElevatedCO2 stimulated net photosynthesis in the poplar hybrids after1 month in the GHCs and after 4 months in the OTCs, and therewas no evidence of downward acclimation (or down-regulation)of photosynthesis when the plants in the two treatments weremeasured in their growth CO2 concentration. There was also noevidence of down-regulation of Rubisco activity and there wereeven examples of increases in Rubisco activity. Rubisco exerteda strong control over the light-saturated rate of photosynthesis,which was demonstrated by the close agreement between observednet photosynthetic rates and those that were predicted fromRubisco activities and Michaelis-Menten kinetics. After 17 monthsin elevated CO2 in the OTCs there was a significant loss ofRubisco activity for one of the hybrid clones, i.e. Beaupr,but not for clone Robusta. The effect of the CO2 measurementconcentration (i.e. the short-term treatment effect) on netphotosynthesis was always larger than the effect of the growthconcentration in both the OTCs or GHCs (i.e. the longterm growthCO2 effect), with one exception. For the interamerican hybridBeaupr dark respiration rates in the OTCs were not significantlyaffected by the elevated CO2 concentrations. The results suggestthat for rapidly growing tree species, such as poplars, thereis little evidence for downward acclimation of photosynthesiswhen plants are exposed to elevated CO2 for up to 4 months;longer term exposure reveals loss of Rubisco activity. Key words: Elevated CO2, Populus, Rubisco, photosynthesis, chlorophyll content 相似文献
12.
When measured at a same CO(2) concentration, net photosynthetic rate is often significantly lower in long-term high CO(2)-grown plants than the ambient CO(2)-grown ones. This phenomenon is termed photosynthetic acclimation or down-regulation. Although there have been many reports and reviews, the mechanism(s) of the photosynthetic acclimation is not very clear. Combining the work of the authors' group, this paper briefly reviews the progress in studies on the mechanism(s) of the photosynthetic acclimation to elevated CO(2). It is suggested that besides the possible effects of respiration enhancement and excessive photosynthate accumulation, RuBP carboxylation limitation and RuBP regeneration limitation are probably the main factors leading to the photosynthetic acclimation. 相似文献
13.
两种木兰科植物叶片光合作用的光驯化 总被引:6,自引:3,他引:6
测定了生长在全日、54%和21%日光强下需光植物火力楠(Michelia meachurei)和耐荫植物华东拟单性木兰(Parakmerialotungensis)叶片气体交换参数,用以估测降低光强对光合作用的限制和对低光的光驯化.生长在全日光强下火力楠的光饱和光合速率较华东拟单性木兰高.当日光强降低到54%,火力楠叶片光合速率降低幅度较华东拟单性木兰大.当日光降低至21%,华东拟单性木兰的表观量子产率和光能转换率较火力楠高.在全日光强下,火力楠的Vcmax较华东拟单性木兰高.随着日光强降低,两种木兰植物的Vcmax降低,当日光强降低至54%和21%,火力楠的Vcmax降幅较华东拟单性木兰大,火力楠Vcmax对光强降低较华东拟单性木兰敏感.生长光强降低,两种木兰植物内部CO2传导度(gi)降低.在低光强下火力楠仍保持较华东拟单性木兰高的gi.生长光强降低到全日光强的54%,火力楠gi对光合速率限制(Li)与在全日光强的条件下没有区别(p>0.05),表现火力楠gi对54%日光强的驯化;在54%的光条件下,华东拟单性木兰的呼吸速率对光合速率的限制(Lr)与全日光照无差别(p>0.05),显示呼吸速率对低光的驯化.两种木兰植物气孔导度对光合速率的限制(Ls)随光强降低而增大.在遮荫条件下种间叶特性差别明显,这亦反映出两种植物物种光合驯化的差异.火力楠gi对低光驯化,而华东拟单性木兰叶片对较高光强驯化更甚于对低光强. 相似文献
14.
A common observation in plants grown in elevated CO2 concentration is that the rate of photosynthesis is lower than expected from the dependence of photosynthesis upon CO2 concentration in single leaves of plants grown at present CO2 concentration. Furthermore, it has been suggested that this apparent down regulation of photosynthesis may be larger in leaves of plants at low nitrogen supply than at higher nitrogen supply. However, the available data are rather limited and contradictory. In this paper, particular attention is drawn to the way in which whole plant growth response to N supply constitutes a variable sink strength for carbohydrate usage and how this may affect photosynthesis. The need for further studies of the acclimation of photosynthesis at elevated CO2 in leaves of plants whose N supply has resulted in well-defined growth rate and sink activity is emphasised, and brief consideration is made of how this might be achieved.Abbreviations A
rate of CO2 assimilation
- Ci
internal CO2 concentration
- PCR
photosynthetic carbon reduction
- Rubisco
Ribulose 1,5-bisphosphate carboxylase/oxygenase
- RuBP
ribulose 1,5-bisphosphate 相似文献
15.
Elevated atmospheric CO2 is known to stimulate photosynthesis and growth of plants with the C3 pathway but less of plants with the C4 pathway. An increase in the CO2 concentration can therefore be expected to change the competitive interactions between C3 and C4 species. The effect of long term exposure to elevated CO2 (ambient CO2 concentration +340 µmol CO2 mol-1) on a salt marsh vegetation with both C3 and C4 species was investigated. Elevated CO2 increased the biomass of the C3 sedgeScirpus olneyi growing in a pure stand, while the biomass of the C4 grassSpartina patens in a monospecific community was not affected. In the mixed C3/C4 community the C3 sedge showed a very large relative increase in biomass in elevated CO2 while the biomass of the C4 species declined.The C4 grassSpartina patens dominated the higher areas of the salt marsh, while the C3 sedgeScirpus olneyi was most abundant at the lower elevations, and the mixed community occupied intermediate elevations.Scirpus growth may have been restricted by drought and salt stress at the higher elevations, whileSpartina growth at the lower elevations may be affected by the higher frequency of flooding. Elevated CO2 may affect the species distribution in the salt marsh if it allowsScirpus to grow at higher elevations where it in turn may affect the growth ofSpartina. 相似文献
16.
Ian E. Woodrow 《Photosynthesis research》1994,39(3):401-412
A range of studies of C3 plants have shown that there is a change in both the carbon flux and the pattern of nitrogen allocation when plants are grown under enhanced CO2. This paper examines evidence that allocation of nitrogen both to and within the photosynthetic system is optimised with respect to the carbon flux. A model is developed which predicts the optimal relative allocation of nitrogen to key enzymes of the photosynthetic system as a function of CO2 concentration. It is shown that evidence from flux control analysis is broadly consistent with this model, although at high nitrogen and under certain conditions at low nitrogen experimental data are not consistent with the model. Acclimation to enhanced CO2 is also assessed in terms of resource allocation between photosynthate sources and sinks. A means of assessing the optimisation of this source-sink allocation is proposed, and several studies are examined within this framework. It is concluded that C3 plants probably possess the genetic feedback mechanisms required to efficiently smooth out any imbalance within the photosynthetic system caused by a rise in atmospheric CO2.Abbreviations A
net rate of CO2 assimilation
-
c
i
intercellular CO2 concentration
- CR
A
flux control coefficient for Rubisco with respect to flux A
- FBPase
fructose 1,6-bisphosphatase
- kapp
apparent catalytic rate constant
- PCO
photorespiratory carbon oxidation
- PCR
photosynthetic carbon reduction
- PPFD
photosynthetically active photon flux density
- Rubisco
ribulose 1,5-bisphosphate carboxylase/oxygenase
- RuBP
ribulose 1,5-bisphosphate
- Ru5P
ribulose 5-phosphate
- SBPase
sedoheptulose 1,7-bisphosphatase 相似文献
17.
Photosynthetic acclimation to elevated atmospheric carbon dioxide and UV irradiation in Pinus banksiana 总被引:2,自引:0,他引:2
Pinus banksiana seedlings were grown for 9 months in enclosures in greenhouses at CO2 concentrations of 350 or 750 μmol mol−1 with either low (0.005 to 0. 3 W m−2 ) or high (0.25 to 0. 90 W m−2 ) ultraviolet-B (UV-B) irradiances. Total seedling dry weight decreased with high UV treatment but was unaffected by CO2 enrichment. High UV treatment also shifted biomass partitioning in favor of leaf production. Both CO2 and UV treatments decreased the dark respiration rate and light compensation point. High UV light inhibited photosynthesis at 350 but not at 750 μmol mol−1 CO2 due to a UV induced increase in ribulose-1, 5-bisphosphate carboxylase/oxygenase efficiency and ribulose-1, 5-bisphosphate regeneration. Stomatal density was increased by high UV irradiance but was unchanged by CO2 enrichment. 相似文献
18.
Photosynthetic acclimation of maize to growth under elevated levels of carbon dioxide 总被引:4,自引:0,他引:4
The effects of elevated CO2 concentrations on the photochemistry, biochemistry and physiology of C4 photosynthesis were studied in maize (Zea mays L.). Plants were grown at ambient (350 μL L−1) or ca. 3 times ambient (1100 μL L−1) CO2 levels under high light conditions in a greenhouse for 30 d. Relative to plants grown at ambient CO2 levels, plants grown under elevated CO2 accumulated ca. 20% more biomass and 23% more leaf area. When measured at the CO2 concentration of growth, mature leaves of high-CO2-grown plants had higher light-saturated rates of photosynthesis (ca. 15%), lower stomatal conductance (71%), higher water-use
efficiency (225%) and higher dark respiration rates (100%). High-CO2-grown plants had lower carboxylation efficiencies (23%), measured under limiting CO2, and lower leaf protein contents (22%). Activities of a number of C3 and C4 cycle enzymes decreased on a leaf-area basis in the high-CO2-grown plants by 5–30%, with NADP-malate dehydrogenase exhibiting the greatest decrease. In contrast, activities of fructose
1,6-bisphosphatase and ADP-glucose pyrophosphorylase increased significantly under elevated CO2 condition (8% and 36%, respectively). These data show that the C4 plant maize may benefit from elevated CO2 through acclimation in the capacities of certain photosynthetic enzymes. The increased capacity to synthesize sucrose and
starch, and to utilize these end-products of photosynthesis to produce extra energy by respiration, may contribute to the
enhanced growth of maize under elevated CO2.
Received: 30 April 1999 / Accepted: 17 June 1999 相似文献
19.
Photosynthetic acclimation of rhododendrons to light intensity in relation to leaf water-related traits 总被引:1,自引:0,他引:1
Plant Ecology - Leaves under high light may suffer from risks caused by excessive light energy and dehydration. However, it remains unclear how leaf water-related traits affect the photosynthetic... 相似文献
20.
Contrasting acclimation abilities of two dominant boreal conifers to elevated CO2 and temperature
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Alexander G. Ivanov Vi Bui Marin Mema Norman P.A. Hüner Gunnar Öquist Danielle Way Vaughan Hurry 《Plant, cell & environment》2018,41(6):1331-1345
High latitude forests will experience large changes in temperature and CO2 concentrations this century. We evaluated the effects of future climate conditions on 2 dominant boreal tree species, Pinus sylvestris L. and Picea abies (L.) H. Karst, exposing seedlings to 3 seasons of ambient (430 ppm) or elevated CO2 (750 ppm) and ambient temperatures, a + 4 °C warming or a + 8 °C warming. Pinus sylvestris responded positively to warming: seedlings developed a larger canopy, maintained high net CO2 assimilation rates (Anet), and acclimated dark respiration (Rdark). In contrast, carbon fluxes in Picea abies were negatively impacted by warming: maximum rates of Anet decreased, electron transport was redirected to alternative electron acceptors, and thermal acclimation of Rdark was weak. Elevated CO2 tended to exacerbate these effects in warm‐grown Picea abies, and by the end of the experiment Picea abies from the +8 °C, high CO2 treatment produced fewer buds than they had 3 years earlier. Treatments had little effect on leaf and wood anatomy. Our results highlight that species within the same plant functional type may show opposite responses to warming and imply that Picea abies may be particularly vulnerable to warming due to low plasticity in photosynthetic and respiratory metabolism. 相似文献