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1.
Y. A. Holthuijzen F. F. M. van Dissel-Emiliani J. G. Kuenen W. N. Konings 《Archives of microbiology》1987,147(3):285-290
Uptake of inorganic carbon (Ci) in the form of CO2 and/or HCO
3
-
was studied in the chemolithoautotroph Thiobacillus neapolitanus under energy (thiosulphate) or carbon (CO2) limitation. Uptake of C1 was found to be a metabolic energy dependent process since in the presence of uncouplers no uptake was observed. The accumulation level of Ci was higher in the CO2-limited cells (1000-to 1500-fold) in comparison to the thiosulphate-limited cells (500-to 800-fold). The process of uptake could be influenced by addition of ionophores. Inhibition of uptake and accumulation of Ci was found after addition of valinomycin which completely dissipated the electrical potential (). After addition of nigericin an increase in the uptake and accumulation of Ci was observed with a concomitant increase of the . These results suggest that the is the main driving force for uptake of Ci. However, uptake of Ci could never be found in the absence of electron transfer, or in cells in which the electron transfer chain was blocked by potassium cyanide. Electron transfer therefore appears to be an additional requirement for Ci uptake. Kinetic experiment on the uptake of inorganic carbon at different pH values suggest that CO2 is the carbon species taken up by T. neapolitanus.Abbreviations RuBisCO
ribulose-1,5-bisphosphate carboxylase
- DCCD
N,N1-dicyclohexylcarbodiimide
- CCCP
carbonyl cyanide m-chlorophenyl hydrazone
- FCCP
carbonyl cyanide p-trifluoro-methoxyphenyl hydrazone
- EDTA
sodium ethylene diamine tetraacetate 相似文献
2.
Leaf Gas Exchange and Water Relations of Grapevines Grown in Three Different Conditions 总被引:2,自引:1,他引:1
Moutinho-Pereira J.M. Correia C.M. Gonçalves B.M. Bacelar E.A. Torres-Pereira J.M. 《Photosynthetica》2004,42(1):81-86
Diurnal and seasonal changes in the leaf water potential (), stomatal conductance (g
s), net CO2 assimilation rate (P
N), transpiration rate (E), internal CO2 concentration (C
i), and intrinsic water use efficiency (P
N/g
s) were studied in grapevines (Vitis vinifera L. cv. Touriga Nacional) growing in low, moderate, and severe summer stress at Vila Real (VR), Pinhão (PI), and Almendra (AL) experimental sites, respectively. In VR and PI site the limitation to photosynthesis was caused more by stomatal limitations, while in AL mesophyll limitations were also responsible for the summer decline in P
N. 相似文献
3.
Thimmanaik S. Kumar S. Giridara Kumari G. Jyothsna Suryanarayana N. Sudhakar C. 《Photosynthetica》2002,40(2):233-236
Net photosynthetic rate (P
N), stomatal conductance (g
S), transpiration rate (E), intercellular CO2 concentration (C
i), leaf water potential (w), leaf area, chlorophyll (Chl) content, and the activities of photosynthetic carbon reduction cycle (PCR) enzymes in two mulberry (Morus alba L.) cultivars (drought tolerant Anantha and drought sensitive M-5) were studied during water stress and recovery. During water stress, P
N, g
S, and E declined whereas C
i increased. P
N, g
S, and E were less affected in Anantha than in M-5, which indicates tolerance nature of Anantha over M-5. Activities of ribulose-5-phosphate kinase, NAD- and NADP-glyceraldehyde-3-phosphate dehydrogenases, and 3-phosphoglycerate kinase decreased with increasing stress in both the cultivars. The enzyme activities less affected in tolerant (Anantha) than in sensitive cultivar (M-5) were restored after re-watering to almost initial values in both the cultivars. Re-watering of the plants led to an almost complete recovery of P
N, E, and g
S, indicating that a short-term stress brings about reversible effect in these two cultivars of mulberry. 相似文献
4.
The effect of leaf water potential () on net CO2 assimilation rate (A), stomatal conductance (g), transpiration (E) and water-use efficiency (WUE) was measured for three cultivars of cacao (Theobroma cacao L.) seedlings during three recurrent drought cycles. Net assimilation varied greatly at high water potentials, but as dropped below approximately -0.8 and -1.0 MPa, A was reduced to less than 1.5 mol CO2 m-2 s-1. The relation between g and A was highly significant and conformed to an asymptotic exponential model, with A approaching maximal values at stomatal conductances of 55–65 mmol H2O m-2 s-1. Net assimilation varied linearly (r=0.95) with transpiration, and the slope of the A-E relation (WUE) was approximately 3.0 mol CO2 mmol-1 H2O throughout the range of stomatal conductances observed. C
i was insensitive to water stress, even though both g and A were strongly affected. Under the experimental conditions used here, mesophyll photosynthesis did not appear to control g through changes in C
i. As stress intensified within each drying cycle, WUE of nonirrigated seedlings did not decline relative to that of controls even though CO2 and water vapor exchange rates underwent large displacements. The effect of seed source was highly significant for WUE, and the basis for observed differences among genotypes is discussed.Abbreviations ABA
Abscisic Acid 相似文献
5.
Liu H.Q. Jiang G.M. Zhang Q.D. Sun J.Z. Guo R.J. Gao L.M. Bai K.Z. Kuang T.Y. 《Photosynthetica》2002,40(2):237-242
Three winter wheat (Triticum aestivum L.) cultivars, representatives of those widely cultivated in Beijing over the past six decades, were grown in the same environmental conditions. Net photosynthetic rate (P
N) per unit leaf area and instantaneous water use efficiency (WUE) of flag leaves increased with elevated CO2 concentration. With an increase in CO2 concentration from 360 to 720 µmol mol–1, P
N and WUE of Jingdong 8 (released in 1990s and having the highest yield) increased by 173 and 81 %, while those of Nongda 139 (released in 1970s) increased by 88 and 66 %, and Yanda 1817 (released in 1945, with lowest yield) by 76 and 65 %. Jingdong 8 had the highest P
N and WUE values under high CO2 concentration, but Yanda 1817 showed the lowest P
N. Stomatal conductance (g
s) of Nongda 139 and Yanda 1817 declined with increasing CO2 concentration, but g
s of Jingdong 8 firstly went down and then up as the CO2 concentration further increased. Intercellular CO2 concentration (C
i) of Jingdong 8 and Nongda 139 increased when CO2 concentration elevated, while that of Yanda 139 increased at the first stage and then declined. Jingdong 8 had the lowest C
i of the three wheat cultivars, and Yanda 1817 had the highest C
i value under lower CO2 concentrations. However, Jingdong 8 had the highest P
N and lowest C
i at the highest CO2 concentration which indicates that its photosynthetic potential may be high. 相似文献
6.
A C3 monocot, Hordeum vulgare and C3 dicot, Vicia faba, were studied to evaluate the mechanism of inhibition of photosynthesis due to water stress. The net rate of CO2 fixation (A) and transpiration (E) were measured by gas exchange, while the true rate of O2 evolution (J
O2) was calculated from chlorophyll fluorescence analysis through the stress cycle (10 to 11 days). With the development of water stress, the decrease in A was more pronounced than the decrease in J
O2 resulting in an increased ratio of Photosystem II activity per CO2 fixed which is indicative of an increase in photorespiration due to a decrease in supply of CO2 to Rubisco. Analyses of changes in the J
O2
A ratios versus that of CO2 limited photosynthesis in well watered plants, and RuBP pool/RuBP binding sites on Rubisco and RuBP activity, indicate a decreased supply of CO2 to Rubisco under both mild and severe stress is primarily responsible for the decrease in CO2 fixation. In the early stages of stress, the decrease in C
i (intercellular CO2) due to stomatal closure can account for the decrease in photosynthesis. Under more severe stress, CO2 supply to Rubisco, calculated from analysis of electron flow and CO2 exchange, continued to decrease. However, C
i, calculated from analysis of transpiration and CO2 exchange, either remained constant or increased which may be due to either a decrease in mesophyll conductance or an overestimation of C
i by this method due to patchiness in conductance of CO2 to the intercellular space. When plants were rewatered after photosynthesis had dropped to 10–30% of the original rate, both species showed near full recovery within two to four days.Abbreviations
A-
net CO2 assimilation rate
-
A
*-
net CO2 assimilation rate plus dark respiration
- ATP-
adenosine triphosphate
- CABP-
carboxyarabinitol 1,5-bisphosphate
-
C
a-
ambient CO2 concentration
-
C
c-
CO2 concentration in the chloroplast
-
C
i-
intercellular CO2 concentration
-
E-
transpiration rate
-
g
m-
mesophyll conductance
-
g
s-
stomatal conductance
-
J
O2
true rate of O2 evolution
- LSD-
least significant difference
- PPFD-
photosynthetic photon flux density
- PS II-
Photosystem II
-
R
n-
dark respiration rate
- Rubisco-
ribulose 1,5-bisphosphate carboxylase/oxygenase
- RuBP-
ribulose 1,5-bisphosphate
-
RWC-
relative water content
- c-
rate of carboxylation
- o-
rate of oxygenation
- PSII-
quantum yield of Photosystem II
- -
CO2 compensation point in the absence of R
n
- -
water potential 相似文献
7.
The relationship between relative water content (R) and turgor potential (p) may be derived from pressure-volume (PV) curves and analyzed in various ways. Fifty PV curves were measured with the pressure chamber on leaves of durum wheat (Triticum durum L.). The plots of p versus R were highly variable and could not be adequately described by a single mathematical function. The area below the curve was therefore determined by means of an area meter. This procedure gave the integral of turgor from full saturation to the turgor-loss point. Responses to drought treatment could thus be quantified and partitioned into effects of osmotic adjustment and elastic adjustment. These two adjustment responses, which are probably of different metabolic origin, together improve turgor maintenance in durum wheat considerably.Abbreviations and symbols PV
pressure-volume
- R
relative water content
- Ti
turgor integral between full saturation and turgor-loss point
- p
turgor (pressure) potential 相似文献
8.
Effect of drought on ear and flag leaf photosynthesis of two wheat cultivars differing in drought resistance 总被引:3,自引:0,他引:3
We investigated net photosynthetic rate (PN) of ear and two uppermost (flag and penultimate) leaves of wheat cultivars Hongmangmai (drought resistant) and Haruhikari (drought sensitive) during post-anthesis under irrigated and non-irrigated field conditions. The PNof ear and flag leaf were significantly higher and less affected by drought in Hongmangmai than in Haruhikari. The rate of reduction in stomatal conductance (gs) was similar for the two cultivars, but intercellular CO2concentration (Ci) in the flag leaf of Hongmangmai was lower than that of Haruhikari in non-irrigated treatment. No differences were observed in leaf water potential (1) and osmotic adjustment of the flag leaf of the cultivars. These results imply that differences in photosynthetic inhibition on the flag leaf at low leaf 1between the cultivars were primarily due to non-stomatal effects. Hence the main physiological factor associated with yield stability of Hongmangmai under drought stress may be attributed to the capacity for chloroplast activity in the flag leaf, which apparently allows sustained PNof flag leaf during grain filling under drought stress. The higher PNof ear in Hongmangmai under drought could also be related to its drought resistance.This revised version was published online in March 2005 with corrections to the page numbers. 相似文献
9.
Interspecific Differences of Leaf Gas Exchange and Water Relations of Three Evergreen Mediterranean Shrub Species 总被引:1,自引:1,他引:0
Leaf gas exchange and plant water relations of three co-occurring evergreen Mediterranean shrubs species, Quercus ilex L. and Phillyrea latifolia L. (typical evergreen sclerophyllous shrubs) and Cistus incanus L. (a drought semi-deciduous shrub), were investigated in order to evaluate possible differences in their adaptive strategies, in particular with respect to drought stress. C. incanus showed the highest annual rate of net photosynthetic rate (P
N) and stomatal conductance (g
s) decreasing by 67 and 69 %, respectively, in summer. P. latifolia and Q. ilex showed lower annual maximum P
N and g
s, although P
N was less lowered in summer (40 and 37 %, respectively). P. latifolia reached the lowest midday leaf water potential (1) during the drought period (–3.54±0.36 MPa), 11 % lower than in C. incanus and 19 % lower than in Q. ilex. Leaf relative water content (RWC) showed the same trend as 1. C. incanus showed the lowest RWC values during the drought period (60 %) while they were never below 76 % in P. latifolia and Q. ilex; moreover C. incanus showed the lowest recovery of 1 at sunset. Hence the studied species are well adapted to the prevailing environment in Mediterranean climate areas, but they show different adaptive strategies that may be useful for their co-occurrence in the same habitat. However, Q. ilex and P. latifolia by their water use strategy seem to be less sensitive to drought stress than C. incanus. 相似文献
10.
The response of gas exchange and chlorophyll fluorescence along with changes in simulated rainfall were studied in water stressed plants Hedysarum fruticosum var. mongolicum (H.f.m.). Net photosynthetic rate (P
N), stomatal conductance (gs), leaf water potential (leaf), and apparent carboxylation efficiency (P
N/C
i) were significantly increased with the increase of rainfall. However, they did not change synchronously. The complete recovery of both P
N and P
N/C
i appeared 3 d after watering while g
s and leaf were recovered 1 d after treatment. Gas exchange characters increased sharply from 5 to 15 mm rainfall and then maintained steady state with increasing rainfall. During the initial phase of water recovery, photosystem 2 (PS2) activity was not affected and its complete recovery occurred also 3 d after rainfall. Hence the recovery of P
N was attributed to both opening of stomata and increase in carboxylation efficiency. Furthermore, PS2 activity was really impaired by water stress and could recover to the normal status when the water stress disappeared. 相似文献
11.
Eng-Chong Pua Elena Ragolsky Stephen F. Chandler Trevor A. Thorpe 《Plant Cell, Tissue and Organ Culture》1985,5(1):55-62
Callus of tobacco (Nicotiana tabacum L. cv. Wisconsin 38) was grown on callus-proliferating (CP) and shoot-forming (SF) media with elevated sodium sulfate (Na2SO4) concentrations either in the light or dark for more than one year. An increase in Na2SO4 concentration resulted in a decrease in callus growth index, an increase in percent dry weight of callus tissues grown on both media, and a decrease in both number of calli forming shoots and number of shoots per callus in SF medium. The CP callus grown in the light spontaneously began to form shoots after the 5th monthly transfer, and spontaneous root formation occured after the 16th transfer in the presence of 0.75 and 1.0% Na2SO4. Both water () and osmotic (s) potentials of the callus increased with increasing Na2SO4 concentration; and callus exhibited greater and s in the light than dark for both CP and SF media. 相似文献
12.
Relative water content (RWC), leaf water potential (w) and osmotic potential (s), contents of chlorophyll (Chl) a, Chl b, soluble sugars, and seed quality (gum content) were used to evaluate the role of phosphorus in alleviation of the deleterious effect of water deficit in clusterbean (Cyamopsis tetragonoloba L. Taub). Under water stress, w, s, and Chl and gum contents decreased and soluble sugar contents increased. Phosphorus application increased Chl and sugar contents in control plants and ameliorated negative effects of water stress. 相似文献
13.
Gas exchange, photochemical efficiency, and leaf water potential (l) of Salix matsudana (non-indigenous species), S. microstachya and S. gordejevii (indigenous species) were studied in Hunshandak Sandland, China. l of all the three species decreased from 06:00 to 12:00, and increased afterwards. S. matsudana showed higher values of l than others. Net photosynthetic rate (P
N) and stomatal conductance (g
s) of S. matsudana were the lowest among all, with the maximum P
N at 10:00 being 75% of that of S. gordejevii. Compared with the indigenous species, the non-indigenous S. matsudana had also lower transpiration rate (E) and water use efficiency (WUE). The values of Fv/Fm in all the species were lower from 06:00 to 14:00 than those after 14:00, indicating an obvious depression in photochemical efficiency of photosystem 2 in both non-indigenous and native species. However, it was much more depressed in S. matsudana, the non-indigenous tree. P
N was positively correlated to g
s and negatively related to l. The relationship between g
s and vapour pressure difference (VPD) was exponential, while negative linear correlation was found between g
s and l. 相似文献
14.
Diurnal patterns of leaf water potential (W), canopy net photosynthetic rate (P
N), evapotranspiration rate (E), canopy temperature (Tc), and water use efficiency (WUE) of clusterbean [Cyamopsis tetragonoloba (L.) Taub., cv. Desi] were studied at six phenological stages of plant development under field conditions at CCS Haryana Agricultural University, Hisar. The highest P
N, E, and WUE were observed at pod initiation stage (61 DAS). Daily maxima of P
N were usually between 11:00 to 14:00 h while those of E and WUE between 12:30 and 16:00 h. P
N was mainly dependent on photosynthetically active radiation and E on air temperature (Ta) but the relationships varied at different growth stages. WUE declined with the increase in T
a. At mid-day, W was highest during pod initiation. 相似文献
15.
The role of three-turgor-related cellular parameters, the osmotic potential (
s), the wall yield stress (Y) and the apparent hydraulic conductivity (L'p), in the initiation of ligh-induced expansion of bean (Phaseolus vulgaris L.) leaves has been determined. Although light causes an increase in the total solute content of leaf cells, the water uptake accompanying growth results in a slight increase in
s. Y is about 4 bar; and is unaffected by light. L'p, as calculated from growth rates and isopiestic measurements of leaf water potential, is only slightly greater in rapidly-growing leaves. The turgor pressure of growing cells is lower than that of the controls by about 35%. We conclude that light does not induce cell enlargement in the leaf by altering any of the above parameters, but does so primarily by increasing wall extensibility.Abbreviations and symbols RL
red light
- WL
white light
- L'p
apparent hydraulic conductivity
- OC
osmotic concentration
- Y
wall yield stress
-
s
osmotic potential 相似文献
16.
Effects of water-stress treatment of Zea mays L. plants on protoplast volume and photosynthesis in leaf slices exposed to solutions of different osmotic potential (
s) were studied. Decreased photosynthetic capacity in the leaf slices at low tissue
w was associated with dehydration-induced protoplast-volume reduction. Leaf slices from plants exposed to in-situ water deficits exhibited greater photosynthetic capacity and relative protoplast volume at low water potential (
w) invitro than tissue from control plants.In-situ water stress induced osmotic adjustment of the leaf tissue as determined by pressure/volume analysis. It is concluded that plant acclimation to low leaf
w may involve a reduced degree of cell shrinkage at a given
w. This acclimation would allow for the maintenance of relatively higher photosynthetic capacity at low water protentials.Symbols
s
Osmotic potential
-
w
water potential
New Jersey Agricultural Experiment Station Publication No. 12149-6-87 相似文献
17.
Osmotic adjustment and the inhibition of leaf,root, stem and silk growth at low water potentials in maize 总被引:21,自引:0,他引:21
The expansion growth of plant organs is inhibited at low water potentials (
w), but the inhibition has not been compared in different organs of the same plant. Therefore, we determined elongation rates of the roots, stems, leaves, and styles (silks) of maize (Zea mays L.) as soil water was depleted. The
w was measured in the region of cell expansion of each organ. The complicating effects of transpiration were avoided by making measurements at the end of the dark period when the air had been saturated with water vapor for 10 h and transpiration was less than 1% of the rate in the light. Growth was inhibited as the
w in the region of cell expansion decreased in each organ. The
w required to stop growth was-0.50,-0.75, and-1.00 MPa, in this order, in the stem, silks, and leaves. However, the roots grew at these
w and ceased only when
w was lower than-1.4 MPa. The osmotic potential decreased in each region of cell expansion and, in leaves, roots and stems, the decrease was sufficient to maintain turgor fully. In the silks, the decrease was less and turgor fell. In the mature tissue, the
w of the stem, leaves and roots was similar to that of the soil when adequate water was supplied. This indicated that an equilibrium existed between these tissues, the vascular system, and the soil. At the same time, the
w was lower in the expanding regions than in the mature tissues, indicating that there was a
w disequilibrium between the growing tissue and the vascular system. The disequilibrium was interpreted as a
w gradient for supplying water to the enlarging cells. When water was withheld, this gradient disappeared in the leaf because
w decreased more in the xylem than in the soil, indicating that a high flow resistance had developed in the xylem. In the roots, the gradient did not decrease because vascular
w changed about the same amount as the soil
w. Therefore, the gradient in
w favored water uptake by roots but not leaves at low
w. The data show that expansion growth responds to low
w differently in different growing regions of the plant. Because growth depends on the maintenance of turgor for extending the cell walls and the presence of
w gradients for supplying water to the expanding cells, several factors could have been responsible for these differences. The decrease of turgor in the silks and the loss of the
w gradient in the leaves probably contributed to the high sensitivity of these organs. In the leaves, the gradient loss was so complete that it would have prevented growth regardless of other changes. In the roots, the maintenance of turgor and
w gradients probably allowed growth to continue. This difference in turgor and gradient maintenance could contribute to the increase in root/shoot ratios generally observed in water-limited conditions.Symbols
s
osmotic potential
-
w
water potential 相似文献
18.
The rate of photosynthesis (P
N) in leaves and pods as well as carbon isotope content in leaves, pod walls, and seeds was measured in well-watered (WW) and water-stressed (WS) chickpea plants. The P
N, on an area basis, was negligible in pods compared to leaves and was reduced by water stress (by 26%) only in leaves. WS pod walls and seeds discriminated less against 13CO2 than did the controls. This response was not observed for leaves as is usually the case. Pod walls and seeds discriminated less against 13CO2 than did leaves in both WW and WS plants. Measurement of carbon isotope composition in pods may be a more sensitive tool for assessing the impact of water stress on long-term assimilation than is the instantaneous measurement of gas exchange rates. 相似文献
19.
K. Palanisamy 《Photosynthetica》1999,36(4):635-638
Response of net photosynthetic rate (P
N), stomatal conductance (g
s), intercellular CO2 concentration (c
i), and photosynthetic efficiency (Fv/Fm) of photosystem 2 (PS2) was assessed in Eucalyptus cladocalyx grown for long duration at 800 (C800) or 380 (C380) μmol mol-1 CO2 concentration under sufficient water supply or under water stress. The well-watered plants at C800 showed a 2.2 fold enhancement of P
N without any change in g
s. Under both C800 and C380, water stress decreased P
N and g
s significantly without any substantial reduction of c
i, suggesting that both stomatal and non-stomatal factors regulated P
N. However, the photosynthetic efficiency of PS2 was not altered.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
20.
Seasonal water potential changes and proline accumulation in mediterranean shrubland species 总被引:1,自引:0,他引:1
We studied the water relations of 6 shrub and 3 tree species typical of the mediterranean climate region of central Spain to identify differential responses to water stress between and within species, and to determine if free proline concentration in leaves could be used as a water stress indicator. Predawn and midday water potentials (w) on a seasonal basis, relative water content (RWC), leaf mass per area, foliar nitrogen and free proline concentrations were measured. The lowest water potentials were observed at the end of the summer, with recovery to higher water potentials in the fall and winter seasons. Species differed regarding the annual w fluctuation. Thymus zygis, Halimium viscosum, Genista hirsuta and Juniperus oxycedrus exhibited the most negative midday and predawn w (both less than -6 MPa) with a large magnitude of response to changing conditions in soil moisture of the upper horizon of the soil. Lavandula pedunculata and Cistus ladanifer showed a moderate response. Quercus rotundifolia, Quercus faginea and Retama sphaerocarpa showed a modest response. The w of different size individuals of Quercus rotundifolia and Cistus ladanifer were compared. The annual w fluctuation was greater in small individuals as compared to large individuals. In every species, there was an increase in proline concentration of bulk leaf tissues when predawn w dropped below -5 MPa. Small plants of Cistus ladanifer reached lower water potentials and also higher concentration of proline than bigger plants. Proline could possibly be used as a drought stress indicator in every species except Q. rotundifolia. It is suggested that in addition to water stress avoidance due to deep root systems, some mechanisms of water stress tolerance may operate among shrub and tree species of central Spain. 相似文献