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1.
Abstract Trace amounts of carbon monoxide were produced and subsequently consumed during the growth of Desulfovibrio vulgaris on organic electron donors. D. vulgaris also utilized carbon monoxide as the sole electron donor for growth and sulfate reduction. Growth of D. vulgaris on CO, H2 or organic electron donors was inhibited at ≥4.5% CO in the culture headspace. At lower CO concentrations, hydrogen was produced as a consequence of CO consumption and consumed when the CO partial pressure was decreased. The rate of CO consumption was ten-fold higher in D. vulgaris grown on either CO, lactate or pyruvate than when cells were grown on H2 as electron donor. The physiological function of CO metabolism and a CO-dependent hydrogen cycle in D. vulgaris is discussed. 相似文献
2.
Abstract Washed cells of Peptostreptococcus productus (strain Marburg), which were incubated in the presence of CO/CO2 /N2 (50%/ 17%/ 33%; 200 kPa) catalyzed the synthesis of acetate from carbon monoxide. The rate of acetate formation from CO was stimulated more than threefold by the addition of sodium (10 mM); potassium did not effect acetate synthesis. The degree of stimulation was dependent on the sodium concentration; the dependence followed simple Michaelis-Menten kinetics. The apparent K m for sodium was determined to be about 2 mmol/1. Sodium also stimulated acetate synthesis from H2 plus CO2 . In the absence of added sodium the formation of formate as an intermediate in methyl group synthesis was stimulated. It is suggested that the sodium dependent reaction(s) is one (or more) of the reactions involved in methyl group synthesis from CO2 . 相似文献
3.
Abstract Hydrogen consumption was measured in hot geothermal water from two ponds of the San Federigo solfatara, Tuscany, Italy, where emanation gases contained approx. 4% H2 . H2 consumption was completely inhibited by NaOH and partially by HgCl2 indicating microbial utilization. Aerobic and anaerobic H2 consumption activities coexisted in the same water with aerobic activity being higher in one pond and anaerobic activity in the other. The kinetics of H2 consumption were consistent with those of 'Knallgas', methanogenic or sulfidogenic bacteria. 相似文献
4.
Temporal change of gas metabolism by hydrogen-syntrophic methanogenic bacterial associations in anoxic paddy soil 总被引:4,自引:0,他引:4
Abstract Interspecies H2 transfer within methanogenic bacterial associations (MBA) accounted for 95–97% of the conversion of 14 CO2 to 14 CH4 in anoxic paddy soil. Only 3–5% of the 14 CH4 were produced from the turnover of dissolved H2 . The H2 -syntrophic MBA developed within 5 days after the paddy soil had been submerged and placed under anoxic atmosphere. Afterwards, both the contribution of MBA to H2 -dependent methanogenesis and the turnover of dissolved H2 did not change significantly for up to 7 months of incubation. However, while the rates of H2 -dependent methanogenesis stayed relatively constant, the rates of total methanogenesis decreased. The contribution of MBA to H2 -dependent methanogenesis was further enhanced to 99% when the temperature was shifted from 30°C to 17°C, or when the soil had been planted with rice. This enhancement was partially due to an increased utilization of dissolved H2 by chloroform-insensitive non-methanogenic bacteria, most probably homoacetogens, so that CH4 production was almost completely restricted to H2 -syntrophic MBA. The activity of MBA, as measured by the conversion of 14 CO2 to 14 CH4 , was stimulated by glucose, lactate, and ethanol to a similar or greater extent than by exogenous H2 . Propionate and acetate had no effect. 相似文献
5.
Jouko Silvola 《Ecography》1990,13(3):224-228
The photosynthesis of Spagnum fuscum (Schimp.) Klinggr. at different water contents and CO2 concentrations was measured in the laboratory. The optimal water content for photosynthesis near the current atmospheric CO2 concentration is 600–800% (percentage of dry weight). The decrease in photosynthesis is very steep towards lower water contents and less steep towards higher water contents. The optimal water content range moves higher and becomes wider with increasing CO2 concentration. At 3000 ppm there is no longer any decrease in photosynthesis with increasing water content. The water content of S. fuscum has a considerable effect on the response of photosynthesis to CO2 concentration. In a moss saturated with water, photosynthesis increases gradually until 8000 ppm CO2 , but this saturation concentration becomes lower with decreasing water content, being c. 1500 ppm at a water content of 700–800%. An increase in CO2 concentration over 300 ppm will raise photosynthesis very little in dry moss with a water content of only 300–400%. 相似文献
6.
Response of Mediterranean coralline algae to ocean acidification and elevated temperature 总被引:3,自引:0,他引:3
The effects of elevated partial pressure of CO2 ( p CO2 ) and temperature, alone and in combination, on survival, calcification and dissolution were investigated in the crustose coralline alga Lithophyllum cabiochae . Algae were maintained in aquaria during 1 year at near-ambient conditions of irradiance, at ambient or elevated temperature (+3 °C) and at ambient [ca. 400 parts per million (ppm)] or elevated p CO2 (ca. 700 ppm). Algal necroses appeared at the end of summer under elevated temperature first at 700 ppm (60% of the thallus surface) and then at 400 ppm (30%). The death of algae was observed only under elevated temperature and was two- to threefold higher under elevated p CO2 . During the first month of the experiment, net calcification was significantly reduced under elevated p CO2 . At the end of the summer period, net calcification decreased by 50% when both temperature and p CO2 were elevated while no effect was found under elevated temperature and elevated p CO2 alone. In autumn and winter, net calcification in healthy algae increased with increasing temperature, independently of the p CO2 level, while necroses and death in the algal population caused a net dissolution at elevated temperature and p CO2 . The dissolution of dead algal thalli was affected by elevated p CO2 , being two- to fourfold higher than under ambient p CO2 . These results suggest that net dissolution is likely to exceed net calcification in L. cabiochae by the end of this century. This could have major consequences in terms of biodiversity and biogeochemistry in coralligenous communities dominated by these algae. 相似文献
7.
Abstract: A continuous dual 13 CO2 and 15 NH4 15 NO3 labelling experiment was undertaken to determine the effects of ambient (350μmol mol-1 ) or elevated (700μmol mol-1 ) atmospheric CO2 concentrations on C and N uptake and allocation within 3-year-old beech ( Fagus sylvatica L.) during leafing. After six weeks of growth, total carbon uptake was increased by 63 % (calculated on total C content) under elevated CO2 but the carbon partitioning was not altered. 56 % of the new carbon was found in the leaves. On a dry weight basis was the content of structural biomass in leaves 10 % lower and the lignin content remained unaffected under elevated as compared to ambient [CO2 ]. Under ambient [CO2 ] 37 %, and under elevated [CO2 ] 51 %, of the lignin C of the leaves derived from new assimilates. For both treatments, internal N pools provided more than 90 % of the nitrogen used for leaf-growth and the partitioning of nitrogen was not altered under elevated [CO2 ]. The C/N ratio was unaffected by elevated [CO2 ] at the whole plant level, but the C/N ratio of the new C and N uptake was increased by 32 % under elevated [CO2 ]. 相似文献
8.
Abstract Clostridium thermoaceticum was cultivated heterotrophically under CO2 , carbon monoxide (CO), and H2 gas phases. Formate dehydrogenase (FDH) levels increased 4-fold in CO cultures; formyltetrahydrofolate synthetase (FTS) levels were not influenced by the cultivation gas phases tested. While CO dehydrogenase (CODH) was slightly stimulated in CO cultures, CO-dependent acetyl phosphate-synthesizing system (APSS) activity increased sharply in both CO and H2 cultures. Y glucose values increased, whereas doubling times and acetate to biomass ratios decreased significantly in CO cultures, suggesting that CO cultures were energetically dissimilar to non-CO cultures. This finding, together with the absence of CO-dependent ATP-independent synthesis of formyltetrahydrofolate (formyl-THF), supports the hypothesis that conservation of CO-derived energy involves electron transport phosphorylation. 相似文献
9.
Transformation of tetrachloroethylene to trichloroethylene by homoacetogenic bacteria 总被引:4,自引:0,他引:4
Abstract Eight homoacetogenic strains of the genera Acetobacterium, Clostridium and Sporomusa were tested for their ability to dechlorinate tetrachloroethylene (perchloroethene, PCE). Of the organisms tested only Sporomusa ovata was able to reductively dechlorinate PCE with methanol as an electron donor. Resting cells of S. ovata reductively dechlorinated PCE at a rate of 9.8 nmol h−1 (mg protein)−1 to trichloroethylene (TCE) as the sole product. The dechlorination activity depended on concomitant acetogenesis from methanol and CO2 . Cell-free extracts of S. ovata, Clostridium formicoaceticum, Acetobacterium woodii , and the methanogenic bacterium Methanolobus tindarius transformed PCE to TCE with Ti(III) or carbon monoxide as electron donors. Corrinoids were shown in S. ovata to be involved in the dechlorination reaction of PCE to TCE as evident from the reversible inhibition with propyl iodide. Rates of dechlorination followed a pseudo-first-order kinetic. 相似文献
10.
1. Four Lotus corniculatus genotypes differing in cyanoglycoside and condensed tannin concentrations were grown in either low (350 ppm) or high (700 ppm) atmospheric CO2 environments. Larval performance, consumption and conversion efficiency of Polyommatus icarus feeding on this plant material were measured.
2. Plants grown under elevated CO2 contained less cyanoglycosides, more condensed tannins and more starch than control plants. However, water concentration, nitrogen and protein as well as nitrogen concentration in relation to carbon concentration did not differ between CO2 treatments.
3. The four genotypes differed significantly in condensed tannins, cyanoglucoside, leaf water and leaf nitrogen but no genotype–CO2 interaction was detected, except for total phenolics and condensed tannins in which two plant genotypes showed stronger increases under elevated CO2 than the other two.
4. Larvae of P . icarus consumed more plant material and used and converted it more efficiently from plants grown at high atmospheric CO2 .
5. Larvae developed significantly faster and were significantly heavier when fed plant material grown under elevated CO2 . The observed difference in mass disappeared in the pupal and adult stages. However, lipid concentration of adults from the elevated CO2 treatment was marginally significantly higher than of controls.
6. It is concluded that the higher carbohydrate concentration of L . corniculatus plants grown at elevated CO2 renders leaves more suitable and better digestible to P . icarus . Furthermore, differences in allelochemicals might influence the palatability of L . corniculatus leaves for this specialist on Fabaceae. 相似文献
2. Plants grown under elevated CO
3. The four genotypes differed significantly in condensed tannins, cyanoglucoside, leaf water and leaf nitrogen but no genotype–CO
4. Larvae of P . icarus consumed more plant material and used and converted it more efficiently from plants grown at high atmospheric CO
5. Larvae developed significantly faster and were significantly heavier when fed plant material grown under elevated CO
6. It is concluded that the higher carbohydrate concentration of L . corniculatus plants grown at elevated CO
11.
Aims: To evaluate the effectiveness of organic acids and supercritical carbon dioxide (SC-CO2 ) treatments as well as their combined effect for the reduction of nonpathogenic Escherichia coli and three pathogenic bacteria in fresh pork.
Methods and Results: The different treatment conditions were as follows: (i) treatment with acetic (1%, 2% or 3%) or lactic acid (1%, 2% or 3%) only, (ii) treatment with SC-CO2 at 12 MPa and 35°C for 30 min only and (iii) treatment with 3% acetic or lactic acid followed by treatment with SC-CO2 . Within the same organic acid concentration, the lactic and acetic acid treatments had similar reductions. For the combined treatment of lactic acid and SC-CO2 , micro-organism levels were maximally reduced, ranging from 2·10 to 2·60 log CFU cm−2 ( E. coli , 2·58 log CFU cm−2 ; Listeria monocytogenes , 2·60 log CFU cm−2 ; Salmonella typhimurium , 2·33 log CFU cm−2 ; E. coli O157:H7, 2·10 log CFU cm−2 ).
Conclusions: The results of this study indicate that the combined treatments of SC-CO2 and organic acids were more effective at destroying foodborne pathogens than the treatments of SC-CO2 or organic acids alone.
Significance and Impact of the Study: The combination treatment of SC-CO2 and organic acids may be useful in the meat industry to help increase microbial safety. 相似文献
Methods and Results: The different treatment conditions were as follows: (i) treatment with acetic (1%, 2% or 3%) or lactic acid (1%, 2% or 3%) only, (ii) treatment with SC-CO
Conclusions: The results of this study indicate that the combined treatments of SC-CO
Significance and Impact of the Study: The combination treatment of SC-CO
12.
PCR amplification of the 3'' external transcribed and intergenic spacers of the ribosomal DNA repeat unit in three species of Saccharomyces 总被引:3,自引:0,他引:3
Abstract Desulfotomaculum thermobenzoicum TSB converted 4 mol pyruvate to 5 mol acetate in the absence of sulfate. The cells grown on pyruvate without sulfate showed both carbon monoxide dehydrogenase (CODH) and methylmalonyl-CoA: pyruvate transcarboxylase activities. However, considering the fermentation products, the acetogenesis from pyruvate might be conducted by CODH pathway rather than methylmalonyl-CoA pathway. Contrary to this finding, Desulfobulbus propionicus MUD fermented 3 mol pyruvate to 2 mol acetate and 1 mol propionate stoichiometrically via methylmalonyl-CoA pathway. Desulfovibrio vulgaris Marburg, which has neither the CODH pathway nor the methylmalonyl-CoA pathway, converted pyruvate to acetate, H2 and CO2 as the main products. These results indicate that the fermentation pattern of pyruvate depends on the metabolic characteristics of each sulfate-reducing bacterium. 相似文献
13.
Rice production in a changing climate: a meta-analysis of responses to elevated carbon dioxide and elevated ozone concentration 总被引:16,自引:0,他引:16
ELIZABETH A. AINSWORTH 《Global Change Biology》2008,14(7):1642-1650
Rice is arguably the most important food source on the planet and is consumed by over half of the world's population. Considerable increases in yield are required over this century to continue feeding the world's growing population. This meta-analysis synthesizes the research to date on rice responses to two elements of global change, rising atmospheric carbon dioxide concentration ([CO2 ]) and rising tropospheric ozone concentration ([O3 ]). On an average, elevated [CO2 ] (627 ppm) increased rice yields by 23%. Modest increases in grain mass and larger increases in panicle and grain number contributed to this response. The response of rice to elevated [CO2 ] varied with fumigation technique. The more closely the fumigation conditions mimicked field conditions, the smaller was the stimulation of yield by elevated [CO2 ]. Free air concentration enrichment (FACE) experiments showed only a 12% increase in rice yield. The rise in atmospheric [CO2 ] will be accompanied by increases in tropospheric O3 and temperature. When compared with rice grown in charcoal-filtered air, rice exposed to 62 ppb O3 showed a 14% decrease in yield. Many determinants of yield, including photosynthesis, biomass, leaf area index, grain number and grain mass, were reduced by elevated [O3 ]. While there have been too few studies of the interaction of CO2 and O3 for meta-analysis, the interaction of temperature and CO2 has been studied more widely. Elevated temperature treatments negated any enhancement in rice yield at elevated [CO2 ], which suggests that identifying high temperature tolerant germplasm will be key to realizing yield benefits in the future. 相似文献
14.
Sarita NEHARE Basweshwar S. GHODKI Gajanan K. LANDE Vrushali PAWADE Atul S. THAKARE 《Entomological Research》2010,40(1):18-25
Leaf-dip assay of Plutella xylostella against indoxacarb showed that the concentration that produced 50% mortality (LC50 ) of indoxacarb ranged from 20.1 to 11.9 ppm, with highest in Nasik and lowest levels in Coimbatore strains. In selection studies, the LC50 of indoxacarb was 18.5 ppm at generation 1 (G1), which increased to 31.3-fold (167.8 ppm) resistance after ten exposed generations (G10) as compared to unexposed. The LC50 of quinalphos was 74.4 ppm, which increased to 10.0-fold (631.5 ppm) resistance after G10. The LC50 of cypermethrin resistant strain resulted in an 11.5-fold increase in resistance after G10. In P. xylostella , heritability (h2 ) after ten generations of selection was estimated at 0.4. The number of generations required for tenfold increase in LC50 (1/R) were 6.7. The response to indoxacarb selection in P. xylostella was 0.2 and the selection differential was estimated as 0.4. The phenotypic standard deviation was 0.2. Reciprocal crosses between indoxacarb-resistant and susceptible strains showed that the inheritance of indoxacarb resistance was autosomal. The degree of heritability (DLC ) (0.4, 0.4) indicated incomplete recessive inheritance of indoxacarb resistance. 相似文献
15.
E. N. SPEELMAN M. M. L. VAN KEMPEN J. BARKE H. BRINKHUIS G. J. REICHART A. J. P. SMOLDERS J. G. M. ROELOFS F. SANGIORGI J. W. DE LEEUW A. F. LOTTER J. S. SINNINGHE DAMSTÉ 《Geobiology》2009,7(2):155-170
Enormous quantities of the free-floating freshwater fern Azolla grew and reproduced in situ in the Arctic Ocean during the middle Eocene, as was demonstrated by microscopic analysis of microlaminated sediments recovered from the Lomonosov Ridge during Integrated Ocean Drilling Program (IODP) Expedition 302. The timing of the Azolla phase (~48.5 Ma) coincides with the earliest signs of onset of the transition from a greenhouse towards the modern icehouse Earth. The sustained growth of Azolla , currently ranking among the fastest growing plants on Earth, in a major anoxic oceanic basin may have contributed to decreasing atmospheric p CO2 levels via burial of Azolla -derived organic matter. The consequences of these enormous Azolla blooms for regional and global nutrient and carbon cycles are still largely unknown. Cultivation experiments have been set up to investigate the influence of elevated p CO2 on Azolla growth, showing a marked increase in Azolla productivity under elevated (760 and 1910 ppm) p CO2 conditions. The combined results of organic carbon, sulphur, nitrogen content and 15 N and 13 C measurements of sediments from the Azolla interval illustrate the potential contribution of nitrogen fixation in a euxinic stratified Eocene Arctic. Flux calculations were used to quantitatively reconstruct the potential storage of carbon (0.9–3.5 1018 gC) in the Arctic during the Azolla interval. It is estimated that storing 0.9 1018 to 3.5 1018 g carbon would result in a 55 to 470 ppm drawdown of p CO2 under Eocene conditions, indicating that the Arctic Azolla blooms may have had a significant effect on global atmospheric p CO2 levels through enhanced burial of organic matter. 相似文献
16.
A relationship between carbon dioxide, photosynthetic efficiency and shade tolerance 总被引:2,自引:0,他引:2
Net photosynthesis and transpiration of seedlings from shade tolerant, moderately tolerant and intolerant tree species were measured in ambient carbon dioxide (CO2 ) concentrations ranging from 312 to 734 ppm. The species used, Fagus grandifolia Ehrh. (tolerant), Quercus alba L., Q. rubra L., Liriodendron tulipifera L. (moderately tolerant), Liquidambar styraciflua L. and Pinus taeda L. (intolerant), are found co-occurring in the mixed pine-hardwood forests of the Piedmont region of the southeastern United States. When seedlings were grown in shaded conditions, photosynthetic CO2 efficiency was significantly different in all species with the highest efficiency in the most shade tolerant species, Fagus grandifolia , and progressively lower efficiencies in moderately tolerant and intolerant species. Photosynthetic CO2 efficiency was defined as the rate of increase in net photosynthesis with increase in ambient CO2 concentration. When plants which had grown in a high light environment were tested, the moderately tolerant and intolerant deciduous species had the highest photosynthetic CO2 efficiencies but this capacity was reduced when these species grew in low light. The lowest CO2 efficiency and apparent quantum yield occurred in Pinus taeda in all cases. Water use efficiency was higher for all species in enriched CO2 environments but transpiration rate and leaf conductance were not affected by CO2 concentration. High photosynthetic CO2 efficiency may be advantageous for maintaining a positive carbon balance in the low light environment under a forest canopy. 相似文献
17.
Highbush blueberry plants ( Vaccinium corymbosum L. cv. Bluecrop) growing in containers were flooded in the laboratory for various durations to determine the effect of flooding on carbon assimilation, photosynthetic response to varying CO2 and O2 concentrations and apparent quantum yield as measured in an open flow gas analysis system. Hydraulic conductivity of the root was also measured using a pressure chamber. Root conductivity was lower and the effect of increasing CO2 levels on carbon assimilation less for flooded than unflooded plants after short-(i-2 days), intermediate-(10–14 days) and long-term (35–40 days) flooding. A reduction in O2 levels surrounding the leaves from 21 to 2% for unflooded plants increased carbon assimilation by 33% and carboxylation efficiency from 0.012 to 0.021 mol CO2 fixed (mol CO2 )−1 . Carboxylation efficiency of flooded plants, however, was unaffected by a decrease in percentage O2 , averaging 0.005 mol CO2 fixed (mol CO2 )−1 . Apparent quantum yield decreased from 2.2 × 10−1 mol of CO2 fixed (mol light)−1 for unflooded plants to 2.0 × 10−3 and 9.0 × 10−4 for intermediate- and long-term flooding durations, respectively. Shortterm flooding reduced carbon assimilation via a decrease in stomatal conductance, while longer flooding durations also decreased the carboxylation efficiency of the leaf. 相似文献
18.
DAVID N. KAROWE 《Global Change Biology》2007,13(10):2045-2051
When grown under elevated atmospheric carbon dioxide (CO2 ), leaf nitrogen content decreases less for legumes than for nonlegume C3 plants. Given that elevated CO2 adversely affects insect herbivores primarily through dilution of plant nitrogen, it is reasonable to expect that legume-feeding herbivores will be relatively buffered against CO2 -induced reduction in performance. However, despite their ecological and economic importance, very few studies have addressed the effects of elevated CO2 on legume-feeding herbivores. Unlike the responses of the vast majority of nonlegume C3 plants, when the legumes Trifolium pratense and Melilotus alba were grown under elevated (742 ppm) CO2 , leaf nitrogen and carbon contents and C : N ratios did not change. For Colias philodice larvae fed T. pratense , elevated CO2 had little or no effect on consumption, digestion, or conversion of whole food or nitrogen and, consequently, no effect on growth rate, instar duration, or pupal weight. For larvae fed M. alba , elevated CO2 had little or no effect on consumption of whole food or nitrogen, increased digestion but decreased conversion of both and, consequently, had no effect on growth rate, instar duration or pupal weight. These results suggest that, relative to herbivores of nonlegume C3 plants, legume-feeding herbivores will be less affected as atmospheric CO2 continues to rise. 相似文献
19.
Evidence for cytochrome P-450 and P-450-mediated benzo(a) pyrene hydroxylation in the white rot fungus Phanerochaete chrysosporium 总被引:2,自引:0,他引:2
Segula Masaphy Dan Levanon Yigal Henis K. Venkateswarlu Steven L. Kelly 《FEMS microbiology letters》1996,135(1):51-55
Abstract The presence of cytochrome P-450 and P-450-mediated benzo(a)pyrene hydroxylase activity in both microsomal and soluble fractions of the white rot fungus Phanerochaete chrysosporium was shown. The reduced carbon monoxide difference spectrum showed maxima at 448–450 and 452–454 nm for microsomal and cytosolic fractions, respectively. Both P-450 fractions produced a Type I substrate binding spectrum on addition of benzo(a)pyrene. Activity for benzo(a)pyrene hydroxylation was NADPH-dependent and inhibited by carbon monoxide. K m values for activity showed a difference between the cellular fractions with a K m of 89 μM for microsomal P-450 and 400 μM for cytosolic P-450. The V max values observed were 0.83 nmol min− (nmol microsomal P-450) −1 and 0.4 nmol min−1 (nmol cytosolic P-450)−1 . The results indicate that P-450-mediated benzo(a)pyrene hydroxylase activity could play a role in xenobiotic transformation by this fungus beside the known ligninolytic exocellular enzymes. 相似文献
20.
The glands of Tamarix aphylla: a system for salt recretion or for carbon concentration? 总被引:4,自引:0,他引:4
Yoav Waisel 《Physiologia plantarum》1991,83(3):506-510
During periods of high atmospheric humidity, twigs of Tamarix aphylla (L.) Karst. become covered by an alkaline solution. The pH of that solution fluctuates between 8.0 – 8.5 in the dark and 10.5 during the light hours. Such a solution, produced by the glands, constitutes an efficient trap for atmospheric CO2 . Upon the periodic drop in pH, much of the preabsorbed carbon may gradually be released from the solution. This enriches the immediate surroundings of the twigs with CO2 for prolonged periods of time. The expected concentrations of CO2 , at the boundary layer between the atmosphere and the surfaces of the twigs, are over 1 000 ppm. As net photosynthesis of T. aphylla reaches maximal rates only at CO2 concentrations of above 500 ppm, the plants may benefit from this extra source of carbon and may exploit it for maximal assimilation during the early morning hours. Thus, the "salt glands'of Tamarix , which are liable for the production of the alkaline recretum, may serve a triple purpose: (a) removal of excess salts out of the twigs, (b) provision of a cover of hygroscopic solutes that moistens the twigs and shortens the duration of transpiration, and (c) providing the plants with an environment enriched in CO2 . 相似文献