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1.
Treatment of jack pine (Pinus banksiana Lamb.) seedlings with gaseous SO2 resulted in a shift between the reducing and non-reducing sugars. Increasing concentrations of gaseous SO2 caused an increase in reducing sugars and a decline in the non-reducing sugars, suggesting a conversion from the latter to the former at high SO2 concentrations. The total amino acid content of the intact tissues also increased with increasing concentrations of gaseous SO2. Gas-liquid chromatographic analyses of the amino acids indicated that SO2 (1. 34 mg · m-3 for 96 h) resulted in an increase in the content of alanine, valine, glycine, isoleucine, leucine, threonine, aspartic acid tyrosine, lysine, and arginine, and a decrease in the content of serine and glutamic acid. The enzymatic and other implications of such changes are discussed. 相似文献
2.
Equilibrium and dynamic investigations of organic acids adsorption onto ion-exchange resins 总被引:2,自引:0,他引:2
The aim of the study was to determine properties of selected ion-exchange resins for citric and lactic acids recovery, to define sorption isotherms for these acids at different temperatures (in the range of 20–60°C) and to determine diffusion coefficients inside sorbent particles. A mathematical model of the ion-exchange process in the chromatographic column and its experimental verification is also presented. During investigations 18 types of ion-exchange resins were tested. It was found that weakly basic resins were more suitable for the recovery process than strongly basic ones. The best resin for the separation of citric acid was Amberlite IRA-67 and for lactic acid Amberlite IRA-92. As a result of transient-state sorption experiments diffusion coefficients of the citric acid inside the sorbent particle at different temperatures were obtained. It was found that Dp increased with the temperature by two times in the range of 20–60°C, and its value at 60°C was 7.2×10–10 m2/s. The proposed mathematical model was applied to identify bed operation parameters in the column for the needs of the simulated moving bed chromatography method.List of symbols b Equilibrium constant in Langmuir equation, [dm3/g] - c Acid concentration in the liquid phase inside the particle pores, [g/dm3] - C Acid concentration in the liquid, [g/dm3] - DL Axial dispersion coefficient, [m2/s] - Dp Intraparticle diffusion coefficient, [m2/s] - kf Liquid film mass transfer coefficient, [m/s] - L Ion-exchanger bed height, [m] - q Acid concentration in the adsorbent phase, [g/dm3] - Rp Particle radius, [m] - U Volumetric flow rate of the feeding solution, [dm3/s] - V Volume of the solution, [dm3] - W Weight of the wet resin particles, [g] - The ion-exchanger bed porosity, [-] - p Particle porosity, [-] - Linear liquid velocity, [m/s] - Apparent density of the wet resin, [g/dm3] 相似文献
3.
Background
Laser microdissection (LMD) has been established for isolation of individual tissue types from herbaceous plants. However, there are few reports of cell- and tissue-specific analysis in woody perennials. While microdissected tissues are commonly analyzed for gene expression, reports of protein, enzyme activity and metabolite analysis are limited due in part to an inability to amplify these molecules. Conifer stem tissues are organized in regular patterns with xylem, phloem and cortex development controlled by the activity of the cambial zone (CZ). Defense responses of conifer stems against insects and pathogens involve increased accumulation of terpenoids in cortical resin ducts (CRDs) and de novo formation of traumatic resin ducts from CZ initials. These tissues are difficult to isolate for tissue-specific molecular and biochemical characterization and are thus good targets for application of LMD. 相似文献4.
1-Aminocyclopropane-1-carboxylic acid (ACC) is known to be converted to ethylene and conjugated into N-malonyl-ACC in plant tissues. When -amino[1-14C]isobutyric acid (AIB), a structural analog of ACC, was administered to mungbean (Vigna radiata L.) hypocotyl segments, it was metabolized to 14CO2 and conjugated to N-malonyl-AIB (MAIB). -Aminoisobutyric acid inhibited the conversion of ACC to ethylene and also inhibited, to a lesser extent, N-malonylation of ACC and d-amino acids. Although the malonylation of AIB was strongly inhibited by ACC as well as by d-amino acids, the metabolism of AIB to CO2 was inhibited only by ACC but not by d-amino acids. Inhibitors of ACC conversion to ethylene such as anaerobiosis, 2,4-dinitrophenol and Co2+, similarly inhibited the conversion of AIB to CO2. These results indicate that the malonyalation of AIB to MAIB is intimately related to the malonylation of ACC and d-amino acids, whereas oxidative decarboxylation of AIB is related to the oxidative degradation of ACC to ethylene.Abbreviations ACC
1-aminocyclopropane-1-carboxylic acid
- AIB
-aminoisobutyric acid
- MACC
1-(malonylamino)-cyclopropane-1-carboxylic acid
- MAIB
-(malonylamino)-isobutyric acid
- Mes
2-(N-morpholino)ethanesulfonic acid 相似文献
5.
Mapping QTL controlling fatty acid composition in a doubled haploid rapeseed population segregating for oil content 总被引:2,自引:0,他引:2
Jianyi Zhao Zoran Dimov Heiko C. Becker Wolfgang Ecke Christian Möllers 《Molecular breeding : new strategies in plant improvement》2008,21(1):115-125
Increasing oil content and improving the fatty acid composition in the seed oil are important breeding goals for rapeseed
(Brassica napus L.). The objective of the study was to investigate a possible relationship between fatty acid composition and oil content
in an oilseed rape doubled haploid (DH) population. The DH population was derived from a cross between the German cultivar
Sollux and the Chinese cultivar Gaoyou, both having a high erucic acid and a very high oil content. In total, 282 DH lines
were evaluated in replicated field experiments in four environments, two each in Germany and in China. Fatty acid composition
of the seed oil was analyzed by gas liquid chromatography and oil content was determined by NIRS. Quantitative trait loci
(QTL) for fatty acid contents were mapped and their additive main effects were determined by a mixed model approach using
the program QTLMapper. For all fatty acids large and highly significant genetic variations among the genotypes were observed.
High heritabilities were determined for oil content and for all fatty acids (h
2 = 0.82 to 0.94), except for stearic acid content (h
2= 0.38). Significant correlations were found between the contents of all individual fatty acids and oil content. Closest genetic
correlations were found between oil content and the sum of polyunsaturated fatty acids (18:2 + 18:3;
r
G = −0.46), the sum of monounsaturated fatty acids (18:1 + 20:1 + 22:1; r
G = 0.46) and palmitic acid (16:0; r
G = −0.34), respectively. Between one and eight QTL for the contents of the different fatty acids were detected. Together, their
additive main effects explained between 28% and 65% of the genetic variance for the individual fatty acids. Ten QTL for fatty
acid contents mapped within a distance of 0 to 10 cM to QTL for oil content, which were previously identified in this DH population.
QTL mapped within this distance to each other are likely to be identical. The results indicate a close interrelationship between
fatty acid composition and oil content, which should be considered when breeding for increased oil content or improved oil
composition in rapeseed. 相似文献
6.
T. Kramer T. Michelberger H. Gürtler G. Gäbel 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1996,166(4):262-269
Investigations on the absorption of shortchain fatty acids across ruminal epithelium of sheep were performed both in vitro (Ussing chamber technique, using propionic acid representatively for shortchain fatty acids) and in vivo (washed, isolated reticulorumen). A pH-induced, nearly tenfold increase in the concentration of undissociated propionate led to an only twofold increase in mucosal-to-serosal flux of propionate (in vitro). Neither amiloride (1 mmol·l-1, in vitro) nor theophylline (10 mmol·l-1, in vivo), inhibitors of the ruminal Na+/H+ exchanger, exerted any significant influence on propionate fluxes or short-chain fatty acids absorption, respectively. Total replacement of luminal Na+ (by choline) did not alter short-chain fatty acids absorption (in vivo). Mucosal 4,4-diisothiocyanatostilbene-2,2-disulfonic acid (0.1 mmol·l-1) or mucosal nitrate (40 mmol·l-1) markedly reduced propionate net flux (in vitro). Increasing mucosal Cl- concentration brought about a significant drop in mucosal-to-serosal flux of propionate (in vitro) and in short-chain fatty acids net absorption (in vivo), respectively. The results obtained suggest that short-chain fatty acids are absorbed both as anions and as undissociated acids across ruminal epithelium of sheep. It is concluded that short-chain fatty acids anions either compete with Cl- for binding sites at a common anion-exchange mechanism or that they are absorbed by an short-chain fatty acids anion/HCO
3
-
exchanger indirectly coupled to a Cl-/HCO
3
-
exchanger via intracellular bicarbonate.Abbreviations
DIDS
4,4-diisothiocyanatostilbene-2,2-disulfonic acid
-
DMSO
dimethylsulfoxide
-
G
t
tissue conductance
-
HSCFA
protonated
- SCFA
i.e. undissociated form
-
J
ms
mucosal-to-serosal flux
-
J
sm
serosal-to-mucosal flux
-
J
net
net flux
-
I
sc
short-circuit current
-
MOPS
(3-[N-morpholino]propanesulfonic acid)
-
mu
mucosal
-
Prop
Propionate
-
SCFA
- SCFA
anions, i.e. dissociated form
-
SCFA
short-chain fatty acids
-
SEM
standard error of mean 相似文献
7.
Effects of excitatory neurotransmitter amino acids on swelling of rat brain cortical slices. 总被引:2,自引:0,他引:2
Abstract— With the single rat brain cortical slice serving as an in vitro bio-assay system, the effects of neurotransmitter amino acids (1 mm ) on brain swelling, water, sodium and potassium content, inulin space, and lactate production were studied. The putative dicarboxylic amino acid neurotransmitters, l -glutamic acid and l -aspartic acids, greatly increased intracellular brain swelling with increased intracellular Na+, water content and lactate production, and decreased inulin space and intracellular K+. Equimolar GABA, taurine, glycine, the putative inhibitory neurotransmitter amino acids, and equimolar α-amino-isobutyric acid had no effect. Brain swelling and intracellular Na+/K+ ratios were greatly increased by l -glutamate and l -aspartate at a concentration of 10 mm . However, l -aspartate at these concentrations greatly depleted the K+ content and lactate production as compared to l -glutamate. Further studies indicated that only the structural analogs and isomers of the dicarboxylic amino acids possessing two acidic groups and an α-amino group had a similar effect on the induction of brain swelling. Among the analogs of glutamic acid, dl -homocysteic acid and kainic acid had a greater effect on brain swelling, as observed from the total adenosine 5′-triphosphate (ATP) levels and the time-course and dose-response. A biphasic response in lactate production was induced by dl -homocysteic acid and kainic acid, suggesting that these analogs had a neurotoxic effect on cellular metabolism at higher concentrations. 相似文献
8.
Summary We have studied how differences in needle resin acid concentrations between two clones of Scots pine influenced larval survival, larval developmental time, and cocoon weight in Neodiprion sertifer. Larvae were reared under controlled conditions in the laboratory on needles showing a three-fold difference, in resin acid concentration. Larval developmental time was significantly longer for larvae fed needles high in resin acids. No significant differences were found in cocoon weight. Larvae fed needles high in resin acids suffered significantly higher mortality, most of which occurred, in the first two instars. Data on relative growth rate for last-instar larvae, based on a traditional growth efficiency experiment, did not show any negative effects of resin acids, indicating that a possible induction takes place during early instars. Observations on the feeding behaviour of last-instar larvae, the high consumption of bark tissue (with high concentrations of resin acids) by larvae fed needles low in resin acids and preference for needle tissues high in resin acids, indicate that these larvae might actively search for tissues rich in resin acids. We conclude that the physiology and behaviour of N. sertifer has been shaped, in part, by the conflict between the negative effects of resin acids, primarily in early instars (longer developmental time with a corresponding increase in exposure to natural enemies and an increase in direct mortality), and the positive effect of resin acids in later instars (a need for resin acids for use in its own predator defence secretion). 相似文献
9.
G. Corduan 《Planta》1970,91(4):291-301
Summary It is possible to obtain autotrophic callus cultures by inhibiting cell respiration. During a first passage of four weeks the cultures synthesized chlorophyll on an agar-medium with a minimum of organic substances such as sugar, amino acids and vitamins. In the second passage these cultures were kept on the same medium but were aerated with a mixture of 99% N2 and 1% CO2. In the third and last passage the medium contained only mineral substances and the same mixture of N2 and CO2 was used for aeration. This pure mineral medium was supplemented with the Hoagland's solution.These autotrophic callus cultures were grown for about two years under these conditions and showed a growth quotient of ten.Three different groups of tissues were taken for the 14CO2-fixation. The first group was grown for four weeks on a heterotrophic medium and aerated with O2. This is the socalled respirating group. The second and third group were both aerated with the mixture of N2/CO2 but they were grown on different mediums. One of these groups was grown on a heterotrophic medium for four weeks: these are heterotrophic photosynthesizing tissues. The third group was grown on a pure mineral medium, and these are the autotrophic photosynthesizing callus tissues.Respirating tissues are different from photosynthesizing cultures in respect to the quantity of light-induced CO2-fixation.The thin-layer chromatograms reveal the difference between heterotrophic and autotrophic tissues. In the light dependent 14CO2-incorporation the difference is in the amounts of the labelled amino acids glycine and serine. In the dark dependent incorporation the difference is found in the amount of the labelled amino acid aspartic acid. The more autotrophic these tissues are, the higher the level of the CO2-fixation in these amino acids is.
Mit Hilfe der Deutschen Forschungsgemeinschaft. 相似文献
Mit Hilfe der Deutschen Forschungsgemeinschaft. 相似文献
10.
To gain insight into the metabolic design of the amino acid carrier systems in fish, we injected a bolus of 15N amino acids into the dorsal aorta in mature rainbow trout (Oncorhynchus mykiss). The plasma kinetic parameters including concentration, pool size, rate of disappearance (R
d), half-life and turnover rate were determined for 15 amino acids. When corrected for metabolic rate, the R
d values obtained for trout for most amino acids were largely comparable to human values, with the exception of glutamine (which
was lower) and threonine (which was higher). R
d values ranged from 0.9 μmol 100 g−1 h−1 (lysine) to 22.1 μmol 100 g−1 h−1 (threonine) with most values falling between 2 and 6 μmol 100 g−1 h−1. There was a significant correlation between R
d and the molar proportion of amino acids in rainbow trout whole body protein hydrolysate. Other kinetic parameters did not
correlate significantly with whole body amino acid composition. This indicates that an important design feature of the plasma-free
amino acids system involves proportional delivery of amino acids to tissues for protein synthesis. 相似文献
11.
该文以14个扦插培育的甜叶菊品种叶为材料,从8种不同型号的树脂中筛选出一种合适的大孔吸附树脂对甜叶菊叶中绿原酸类成分进行纯化前处理,采用HPLC法对不同甜叶菊品种叶中所含绿原酸类成分进行比较分析。结果表明:(1)在8种不同型号的树脂中,XAD-16对甜叶菊叶中绿原酸类成分吸附-解析性能最佳。(2)经优化,上样液浓度1.20 mg·mL-1、样品溶液pH 3、解析液乙醇体积分数70%时XAD-16树脂对甜叶菊叶中绿原酸类成分具有较好的纯化效果。(3) HPLC检测分析表明,在14个品种中共检测出新绿原酸、绿原酸、隐绿原酸、异绿原酸B、异绿原酸A、异绿原酸C六种绿原酸类成分,其中主要成分均为异绿原酸A、绿原酸、异绿原酸C,而在品种3、5、13、14中没有检测出异绿原酸B。(4) 14个品种中6个绿原酸类成分的含量分别为异绿原酸A 20.5554.3 mg·g-1、绿原酸17.9632.93 mg·g-1、异绿原酸C 4.151<... 相似文献
12.
Leif Christensen Richard Fitzpatrick Brian Gildea Kenneth H. Petersen Henrik F. Hansen Troels Koch Michael Egholm Ole Buchardt Peter E. Nielsen James Coull Rolf H. Berg 《Journal of peptide science》1995,1(3):175-183
Peptide nucleic acids (PNA) were synthesized by a modified Merrifield method using several improvements. Activation by O-(benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate in combination with in situ neutralization of the resin allowed efficient coupling of all four Boc-protected PNA monomers within 30 min. HPLC analysis of the crude product obtained from a fully automated synthesis of the model PNA oligomer H-CGGACTAAGTCCATTGC-Gly-NH2, indicated an average yield per synthetic cycle of 97.1%. N1-benzyloxycarbonyl-N63-methylimidazole triflate substantially outperformed acetic anhydride as a capping reagent. The resin-bound PNAs were successfully cleaved by the ‘low–high’ trifluoromethanesulphonic acid procedure. 相似文献
13.
Optimization of growth and fatty acid composition of a unicellular marine picoplankton,Nannochloropsis sp., with enriched carbon sources 总被引:5,自引:0,他引:5
A unicellular marine picoplankton, Nannochloropsis sp., was grown under CO2-enriched photoautotrophic or/and acetate-added mixotrophic conditions. Photoautotrophic conditions with enriched CO2 of 2800 l CO2 l–1 and aeration gave the highest biomass yield (634 mg dry wt l–1), the highest total lipid content (9% of dry wt), total fatty acids (64 mg g–1 dry wt), polyunsaturated fatty acids (35% total fatty acids) and eicosapentaenoic acid (EPA, 20:53) (16 mg g–1 dry wt or 25% of total fatty acids). Mixotrophic cultures gave a greater protein content but less carbohydrates. Adding sodium acetate (2 mM) decreased the amounts of the total fatty acids and EPA. Elevation of CO2 in photoautotrophic culture thus enhances growth and raises the production of EPA in Nannochloropsis sp. 相似文献
14.
John Gutknecht 《The Journal of membrane biology》1988,106(1):83-93
Summary Mechanisms of proton conductance (G
H) were investigated in phospholipid bilayer membranes containing long-chain fatty acids (lauric, myristic, palmitic, oleic or phytanic). Membranes were formed from diphytanoyl phosphatidylcholine in decane plus chlorodecane (usually 30% vol/vol). Fatty acids were added either to the aqueous phase or to the membrane-forming solution. Proton conductance was calculated from the steadystate total conductance and the H+ diffusion potential produced by a transmembrane pH gradient. Fatty acids causedG
H to increase in proportion to the first power of the fatty acid concentration. TheG
H induced by fatty acids was inhibited by phloretin, low pH and serum albumin.G
H was increased by chlorodecane, and the voltage dependence ofG
H was superlinear. The results suggest that fatty acids act as simple (A– type) proton carriers. The membrane: water partition coefficient (K
p
) and adsorption coefficient () were estimated by finding the membrane and aqueous fatty acid concentrations which gave identical values ofG
H. For palmitic and oleic acidsK
p
was about 105 and was about 10–2 cm. The A– translocation or flip-flop rate (k
a
) was estimated from the value ofG
H and the fatty acid concentration in the membrane, assuming that A– translocation was the rate limiting step in H+ transport. Thek
A
's were about 10–4 sec–1, slower than classical weak-acid uncouplers by a factor of 105. Although long-chain fatty acids are relatively inefficient H+ carriers, they may cause significant biological H+ conductance when present in the membrane at high concentrations, e.g., in ischemia, hypoxia, hormonally induced lipolysis, or certain hereditary disorders, e.g., Refsum's (phytanic acid storage) disease. 相似文献
15.
Productivity in boreal ecosystems is primarily limited by available soil nitrogen (N), and there is substantial interest in understanding whether deposition of anthropogenically derived reactive nitrogen (Nr) results in greater N availability to woody vegetation, which could result in greater carbon (C) sequestration. One factor that may limit the acquisition of Nr by woody plants is the presence of bryophytes, which are a significant C and N pool, and a location where associative cyanobacterial N‐fixation occurs. Using a replicated stand‐scale N‐addition experiment (five levels: 0, 3, 6, 12, and 50 kg N ha?1 yr?1; n=6) in the boreal zone of northern Sweden, we tested the hypothesis that sequestration of Nr into bryophyte tissues, and downregulation of N‐fixation would attenuate Nr inputs, and thereby limit anthropogenic Nr acquisition by woody plants. Our data showed that N‐fixation per unit moss mass and per unit area sharply decreased with increasing N addition. Additionally, the tissue N concentrations of Pleuorzium schreberi increased and its biomass decreased with increasing N addition. This response to increasing N addition caused the P. schreberi N pool to be stable at all but the highest N addition rate, where it significantly decreased. The combined effects of changed N‐fixation and P. schreberi biomass N accounted for 56.7% of cumulative Nr additions at the lowest Nr addition rate, but only a minor fraction for all other treatments. This ‘bryophyte effect’ can in part explain why soil inorganic N availability and acquisition by woody plants (indicated by their δ15N signatures) remained unchanged up to N addition rates of 12 kg ha?1 yr?1 or greater. Finally, we demonstrate that approximately 71.8% of the boreal forest experiences Nr deposition rates at or below 3 kg ha?1 yr?1, suggesting that bryophytes likely limit woody plant acquisition of ambient anthropogenic Nr inputs throughout a majority of the boreal forest. 相似文献
16.
Phosphoenolpyruvate carboxylase activity in extracts of a wide range of thermogenic tissues of the Araceae was shown to be in the range 10–100 mol g-1 fresh weight min-1 (0.5–3.7 mol mg-1 protein min-1). Such high activities were not found in non-thermogenic tissues of the Araceae or in thermogenic tissues of Aristolochia brasiliensis Mart. and Zucc., Victoria amazonica Schomb. and Encephalartos barteri Carruth. During development and thermogenesis in the club of Arum maculatum L. the high activities of the carboxylase did not lead to any marked accumulation of citrate, isocitrate, 2-oxoglutarate, fumarate, malate and oxaloacetate. Clubs of Arum maculatum and of Arum italicum Miller readily fixed 14CO2 in the dark, mostly into aspartate, malate, alanine and glutamate. Pulse and chase experiments showed that most of the fixed carbon was very rapidly metabolized to CO2. The detailed distribution suggest that this occurred largely by decarboxylation of C-4 acids. It is suggested that thermogenic tissues of the Araceae are characterized by very high activities of phosphoenolpyruvate carboxylase, and that in vivo this leads to synthesis of C-4 acids which are promptly decarboxylated. 相似文献
17.
Vladimir Chalupa 《Plant cell reports》1990,9(7):398-401
Embryogenic cultures and somatic embryos were obtained from immature zygotic embryos of oak (Quercus robur L.) cultured on a modified MS medium and WPM containing BAP (1 mg·l–1) and GA3 (1 mg·l–1) or BAP and IBA. Germination and conversion of oak somatic embryos into plantlets was achieved on WPM containing a reduced concentration of cytokinin. Linden (Tilia cordata Mill.) somatic embryos developed in embryogenic tissues initiated from immature zygotic embryos cultured on a modified MS medium supplemented with 2,4-D (0.3-2.0 mg·l–1). Germination of linden somatic embryos and plantlet formation occurred on MS medium containing a low concentration of IBA. Oak and linden plantlets produced from somatic embryos were successfully established in soil. Somatic embryos and plantlets were also regenerated from embryogenic cultures of Quercus petraea and Tilia platyphyllos.Abbreviations BAP
6-benzyIaminopurine
- GA3
gibberellic acid
- IBA
indole-3-butyric acid
- 2,4-D
2,4-dichlorophenoxyacetic acid
- MS
Murashige and Skoog (1962)
- WPM
woody plant medium 相似文献
18.
Lubov P. Ryazanova Natalia E. Suzina Tatiana V. Kulakovskaya Igor S. Kulaev 《Archives of microbiology》2009,191(5):467-471
The cells of Acetobacter xylinum decreased phosphate concentration in the medium from 5 to 2.5 or 0.3 mM during incubation in the presence of Mg2+ and glucose, or Mg2+ and casamino acids, respectively. The prevalence of orthophosphate or polyphosphate in the biomass of A. xylinum depends on the medium composition. Under phosphate uptake in the presence of glucose, the content of orthophosphate in the
biomass changed little, while that of polyphosphate increased fourfold. At incubation with casamino acids, the content of
orthophosphate increased 15 times, while that of polyphosphate increased only 2.5 times. Some part of orthophosphate in this
case seems to be bound with the cell surface. The polyphosphate chain length in the cells of A. xylinim increases under phosphate uptake. This increase is more noticeable in the presence of glucose. Casamino acids can be replaced
by α-ketoglutaric acid in combination with (NH4)2SO4, or arginine, or glutamine, the catabolism of which results in formation of NH4
+ and α-ketoglutarate. 相似文献
19.
The uptake and metabolism of α-ketoglutarate-5-14C by peach, apple, and privet root tissues were studied over various time intervals. As much as 80% of the absorbed 14C appeared as 14CO2 in 320 minutes in peach roots. Apple and privet roots were less effective in this conversion with the bulk of the 14C found in the organic acid fraction. This indicates differences in organic acid metabolism among species of woody plants.
The 14C accumulated in malate earlier and in larger quantities than in citrate. Both glutamate and aspartate were labeled in 10 minutes and glutamate was labeled as early as 3 minutes. The labeling pattern does not clearly distinguish between the synthesis of glutamate by glutamic dehydrogenase or by transamination with oxaloacetate.
The rapid metabolism of α-ketoglutarate to glutamate by the 3 species studied indicates the presence of enzyme systems important in amino acid synthesis in the roots of woody plants.
相似文献20.
Growth and triterpenic acid accumulation of Cyclocarya paliurus cell suspension cultures 总被引:1,自引:0,他引:1
Zhongping Yin Xinchen Shangguan Jiguang Chen Qiang Zhao Dongming Li 《Biotechnology and Bioprocess Engineering》2013,18(3):606-614
Cyclocarya paliurus is a unique plant growing in central China with hypoglycaemic and hypolipaemia effects. To make better use of this functional food resource, cell suspension cultures and triterpenic acid accumulation were studied. Stable and uniform cell suspension cultures were established in liquid basal Murashige and Skoog medium supplemented with 2,4-dichlorophenoxy acetic acid (0.5 mg/L), naphthalene acetic acid (0.3 mg/L) and cytokinin (1.0 mg/L). According to the growth curve and triterpenic acid accumulation curve, the 8 ~ 10th day postinoculation was the optimum time for subculture, and the 14th day was the optimum time for harvest. Murashige and Skoog medium and woody plant medium were suitable for both cell growth and triterpenic acid accumulation. 3% sucrose (w/v), 60 mM total nitrogen (NO3 ?/NH4 + = 2/1), 1.25 mM KH2PO4, 2 mM CaCl2, and 2 mM MgSO4 were all found to be fit for cell growth and triterpenic acid accumulation in a cell suspension culture of Cyclocarya paliurus. Total triterpenic acid, ursolic acid and oleanolic acid content in suspended cultured cells were all significantly higher than that of leaves and calluses (P ? 0.01), with levels up to 6.24, 2.28, and 0.94% (of dry weight), respectively. The betulinic acid content of suspended cultured cells also reached 0.82%, which was significantly higher than that of calluses. These results suggest that suspended cultured cells of Cyclocarya paliurus were rich in triterpenic acids and could be used for the production of total triterpenic acid, ursolic acid, oleanolic acid and betulinic acid. 相似文献