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1.
A.-K. J. Sallal 《World journal of microbiology & biotechnology》1995,11(6):649-653
Gibberellic acid at 10-4
Mxxx was optimal for enhancement of growth, O2 evolution, photosystem II and I and the activity of glycollate dehydrogenase of Anacystis nidulans. A stimulatory effect was observed on photosystem II. Other concentrations of gibberellic acid were inhibitory to O2 evolution and photosystem I. Syntheses of phycocyanin, phycoerythrin and -carotene were significantly enhanced after 48 h incubation with gibberellic acid at 10-3
Mxxx but the chlorophyll content began to increase 3 h after adding 10-4
Mxxx gibberellic acid.The author is with the Department of Biological Sciences, Faculty of Science, University of Science and Technology, Irbid, Jordan. 相似文献
2.
Yasushi Shigemori Junko Inagaki Hitoshi Mori Mikio Nishimura Sumio Takahashi Yasusi Yamamoto 《Plant molecular biology》1994,24(1):209-215
A cDNA clone for the extrinsic 30 kDa protein (OEC30) of photosystem II in Euglena gracilis Z was isolated and characterized. The open reading frame of the cDNA encoded a polypeptide of 338 amino acids, which consisted of a long presequence of 93 amino acids and a mature polypeptide of 245 amino acids. Two hydrophobic domains were identified in the presequence, in contrast to the presence of a single hydrophobic domain in the presequence of the corresponding proteins from higher plants. At the N- and C-terminal regions, respectively, of the presequence, a signal-peptide-like sequence and a thylakoid-transfer domain were identified. The presence of a long and unique presequence in the precursor to OEC30 is probably related to the complexity of the intracellular processes required for the synthesis and/or transport of the protein in Euglena.Abbreviations ER
endoplasmic reticulum
- cDNA
complementary DNA
- SSU
small subunit; Rubisco, ribulose 1,5-bisphosphate carboxylase/oxygenase
- Rubico, ribulose 1,5
bisphosphate carboxylase/oxygenase
- LHC II
light-harvesting chlorophyll protein of photosystem II
- PS II
photosystem II
- OEC30
the extrinsic 30 kDa protein of photosystem II in Euglena
- PCR
polymerase chain reaction
- SDS
sodium dodecyl sulfate
- TE
a solution containing 10 mM Tris-HCl and 1 mM EDTA pH 8.0
- SSPE
a solution containing 0.15 M NaCl, 10 mM NaH2PO4 and 1 mM EDTA pH 7.4
- SDS-PAGE
sodium dodecyl sulfate-polyacrylamide gel electrophoresis
- PVDF
poly(vinylidene difluoride) 相似文献
3.
The addition of antimycin A during the logarithmic phase of growth of heterotrophic Euglena gracilis cultures (in lactate or glucose medium) was immediately followed by decreased respiration and a cessation of grwoth. Induced cyanideresistent respiration appeared 5 h after the addition of the inhibitor then the cells started to grow again and could be cultured in the presence of antimycin A. Thus the cells exhibited a cyanide-and antimycin-resistant respiration which was, in addition, sensitive to salicylhydroxamic acid and propylgallate. Antimycin-adapted Euglena and control cells were compared for their biomass production and protein synthesis. The difference in growth yield between control and antimycin-adapted cells was not as high as would be expected if only the first phosphorylation site of the normal respiratory chain was active in the presence of antimycin A. Furthermore, the ability to incorporate labelled valine into proteins, under resting-cell conditions, was not changed. Strong correlations were established between the effects of respiratory effectors on O2 consumption and valine incorporation. These results suggest that sufficient energy for protein synthesis and growth is provided by the operation of the cyanide-resistant respiratory pathway in antimycin-adapted Euglena.Abbreviations DNP
dinitrophenol
- PG
propylgallate
- SHAM
salicylhydroxamic acid 相似文献
4.
Different methods were tested to isolate protoplasts from etiolated, partially greened, and light-grown leaves of Avena sativa. Preparations with high yields and high photosynthetic capacities (time of illumination 4 h) were obtained when small transverse leaf segments were incubated for 2 h at 30°C in 2% cellulysin (Calbiochem), 0.6 M mannitol, and 0.5% bovine serum albumin (BSA) at pH 5.6, without shaking. As measured by light-dependent O2 evolution or fixation of labeled bicarbonate, protoplasts exhibited rates of up to 124 mol per mg of chlorophyll per h at 20°C and saturating bicarbonate, which were nearly identical to those found with intact leaves. The assay conditions necessary for this activity were 0.6 M sorbitol, 50 mM N-2-hydroxy-ethylpiperazine-N-2-ethane sulfonic acid (pH 7.6), and 10 mM NaHCO3. If plastids were isolated from these protoplasts, sorbitol was 0.45 M, including 10 mM ethylenediaminetetraacetate (EDTA). under these conditions, rates of photosynthesis were up to 125 (light-grown) and 71 (6 h illuminated) mol O2 evolved or 14CO2 fixed per mg of chlorophyll per h, compared to 3.5 mol·mg chl-1·h-1 obtained with mechanically isolated plastids. With this system, CO2-dependent O2 evolution was already detected after 3 h of illumination of etiolated tissue, but could only be observed at pH values between 7.6 and 8.6, in the presence of EDTA. At lower pH (7.3) or at pH 7.6 in the absence of EDTA, light-dependent O2 evolution up to 24 h of greening was only measurable with 3-phosphoglycerate as the substrate. The possible effects of EDTA in this respect as well as the advantages of using protoplasts or plastids isolated from protoplasts for developmental studies are discussed.Abbreviations BSA
bovine serum albumin
- EDTA
ethylenediamine tetraacetic acid
- HEPES
N-2-hydroxyethyl-piperazine-N-2-ethane-sulphonic acid
- MES
2(N-morpholino) ethane sulphonic acid
- PGA
3-phosphoglycerate 相似文献
5.
Summary Pokeweed (Phytolacca americana L.) and endod (P. dodecandra L'Herit) produce ribosome-inactivating proteins which are sequestered in leaf cell walls. These proteins display strong antiviral activity. To aid in studying the antiviral mechanism, we developed protocols to isolate protoplasts from suspension culture cells and leaves. Ninety-five percent of pokeweed or endod culture cells were converted to protoplasts using 2% cellulase, 0.25% pectinase, 0.2 M mannitol, 2% sucrose, 15 mM CaCl2 Murashige and Skoog salts, pH 5.7. Viability was >85% after 24 h. Culture-derived protoplasts were purified by centrifugation through a 15% sucrose pad. Protoplasts collected from the supernatant were then pelleted in 0.3 M mannitol. Pokeweed leaves provided respectable yields (4×106 protoplasts/g f w) of partially-purified viable protoplasts when digested in solution containing 1% cellulase, 0.2% Pectolyase, 0.4 M mannitol, CPW salts, 0.5 mM MES, pH 5.6. We were unable to completely separate cell debris from mesophyll protoplasts, which were small and easily damaged by centrifugation. Endod leaves were found to be resilient to several digestion enzymes tested. 相似文献
6.
Callus production from willow (Salix viminalis L.) protoplasts 总被引:2,自引:0,他引:2
Protoplasts were isolated from cell suspensions of Salix viminalis (basket willow) clone 78-0-90 and S. schwerinii clone 77-0-77, using cellulysin and macerase in modified Woody Plant medium. For clone 78-0-90, 6.3 · 106 ± 1.9 · 106 protoplasts were obtained per gram fresh weight. Cell divisions started two days after protoplast isolation and gave rise to callus which has been maintained in culture for up to four years. Protoplast yield from the clone 77-0-77 was lower (less than 106 protoplasts per gram cells), cell division was infrequent and no callus was obtained. Protoplasts were also isolated from the leaves of willow shoot cultures using cellulysin and pectolyase, but these did not show cell divisions.Abbreviations BA
benzyladenine
- 2,4-D
2,4-dichlorophenoxyacetic acid
- MS medium
Murashige & Skoog (1962) medium
- WP medium
Woody Plant medium (Lloyd & McCown 1981) 相似文献
7.
C. D’Onofrio S. Morini C. Vitagliano 《In vitro cellular & developmental biology. Plant》1999,35(5):421-423
Summary The aim of this research was to isolate protoplasts from in vitro-grown quince BA 29 leaves. Effects of various concentrations
of cellulase and pectinase and different incubation periods were evaluated. The most effective treatment included (per ml)
50 units cellulase and 10 units pectinase, in the incubation medium and incubation for 21 h at 50 rpm in the dark at 27°C.
This treatment produced a protoplast yield of 8.2×107 gfw−1 of which 90% were viable. Protoplast viability was influenced by length of the incubation period and ranged from about 40
to 100% among the various experiments. 相似文献
8.
Pyridazinone herbicides, SANDOZ 9785 (4-chloro-5-dimethylamino2-phenyl-3-(2H) pyridazinone), SANDOZ 9789 (4-chloro-5 (methylamino)-2-(α,
α, α-trifluoro-m-tolyl-3-(2H) pyridazinone) and SANDOZ 6706 (4-chloro-5-(methylamino)-2-(α, α, α-trifluoro-m-tolyl-3-(2H)
pyridazinone) inhibited photosystem II electron transport inChlorella protothecoides, when the herbicides were added to the assay medium. The inhibitory eficiency varied with the algal species and the nature
of substitution of pyridazinones. Using 3 algal systemsviz., Chlorella, Scenedesmus andAnacystis, the I50 value of for the inhibition of photosynthesis of 3 substituted pyridazinones (SANDOZ 9785, SANDOZ 6706 and SANDOZ 9789) were
determined. SANDOZ 9789 was found to be the weakest inhibitor of photosystem II electron transport (H2O→ benzoquinone) as compared to SANDOZ 9785 and SANDOZ 6706. In general, the order of inhibition could be given as SANDOZ
6706 >- SANDOZ 9785 > SANDOZ 9789. The I50 value of photosynthetic particles obtained fromChlorella cells was similar to that of whole cells, suggesting that the cell wall ofChlorella did not act as a barrier for the herbicide action. Studies on the light intensity dependence of SANDOZ 9785 inhibition of
electron transport (H2O→ benzoquinone) showed that the light-dependent portion of the curve was more sensitive than the light independent portion
of the curve. It is suggested that the site of action was on the reducing side of photosystem II. 相似文献
9.
Kuhad Ramesh Chander Kapoor Mukesh Rustagi Renuka 《World journal of microbiology & biotechnology》2004,20(3):257-263
An alkalophilic Streptomyces sp. RCK-SC, which produced a thermostable alkaline pectinase, was isolated from soil samples. Pectinase production at 45
°C in shaking conditions (200 rev min−1) was optimal (76,000 IU l−1) when a combination of glucose (0.25% w/v) and citrus pectin (0.25% w/v) was added along with urea (0.25% w/v) in the basal
medium devoid of yeast extract and peptone. All the tested amino acids and vitamins greatly induced pectinase production and
increased the specific productivity of pectinase up to 550%. In an immobilized cell system containing polyurethane foam (PUF),
the pectinase production was enhanced by 32% (101,000 IU l−1) compared to shake flask cultures. In solid-state cultivation (SSC) conditions, using wheat bran as solid substrate, pectinase
yield of 4857 IU g−1 dry substrate was obtained at substrate-to-moisture ratio of 1:5 after 72 h of incubation. The partially purified pectinase
was optimally active at 60 °C and retained 80% of its activity at 50 °C after 2 h of incubation. The half life of pectinase
was 3 h at 70 °C. Pectinase was stable at alkaline pH ranging from 6.0 to 9.0 for more than 8 h at room temperature retaining
more than 50% of its activity.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
10.
The apoproteins of the light-harvesting chlorophyll-protein complexes LHCI and CP29 (apparent molecular weights of 27 kDa and 29 kDa, respectively) of Euglena gracilis were identified immunologically. Both complexes are present in the thylakoids of autotrophically cultured Euglena cells during the whole cell cycle. The relative amount of each apoprotein tends to increase towards the end of the cell cycle. The light-harvesting chlorophyll-protein complex of photosystem II, LHCII, of E. gracilis contains chlorophyll a, chlorophyll b, neoxanthin, diadinoxanthin and beta-carotene. Its chlorophyll a/b ratio is about 1.7 during the whole cell cycle. About 9 h after cell division the ratio of diadinoxanthin to chlorophyll a is doubled for a time of 3–4 h. The relevance of this increase during one developmental stage is discussed in relation to the insertion and-or assembly of newly synthesized LHCII.Abbreviations LHCP
light-harvesting chlorophyll-protein complex
- PS
photosystem
This research was partly supported by the Deutsche Forschungsge meinschaft. 相似文献
11.
Light induction of chloroplast development in Euglena leads to quantitative changes in the protein composition of the soluble cell part. One major part of these is the observed accumulation of ribulose-1.5-bisphosphate carboxylase/oxygenase (RuBPCase) enzyme (EC 4.1.1.39). As measured by immunoelectrophoresis, a small amount of RuBPCase (about 10-6 pmol) is present in a dark-grown cell, whereas a greening cell (72h) contains 10–20 pmol enzyme. Both the cytoplasmic and chloroplastic translation inhibitors, cycloheximide and spectinomycin, have a strong inhibitory effect on the synthesis of the enzyme throughout the greening process of Euglena cells. Electrophoretic and immunological analyses of the soluble phase prepared from etiolated or greening cells do not show the presence of free subunits of the enzyme. For each antibiotic-treated greening cell, the syntheses of both subunits are blocked. Our data indicate that tight reciprocal control between the syntheses of the two classes of subunits occurs in Euglena. In particular, the RuBPCase small subunit synthesis in greening Euglena seems more dependent on the protein synthesis activity of the chloroplast than the syntheses of other stromal proteins from cytoplasmic origin.Abbreviations LSU
large subunit of ribulose-1.5-bisphosphate carboxylase
- RuBP
ribulose-1.5-bisphosphate
- RuBP-Case
ribulose-1.5-bisphosphate carboxylase
- SSU
small subunit of ribulose-1.5-bisphosphate carboxylase 相似文献
12.
Sequential actions of pectinases and cellulases during secretory cavity formation in Citrus fruits 总被引:1,自引:0,他引:1
Pectinase and cellulase activities are involved in a number of intercellular space-forming processes in plants. In this study,
we combined cytochemistry with ultrastructural analysis to investigate the ontogeny of secretory cavity in fruits of Citrus medica L. var. sarcodactylis (Noot.) Swingle, Citrus reticulata Blanco and Citrus limon (L.) Burm. f. Pectinase activity was first detectable at the initial stage of cavity formation, peaked at the intercellular
space-forming stage, and diminished at the following stages. In comparison, no cellulase activity was detected until the early
lumen-expanding stage. The cellulase activity increased at the late lumen-expanding stage and culminated at the near-mature
stage. In the fruit of C. medica var. sarcodactylis, the distribution of pectinase and cellulase reaction products was restricted to the endoplasmic reticulum (ER), the vesicles
derived from ER and the cell wall. We also observed that multivesicular structure containing the pectinase reaction product
at the initial stage of cavity formation. Our results suggest that pectinase and cellulase are synthesized on ER and secreted
directly into the cell wall through exocytosis of ER-derived vesicles. Our observations are consistent with the notion that
the secretory cavity in Citrus fruits is formed through a schizolysigenous process in which pectinase activity is involved in the degradation of the middle
lamella, whereas cellulase activity is responsible for the degradation of the cell wall. 相似文献
13.
Mohammad Vatanparast Vahid Hosseininaveh Mohammad Ghadamyari Seyede Minoo Sajjadian 《Journal of Asia》2012,15(4):555-561
The elm leaf beetle, Xanthogaleruca luteola, is a serious pest of elm trees in urban areas. Partial biochemical characterization of pectinases and cellulases was conducted using the larval digestive system of the pest. Midgut extracts from larvae showed optimum activity for pectinase and cellulase against pectin and carboxymethyl cellulose, respectively, under acidic conditions (pH 6). Pectinases and cellulases were respectively more stable under acidic conditions (pH 4–7) and slightly acidic conditions (pH 5–7) than under highly acidic and alkaline conditions. However, the enzymes were more stable in slightly acidic conditions (pH 6) when incubation time was increased. Maximum activity for the pectinases and cellulases incubated at different temperatures was observed at 45 and 50 °C, respectively. Mg2+ remarkably increased pectinase activity, and cellulase activity increased significantly in the presence of Ca2+ and Mg2+. Sodium dodecyl sulfate significantly decreased pectinase and cellulase activity. The Michaelis–Menten constant (KM) and the maximal reaction velocity (Vmax) values for pectinase were 2 mg·mL? 1 and 0.017 mmol·min? 1·mg? 1 protein toward pectin, respectively. Zymogram analyses revealed the presence of one and five bands of pectinase and cellulase activity, respectively, in the larval midgut extract. 相似文献
14.
Optimization of multienzyme production by two mixed strains in solid-state fermentation 总被引:3,自引:0,他引:3
F3 and F4 strains of Aspergillus niger were screened from five strains of fungi to produce multienzyme preparations (containing cellulase, hemicellulase, glucoamylase, pectinase, and acidic proteinase) as dietary supplementation. Enzyme activities indicated that 1:4 (F3 to F4) was the optimum mixture proportion, and 0.3% (W/W) was the preferable pitching rate. In bran mash containing 54.5% (W/W) water, F3 and F4 could produce the supplementation better when cultured 30 to 36 h at 30 °C. Monofactorial and orthogonal experiments were performed to optimize media. Results of the variance and range analysis showed that the optimum medium contained 80 g of bran, 20 g of cottonseed powder, 1 g of (NH4)2SO4, and 0.1 g of KH2PO4. When F3 and F4 strains were cultured in the optimum medium containing 54.5% (W/W) water, the activity of cellulase, hemicellulase, glucoamylase, pectinase, and acidic proteinase reached 996; 15,863; 13,378; 7,621; and 5,583 U/g, respectively. 相似文献
15.
16.
The crude extracellular cellulase from Clostridium thermocellum was oxidatively inactivated by air and inhibited by sulfhydryl reagents. Activity-loss was prevented and reversed by the addition of a high concentration (10 mM) dithiothreitol (DDT) at zero time and up to 24 h respectively. In the presence of a low concentration (0.4 mM) of DTT, the enzyme was more rapidly inactivated than in air alone. This was probably due to autoxidation of the low DTT concentration to H2O2 as shown by its prevention by a high DTT concentration, exclusion of air, or catalase; and by the oxidative inactivation of the enzyme by H2O2. The inactivation by H2O2 could be prevented by a high concentration of DTT but not by air exclusion. EDTA protected the enzyme from inactivation in air by a low concentration of DTT or by H2O2. This is presumably due to the role of metals in oxidation of SH groups. Furthermore, copper (5 M) also caused inactivation and this was prevented by the presence of a high DTT concentration. Even in the protective atmosphere of a high DTT concentration, cellulase was inactivated by certain apolar chelating agents such as o-phenanthroline and -1-dipyridyl, such inactivation being preventable by the prior incubation of the chelator with a mixture of Fe2+ and Fe3+. These data suggest that the clostridial cellulase, unlike the enzyme from aerobic fungi, contains essential sulfhydryl groups and is stimulated by iron. The endo--glucanase component of the cellulase complex was not susceptible to oxidative inactivation.Abbreviations DTT
dithiothreitol
- CMC
carboxymethylcellulose
- DTNB
5,5-dithiobis-(2-nitrobenzoic acid)
- NEM
N-ethylmaleimide
-
p-CMB
p-chloromercuribenzoic acid 相似文献
17.
Treatment of spheroplasts of Nostoc museorum with hypotonic buffer results in membranes depleted of cytochrome c-553, but still active in photosynthetic and respiratory electron transport. These membranes retain full photosystem II activity (H2ODADox). Complete linear electron transport (H2ONADP+), however, is decreased as compared with untreated spheroplasts. Addition of basic Nostoc cytochrome c-553 to depleted membranes reconstitutes NADP+ reduction and redox reactions of the photosystem I region as well.Using NADPH as electron donor, respiration of depleted membranes is also stimulated by adding cytochrome c-553, indicative of its function in respiratory electron transport.Cytochrome c-553 from Bumilleriopsis filiformis, Spirulina platensis (acidic types), Phormidium foveolarum (basic type), and mitochondrial horse-heart cytochrome c-550 are not effective in reconstituting both photosynthetic and respiratory electron transport, which points to a specific role of Nostoc cytochrome c-553.Abbreviations BSA
bovine serum albumin
- DAD
3,6-diaminodurene
- DADox
3,6-diaminodurene oxidized by potassium ferricyanide
- DBMIB
2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone
- DCMU
3-(3,4-dichlorophenyl)-1,1-dimethylurea
- DCIP
2,6-dichlorophenolindophenol
- DPC
1,5-diphenylcarbazide
- Fd
ferredoxin
- HEPES
N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid
- MES
2(-N-morpholino)-ethanesulfonic acid
- MV
methylviologen (1,1-dimethyl-4,4-bipyridylium dichloride)
- PS I
photosystem I
- PS II
photosystem II
- Tris
tris-(hydroxymethyl)-aminomethane 相似文献
18.
Einicker-Lamas M Morales MM Miranda K Garcia-Abreu J Oliveira AJ Silva FL Oliveira MM 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2003,173(7):559-564
Selective pressures from polluted environments have led to the development of resistance systems in aquatic organisms. Using different techniques, this study examined a cadmium defense mechanism of the freshwater unicellular protozoa Euglena gracilis, and found it to be an efflux pump similar to the multidrug resistance P-glycoprotein. Cd2+-treated E. gracilis were able to extrude Rhodamine 123 at 21 °C, but not at 4 °C. Furthermore, verapamil, a P-glycoprotein modulator, partially blocked the efflux process (at 21 °C), and enhanced the Cd2+ toxic effects on these cells. Western immunoblots of cell lysates, using the anti-P-glycoprotein antibody JSB-1, revealed a 120-KDa protein, which was expressed, in high amounts on Cd2+-exposed cells (74% above the control values). Moreover, cells treated with JSB-1 became more sensitive to the harmful effects of cadmium, showing a decreased survival rate. Taken together, these results suggest that a MDR phenotype has evolved in Euglena as one of the mechanisms for cadmium detoxification.Abbreviations DTT dithiothreitol - mAb JSB-1 anti-human P-gp monoclonal antibody JSB-1 - MDR multidrug resistance - MRP MDR-associated protein - PBS phosphate buffered saline - P-gp P-glycoproteinCommunicated by G. HeldmaierA.J.F.O. and F.L.S.S. are undergraduate students under a CNPq special program for research training 相似文献
19.
Sophorose metabolism and cellulase induction in Trichoderma 总被引:6,自引:0,他引:6
The cellulase inducer sophorose was rapidly catabolized to CO2 and H2O by Trichoderma: only small amounts were used to induce the synthesis of cellulase. 3H-sophorose uptake began after a lag of 1 h and its half-life in the medium was less than 5 h. Cellulase activity in the medium did not increase till 6 h after the addition of sophorose and reached a half maximum value at 14 h. The presence of free sophorose in the medium was required for continuous cellulase production. Several small sophorose addition induced much more cellulase than an equivalent single dose. These results are attributed to two pathways of sophorose utilization, a catabolic pathway that has a high capacity but low affinity for sophorose and an inductive pathway having a lower capacity but higher affinity for sophorose. 相似文献
20.
Thylakoids isolated from peas (Pisum sativum cv. Kelvedon Wonder) and phosphorylated by incubation with ATP have been compared with non-phosphorylated thylakoids in their sensitivity to photoinhibition by exposure to illumination in vitro. Assays of the kinetics of fluorescence induction at 20° C and the fluorescence emission spectra at-196° C indicate a proportionally larger decrease in fluorescence as a result of photoinhibitory treatment of non-phosphorylated compared with phosphorylated thylakoids. It is concluded that protein phosphorylation can afford partial protection to thylakoids exposed to photoinhibitory conditions.Abbreviations and symbols DCMU
3-(3,4-dichlorophenyl)-1,1-dimethylurea
-
F
0
Level of chlorophyll fluorescence when photosystem 2 traps are open
-
F
m
Level of chlorphyll fluorescence when photosystem 2 traps are closed
- P
Maximum level of fluorescence reached in the absence of DCMU
- PSI (II)
photosystem I(II) 相似文献