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1.
T. Zhang 《In vitro cellular & developmental biology. Plant》2007,43(2):91-94
This study investigated the factors affecting in vitro flowering of Perilla frutescens. The shoots regenerated from cotyledonary and hypocotyl explants cultured on Murashige and Skoog (MS) medium supplemented
with benzyladenine (BA) and indole-3-acetic acid, each at 0.5 mg l−1, were excised and transferred to MS medium containing 30 g l−1 of sucrose, 8.25 g l−1 of ammonium nitrate, and 1.0 mg l−1 of BA. After 40 d of culture, 86.2% of shoots flowered and most of which self-fertilized in vitro and produced mature fruits with viable seeds. These seeds were germinated and plants were grown to maturity and flowered
in soil under greenhouse conditions. The in vitro flowering system reported in this study may facilitate rapid breeding of P. frutescens and offers a model system for studying the physiological mechanism of flowering. 相似文献
2.
Two oligosaccharides, a heptasaccharide (HS) and an octasaccharide (OS), isolated from Paris polyphylla var. yunnanensis, stimulated the growth and saponin accumulation of Panax ginseng hairy roots at 5–30 mg l−1. HS and OS at 30 mg l−1, fed separately to hairy root cultures at 10 days post-inoculation, increased the root biomass dry weight by more than 70%
to ∼20 g l−1 from 13 g l−1 and the total saponin content of roots by more than 1-fold to ∼3.5% from 1.6% (w/w). The results suggest that the two oligosaccharides
may have plant growth-regulatory activity in plant tissue cultures. 相似文献
3.
Two new effective microbial producers of inulinases were isolated from Jerusalem artichoke tubers grown in Thailand and identified
as Aspergillus niger TISTR 3570 and Candida
guilliermondii TISTR 5844. The inulinases produced by both these microorganisms were appropriate for hydrolysing inulin to fructose as the
principal product. An initial inulin concentration of ∼100 g l−1 and the enzyme concentration of 0.2 U g−1 of substrate, yielded 37.5 g l−1 of fructose in 20 h at 40°C when A. niger TISTR 3570 inulinase was the biocatalyst. The yield of fructose on inulin was 0.39 g g−1. Under identical conditions, the yeast inulinase afforded 35.3 g l−1 of fructose in 25 h. The fructose yield was 0.35 g g−1 of substrate. The fructose productivities were 1.9 g l−1 h−1 and 1.4 g l−1 h−1 for the mold and yeast enzymes, respectively. After 20 h of reaction, the mold enzyme hydrolysate contained 53% fructose
and more than 41% of initial inulin had been hydrolysed. Using the yeast enzymes, the hydrolysate contained nearly 38% fructose
at 25 h and nearly 36% of initial inulin had been hydrolysed. The A. niger TISTR 3570 inulinases exhibited both endo-inulinase and exo-inulinase activities. In contrast, the yeast inulinases displayed
mainly exo-inulinase activity. The mold and yeast crude inulinases mixed in the activity ratio of 5:1 proved superior to individual
crude inulinases in hydrolysing inulin to fructose. The enzyme mixture provided a better combination of endo- and exo-inulinase
activities than did the crude extracts of either the mold or the yeast individually. 相似文献
4.
To screen stimulators from Chinese medicinal insects for mycelial growth and polysaccharides production of Ganoderma lucidum, G. lucidum was inoculated into the media with and without supplementation of medicinal insect extracts. The ethyl acetate extract of
Eupolyphaga sinensis at 55 mg l−1 lead to significant increase in both biomass and intracellular polysaccharides (IPS) concentration from 8.53 ± 0.41 to 14.16 ± 0.43
and 1.28 ± 0.09 to 2.13 ± 0.11 g l−1, respectively. In addition, the ethyl acetate extract of Catharsius molossus at 55 mg l−1 significantly enhanced extracellular polysaccharides (EPS) production; the EPS yield increased from 350.9 ± 14.1 to 475.1 ± 15.3 mg
l−1. There were no new components in the two types of polysaccharides obtained by the addition of the insect extracts. 相似文献
5.
A genetic transformation system has been developed for callus cells of Crataegus
aronia using Agrobacterium
tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with
5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different
types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red
colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli
were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this
is the first time to report an Agrobacterium-mediated transformation system in Crataegus
aronia. 相似文献
6.
The fadBA operon in the fatty acid β-oxidation pathway of P. putida KCTC1639 was blocked to induce a metabolic flux of the intermediates to the biosynthesis of medium chain-length PHA (mcl-PHA).
Succinate at 150 mg l−1 stimulated cell growth and also the biosynthesis of medium chain-length-polyhydroxyalkanoate. pH-stat fed-batch cultivation
of the fadA knockout mutant P. putida KCTC1639 was carried out for 60 h, in which mcl-PHA reached 8 g l−1 with a cell dry weight of 10.3 g l−1. 相似文献
7.
Zahir Ahmad Zahir Usman Ghani Muhammad Naveed Sajid Mahmood Nadeem Hafiz Naeem Asghar 《Archives of microbiology》2009,191(5):415-424
Ethylene synthesis is accelerated in response to various environmental stresses like salinity. Ten rhizobacterial strains
isolated from wheat rhizosphere taken from different salt affected areas were screened for growth promotion of wheat under
axenic conditions at 1, 5, 10 and 15 dS m−1. Three strains, i.e., Pseudomonas putida (N21), Pseudomonas aeruginosa (N39) and Serratia proteamaculans (M35) showing promising performance under axenic conditions were selected for a pot trial at 1.63 (original), 5, 10 and 15 dS m−1. Results showed that inoculation was effective even in the presence of higher salinity levels. P. putida was the most efficient strain compared to the other strains and significantly increased the plant height, root length, grain
yield, 100-grain weight and straw yield up to 52, 60, 76, 19 and 67%, respectively, over uninoculated control at 15 dS m−1. Similarly, chlorophyll content and K+/Na+ of leaves also increased by P. putida over control. It is highly likely that under salinity stress, 1-aminocyclopropane-1-carboxylic acid-deaminase activity of
these microbial strains might have caused reduction in the synthesis of stress (salt)-induced inhibitory levels of ethylene.
The results suggested that these strains could be employed for salinity tolerance in wheat; however, P. putida may have better prospects in stress alleviation/reduction. 相似文献
8.
Meiru Li Hongqing Li Huawu Jiang Guojiang Wu 《Plant Cell, Tissue and Organ Culture》2008,93(3):249-255
Broussonetia papyrifera is well-known for its bark fibers, which are used for making paper, cloth, rope etc. This is the first report of a successful
genetic transformation protocol for B. papyrifera using Agrobacterium tumefaciens. Callus was initiated at a frequency of about 100% for both leaf and petiole explants. Shoots formed on these calli with
a success rate of almost 100%, with 14.08 and 8.36 shoots regenerating from leave-derived and petiole-derived callus, respectively.
For genetic transformation, leaf explants of B. papyrifera were incubated with A. tumefaciens strain LBA4404 harboring the binary vector pCAMBIA 1301 which contains the hpt gene as a selectable marker for hygromycin resistance and an intron-containing β-glucuronidase gene (gus-int) as a reporter gene. Following co-cultivation, leaf explants were cultured on Murashige and Skoog (Physiol Plant 15:473,
1962) (MS) medium supplemented with 1.5 mg l−1 benzyladenine (BA) and 0.05 mg l−1 indole-3-butyric acid (IBA) (CI medium) containing 5 mg l−1 hygromycin and 500 mg l−1 cefotaxime, in the dark. Hygromycin-resistant calli were induced from leaf explants 3 weeks thereafter. Regenerating shoots
were obtained after transfer of the calli onto MS medium supplemented with 1.5 mg l−1 BA, 0.05 mg l−1 IBA, and 0.5 mg l−1 gibberellic acid (GA3) (SI medium), 5 mg l−1 hygromycin and 250 mg l−1 cefotaxime under fluorescent light. Finally, shoots were rooted on half strength MS medium (1/2 MS) supplemented with 10 mg l−1 hygromycin. Transgene incorporation and expression was confirmed by PCR, Southern hybridisation and histochemical GUS assay.
Using this protocol, transgenic B. papyrifera plants containing desirable new genes can be obtained in approximately 3 months with a transformation frequency as high as
44%. 相似文献
9.
Wen Liu Xuesen Chen Guanjun Liu Qing Liang Tianming He Jianrong Feng 《Plant Cell, Tissue and Organ Culture》2007,88(3):289-299
Embryo rescue technique was used successfully to produce interspecific hybrids by crossing peach (P. persica) as a female parent with apricot (P. armeniaca) and plum (P. salicica). In those crosses that had ‘Yuhualu’ or ‘Zhonghuashoutao’ as female parents, hybrid embryos aborted from the 7th or 8th
week after pollination mainly due to post-pollination incompatibility. An embryo rescue protocol was established to rescue
such embryos and recover hybrid plants. Modified half-strength MS medium containing 4 mg l−1 6-BA and 0.5 mg l−1 IBA produced up to 90% germination in the embryos. Modified MS medium with 1.0 mg l−1 6-BA and 1.0 mg l−1 IBA gave the highest bud induction and multiplication whereas modified MS medium containing 0.5 mg l−1 IAA and 0.2 mg l−1 NAA gave the best rooting percentage. All the hybrids obtained using this embryo rescue technique were verified using simple
sequence repeat (SSR) markers. A series of pollen treatments were carried out to partially overcome pre-pollination incompatibility,
and it was found accidentally that pollen treatment with electrostatic field not only improved pollen germination but also
increased the multiplication coefficient of embryo-induced shoots. 相似文献
10.
Summary
Dendrobium candidum Wall. Ex Lindl. is an important species used in the formulation of Shih-hu, a Chinese traditional medicine. An efficient
protocol for in vitro propagation of D. candidum using the axenic nodal segments of the shoots, originated from the in vitro germinated seedlings, was developed. The seeds from 120-d-old capsules after pollination were first germinated on half-strength
Murashige and Skoog (MS) basal medium supplemented with 30 g l−1 sucrose. After 4 mo., the seedlings were subcultured on a similar medium supplemented with 1 ml l−1 HYPONeX, 80 g l−1 potato homogenate and 2 g l−1 activated charcoal for further growth. Axenic nodal segments excised from 9-mo.-old seedlings were cultured on the medium
in the presence of 2 mg l−1 benzyladenine (BA) and 0.1 mg l−1 naphthaleneacetic acid (NAA). After 75 d, 73.2% of the explants gave rise to buds/shoots. The elongated shoots were rooted
on the medium containing 0.2 mg l−1 NAA and the plantlets were successfully acclimatized in soil. 相似文献
11.
Meiru Li Hongqing Li Huawu Jiang Xiaoping Pan Guojiang Wu 《Plant Cell, Tissue and Organ Culture》2008,92(2):173-181
Jatropha curcas contains high amounts of oil in its seed and has been considered for bio-diesel production. A transformation procedure for
J. curcas has been established for the first time via
Agrobacterium tumefaciens infection of cotyledon disc explants. The results indicated that the efficiency of transformation using the strain LBA4404
and phosphinothricin for selection was an improvement over that with the strain EHA105 and hygromycin. About 55% of the cotyledon
explants produced phosphinothricin-resistant calluses on Murashige and Skoog (MS) medium supplemented with 1.5 mg l−1 benzyladenine (BA), 0.05 mg l−1 3–indolebutyric acid (IBA), 1 mg l−1 phosphinothricin and 500 mg l−1 cefotaxime after 4 weeks. Shoots were regenerated following transfer of the resistant calli to shoot induction medium containing
1.5 mg l−1 BA, 0.05 mg l−1 IBA, 0.5 mg l−1 gibberellic acid (GA3), 1 mg l−1 phosphinothricin and 250 mg l−1 cefotaxime, and about 33% of the resistant calli differentiated into shoots. Finally, the resistant shoots were rooted on
1/2 MS media supplemented with 0.3 mg l−1 IBA at a rate of 78%. The transgenic nature of the transformants was demonstrated by the detection of β-glucuronidase activity
in the primary transformants and by PCR and Southern hybridization analysis. 13% of the total inoculated explants produced
transgenic plants after approximately 4 months. The procedure described will be useful for both, the introduction of desired
genes into J. curcas and the molecular analysis of gene function. 相似文献
12.
13.
Single-culture aerobic granules with <Emphasis Type="Italic">Acinetobacter calcoaceticus</Emphasis> 总被引:1,自引:0,他引:1
Aerobic granules are cultivated by a single bacterial strain, Acinetobacter calcoaceticus, in a sequencing batch reactor (SBR). This strain presents as a good phenol reducer and an efficient auto coagulator in the
presence of phenol, mediated by heat-sensitive adhesins proteins. Stable 2.3-mm granules were formed in the SBR following
a 7-week cultivation. These granules exhibit excellent settling attributes and degrade phenol efficiently at concentrations
of 250–2,000 mg l−1. The corresponding phenol degradation rate reached 993.6 mg phenol g−1 volatile suspended solids (VSS) day−1 at 250 mg l−1 phenol and 519.3 mg phenol g−1 VSS day−1 at 2,000 mg l−1 phenol concentration. Meanwhile, free A. calcoaceticus cells were fully inhibited at phenol >1,500 mg l−1. Denaturing gradient gel electrophoresis fingerprint profile demonstrated no genetic modification in the strain during aerobic
granulation. The present single-strain granules showed long-term structural stability and performed high phenol degrading
capacity and high phenol tolerance. The confocal laser scanning microscopic test revealed that live A. calcoaceticus cells principally distributed at 200–250 μm beneath the outer surface, with an extracellular polymeric substance layer covering
them to defend phenol toxicity. Autoaggregation assay tests demonstrated the possibly significant role of secreted proteins
on the formation of single-culture A. calcoaceticus granules. 相似文献
14.
Xylose reductase (XR) is a key enzyme in biological xylitol production, and most XRs have broad substrate specificities. During
xylitol production from biomass hydrolysate, non-specific XRs can reduce l-arabinose, which is the second-most abundant hemicellulosic sugar, to the undesirable byproduct arabitol, which interferes
with xylitol crystallization in downstream processing. To minimize the flux from l-arabinose to arabitol, the l-arabinose-preferring, endogenous XR was replaced by a d-xylose-preferring heterologous XR in Candida tropicalis. Then, Bacillus licheniformis
araA and Escherichia coli araB and araD were codon-optimized and expressed functionally in C. tropicalis for the efficient assimilation of l-arabinose. During xylitol fermentation, the control strains BSXDH-3 and KNV converted 9.9 g l-arabinose l−1 into 9.5 and 8.3 g arabitol l−1, respectively, whereas the recombinant strain JY consumed 10.5 g l-arabinose l−1 for cell growth without forming arabitol. Moreover, JY produced xylitol with 42 and 16% higher productivity than BSXDH-3
and KNV, respectively. 相似文献
15.
A. V. Loskutov G.-Q. Song K. C. Sink 《In vitro cellular & developmental biology. Plant》2008,44(4):239-245
Callus selection (CS) and the flamingo-bill explant (FB) methods were evaluated for efficacy in transformation for celery.
Agrobacterium tumefaciens strains EHA105 and GV3101, each with the bar gene under the promoters NOS (pGPTV-BAR) or 35S (pDHB321.1), were used. Leaf explants were inoculated and co-cultivated for
2 d in the dark. Calluses emerged on the explants on callus medium (C), Murashige and Skoog (MS) medium + 2,4-Dichlorophenoxyacetic
acid (2,4-D) (2.3 μM) + kinetin (2.8 μM) + timentin (300 mg·l−1). Calluses 4- to 6-wk-old were selected for glufosinate (GS) resistance by a two step method. First, calluses were transferred
to C medium + GS 0.35, 0.5, 1, 2, 5, or 10 mg·l−1; calluses formed only with 0, 0.35 and 0.5 mg·l−1 GS. All growing calluses from 0 and 0.35 mg·l−1 and a few from 0.5 mg·l−1, were divided and placed back on C + GS 0.35–0.5 mg·l−1 for another 5–6 wk. Second, tolerant clones were again divided and placed on C + GS 1–50 mg·l−1. When cultivar XP85 was inoculated with both strains, using pGPTVBAR, 19 glufosinate resistant (GR) callus clones were selected,
but shoots regenerated only for strain EHA105 inoculations. When both of the strains (each with pDHB321.1) were inoculated
on cv. XP166, 3 and 12 GR calluses occurred for EHA105 and GV3101, respectively. Using CS, a total of 34 GR callus clones
were selected, and shoots were regenerated from over 50% of them on Gamborg B5 medium + 6-(γ, γ-dimethylallylamino) purine
2ip (4.9 μM) + naphthaleneacetic acid (NAA; 1.6 μM) and rooted on MS in 5–6 mo total time. Conversely, using FB with inoculation
by GV3101/pDHB321.1 on cv. XP166 yielded putative transgenic celery plants confirmed by polymerase chain reaction (PCR) in
just 6 wk. Transformation of the bar gene into celery was confirmed by PCR for 5 and 6 CS and FB lines, respectively. Southern blot analyses indicated 1–2 copies
in CS lines and 1 copy in FB lines. Herbicide assays on whole plants with 100 and 300 mg·l−1 glufosinate indicated a range of low to high tolerance for lines derived by both methods. The bar gene was found to be Mendelian inherited in one self-fertile CS derived line. 相似文献
16.
Thellungiella halophila is a salt-tolerant close relative of Arabidopsis, which is adopted as a halophytic model for stress tolerance research. We established an Agrobacterium tumefaciens-mediated transformation procedure for T. halophila. Leaf explants of T. halophila were incubated with A. tumefaciens strain EHA105 containing a binary vector pCAMBIA1301 with the hpt gene as a selectable marker for hygromycin resistance and an intron-containing β-glucuronidase gene as a reporter gene. Following
co-cultivation, leaf explants were cultured on selective medium containing 10 mg l−1 hygromycin and 500 mg l−1 cefotaxime. Hygromycin-resistant calluses were induced from the leaf explants after 3 weeks. Shoot regeneration was achieved
after transferring the calluses onto fresh medium of the same composition. Finally, the shoots were rooted on half strength
MS basal medium supplemented with 10 mg l−1 hygromycin. Incorporation and expression of the transgenes were confirmed by PCR, Southern blot analysis and GUS histochemical
assay. Using this protocol, transgenic T. halophila plants can be obtained in approximately 2 months with a high transformation frequency of 26%. 相似文献
17.
A high-frequency and simple procedure for Agrobacterium tumefaciens-mediated genetic transformation of the medicinal plant Salvia miltiorrhiza was developed. Leaf discs were pre-cultured on MS medium supplemented with 6.6 μmol l−1 BAP and 0.5 μmol l−1 NAA for one day, then co-cultured with A. tumefaciens strain EHA105 harboring the plasmid pCAMBIA 2301 for three days on the same medium. Regenerated buds were obtained on selection
medium (co-culture medium supplemented with 60 mg l−1 kanamycin and 200 mg l−1 cefotaxime) after two cycles’ culture of 10 days each and then transferred to fresh MS medium with 60 mg l−1 kanamycin for rooting. Fifteen days later, the rooted plantlets were obtained and then successfully transplanted to soil.
The transgenic nature of the regenerated plants was confirmed by PCR, Southern hybridization analysis and GUS histochemical
assay. Averagely, 1.1 independent verified transgenics per explant plated were obtained through this protocol. Adopting this
procedure, positive transformed plants could be obtained within 2–3 months from mature seeds germination to transplant to
soil, and more than 1,000 transgenic plants with several engineered constructs encoding different genes of interest were produced
in our lab in the past two years. 相似文献
18.
We evaluated the combined effects of algal (Chlorella vulgaris) food levels (low, 0.5 × 106 (or 2.9 μg C ml−1); and high, 1 × 106 cells ml−1 (or 5.8 μg C ml−1)) and zinc concentrations (0, 0.125, and 0.250 mg l−1 of ZnCl2) on the competition between two common planktonic rotifers Anuraeopsis fissa and Brachionus rubens using their population growth. Median lethal concentration data (LC50) (mean ± 95% confidence intervals) showed that B. rubens was more resistant to zinc (0.554 ± 0.08 mg l−1) than A. fissa (0.315 ± 0.07 mg l−1). A. fissa when grown alone or with Zn was always numerically more abundant than B. rubens. When grown in the absence of zinc, under low- and high-food levels, the peak abundances of A. fissa varied from 251 ± 24 to 661 ± 77 ind. ml−1, respectively, and the corresponding maxima for B. rubens were 52 ± 3 and 102 ± 18 ind. ml−1. At a given food level, competition for food reduced the peak abundances of both rotifers considerably. Increase in Zn concentration
also lowered the rotifer abundances. The impact of zinc on competition between the two-rotifer species was evident at low-food
level, mainly for A. fissa. At zinc concentrations of 0 and 0.125 mg l−1, the populations of both rotifers continued to grow for about 10 days, but thereafter B. rubens began to decline. Role of zinc on the competitive outcome of the two species is discussed in relation to the changing algal
densities in natural water bodies. 相似文献
19.
K. Kapsopoulou A. Mourtzini M. Anthoulas E. Nerantzis 《World journal of microbiology & biotechnology》2007,23(5):735-739
Four mixed culture fermentations of grape must were carried out with Kluyveromyces thermotolerans strain TH941 and Saccharomyces cerevisiae strain SCM952. In the first culture, both yeasts were added together, whereas in the remaining three cultures S. cerevisiae was added 1, 2, and 3 days after the inoculation of K. thermotolerans. The growth and survival of the K. thermotolerans strain and the amount of the produced l-lactic acid depend on the time of inoculation of the S. cerevisiae strain and provided an effective acidification during alcoholic fermentation. The four cultures contained, respectively,
at the end of fermentation 0.18, 1.80, 4.28, and 5.13 g l-lactic acid l−1. The grape must with an initial pH of 3.50 was effectively acidified (70% increase in titratable acidity, 0.30 pH unit decrease)
by the production of 5.13 g l-lactic acid l−1. 相似文献
20.
The mycelia of Aspergillus niger, cultivated in a medium containing 45 g l−1 maltose, 66 g l−1 yeast extract, and 5 g l−1 K2HPO4 at 30°C and 200 rpm, were used as a biocatalyst in the glucosylation of ascorbic acid. Free mycelia from 3-day-old culture,
when used in a 6-h reaction with maltose as the acyl donor, gave 16.07 g l−1 ascorbic acid glucoside corresponding to a volumetric productivity of 2.68 g l−1 h−1 and a conversion of 67%. Mycelia from 3-day-old cultures were entrapped in calcium alginate beads and used as a catalyst
in the glucosylation of ascorbic acid. An ascorbic acid-to-maltose molar ratio of 1:9 was found to be optimum, and the conversion
reached 75% after 12 h. The concentration of ascorbic acid glucoside produced at this molar ratio was 17.95 g l−1, and the productivity was 1.5 g l−1 h−1. The biocatalyst was repeatedly used in a fixed bed bioreactor for the synthesis of ascorbic acid glucoside and approximately
17 g l−1 of ascorbic acid glucoside corresponding to a volumetric productivity of 1.42 g l−1 h−1 was produced in each use. The conversion was retained at 70% in each use. The entrapped mycelia also exhibited exceptionally
high reusability and storage stability. The product was purified to 85% by anion exchange and gel permeation chromatography
with a final yield of 75%. 相似文献