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1.
I. M. Johnstone 《American journal of botany》1978,65(6):608-614
Eight isolates of Draparnaldia from a variety of freshwater habitats were grown in unialgal, defined culture. The morphological responses of these isolates to different daylengths, light intensities and temperatures are described. The phenotypic expression of Draparnaldia is markedly modified by all three factors. The interaction of these environmental variables was highly significant, and it is not possible, in most cases, to describe or predict the morphological appearance of Draparnaldia by referring to one of these parameters in isolation. The adaptive significance of phenotypic plasticity in Draparnaldia is discussed. 相似文献
2.
Philip W. Cook 《Journal of phycology》1970,6(1):62-67
Draparnaldia champlainensis sp. nov. is described and compared with other species of the genus and with Draparnaldiopsis. It closely resembles certain species described by Meyer from Lake Baikal and also Draparnaldiopsis simplex Jao. Its distinguishing features are (1) determinate branches borne in whorls on nearly every cell of the main axis; (2) one or a few broad hairs originating near the base of the determinate branch system; (3) a well-defined group of meristematic cells at the base of the hair; and (4) extensive rhizoidal cortication in the lower portions of the plants and at the base of the main branches. Draparnaldiopsis simplex Jao is transferred to the genus Draparnaldia and renamed Draparnaldia jaoi nom. nov. 相似文献
3.
Männistö MK Tiirola MA Salkinoja-Salonen MS Kulomaa MS Puhakka JA 《Archives of microbiology》1999,171(3):189-197
Chlorophenol-degrading bacteria from a long-term polluted groundwater aquifer were characterized. All isolates degraded 2,4,6-trichlorophenol
and 2,3,4,6-tetrachlorophenol at concentrations detected in the contaminated groundwater (< 10 mg l–1). Pentachlorophenol was degraded by three isolates when present alone. In two gram-positive isolates, 2,3,4,6-tetrachlorophenol
was required as an inducer for the degradation of pentachlorophenol. The gram-positive isolates were sensitive to pentachlorophenol,
with an IC50 value of 5 mg/l. Isolates belonging to the Cytophaga/Flexibacter/Bacteroides phylum had IC50 values of 25 and 63 mg/l. Isolates belonging to α-, β- and γ-Proteobacteria generally tolerated the highest pentachlorophenol
concentrations (> 100 mg/l). Polychlorophenol-degrading capacity was found in strains of Nocardioides, Pseudomonas, Ralstonia, Flavobacterium, and Caulobacter previously not known to degrade polychlorophenols. In addition, six polychlorophenol-degrading sphingomonads were found.
Received: 27 September 1998 / Accepted: 21 December 1998 相似文献
4.
Karima Taher Sarah Graf Mohamed Moez Fakhfakh Halim B. H. Salah Amor Yahyaoui Salah Rezgui Bouzid Nasraoui Gerd Stammler 《Journal of Phytopathology》2014,162(7-8):442-448
Sensitivity of 159 isolates of Zymoseptoria tritici collected from durum wheat fields in Tunisia in 2012 was analysed towards pyraclostrobin, fluxapyroxad, epoxiconazole, metconazole, prochloraz and tebuconazole using microtiter tests. All isolates were found to be highly sensitive to pyraclostrobin with EC50 <0.01 mg/l with the exception of three isolates from the same field with higher EC50 values (>0.5 mg/l). These three isolates carried a mutation in the cytochrome b gene encoding the G143A substitution. This is the first report of quinone outside inhibitors (QoI) resistance in Z. tritici in Tunisia. Sensitivity towards r fluxapyroxad was in a narrow range with EC50 values ranging between 0.013 and 0.125 mg/l, which can serve as baseline sensitivity data for the future. Demethylation inhibitors sensitivity varied across a broad range with the data indicating a slight shift in sensitivity when compared to a previous study on the 2010 population. No highly sensitive strains were isolated from samples from fields, which had received three or four DMI applications. 相似文献
5.
The effect of five fungicides, benomyl (1 mg/l), dodine (50 mg/l), manzate (100 mg/l), cupric sulphate (200 mg/l) and thiabendazole
(4 mg/l) was tested under in␣vitro conditions on development of 15 isolates of fungi pathogenic for insects and␣other invertebrates
(Beauveria brongniartii, Culicinomyces clavisporus, Duddingtonia flagrans, Hirsutella thompsonii, two Metarhizium anisopliae, Nomuraea rileyi, two Isaria/Paecilomyces spp., and Sporothrix insectorum) and 13 isolates of contaminant fungi (five Aspergillus spp., Cladosporium cladosporioides, Cunninghamella echinulata, Fusarium roseum, Gliocladium sp., Mortierella isabellina, Mucor plumbeus, Rhizopus arrhizus and Trichothecium roseum) originating mostly from tree-hole breeding sites of mosquitoes. Most pathogenic and contaminant fungi had clear patterns
of susceptibility or resistance to tested concentration of the fungicide. Development of both pathogenic and contaminant fungi
on fungicide-supplemented medium varied among fungi and fungicides tested. Minimal inhibition of pathogenic fungi was found
for cupric sulphate, benomyl, dodine, thiabendazole < manzate. The highest inhibition of contaminants was obtained with thiabendazole > benomyl
and dodine > manzate and cupric sulphate. Thiabendazole was the most appropriate fungicide to isolate fungi pathogenic to
invertebrates from substrates with high water contents and rich in organic material. The results underline the importance
of adapting both a fungicide and its concentration for a selective medium for isolating specific target fungi and while selecting
against possible contaminants. 相似文献
6.
Shikha Kumari Pandey Sukalyan Chakraborty 《International journal of phytoremediation》2016,18(1):87-93
Three naturally growing plants Ipomoea carnea, Lantana camara, and Solanum surattense were found in fly ash dumpsite of Patratu thermal power station, Jharkhand, India. They were assessed for their metal uptake potential. The fly ash was slightly alkaline with very less nitrogen and organic carbon but enriched with phosphorus and heavy metals. Lantana camara and Ipomoea carnea showed good translocation from root to shoot for most of the metals except Mn and Pb. The order of metal accumulation in stem of both the plants were Fe(205mg/kg)>Mn(65mg/kg)>Cu(22.35mg/kg)>Pb(6.6mg/kg)>Cr(3.05mg/kg)>Ni(1 mg/kg)>Cd(0.5 mg/kg) and Fe(741 mg/kg)>Mn(154.05 mg/kg)>Cu(20.75 mg/kg)>Pb(6.75 mg/kg)>Ni(4.0 mg/kg)>Cr(3.3mg/kg)>Cd(0.05mg/kg), respectively. But Solanum surattense accumulated most of the metals in roots. The order was in the following order, Mn (382.2mg/kg) >Fe (264.1mg/kg) > Cu (25.35mg/kg) >Pb (5.95 mg/kg) > Ni (1.9 mg/kg) > Cr (1.8mg/kg) > Cd (0.55 mg/kg). The order of Bioconcentration factor (BCF) in root and shoot followed almost the same order as, Mn>Fe>Ni>Pb>Cu>Cr≈ Cd in all the three species. ANOVA showed significant variation in metal accumulation by root and stem between the species. Finally, it can be concluded that Solanum surattense can be used as phytostabilizer and other two species as phytoextractor of metal for fly ash dumpsite reclamation. 相似文献
7.
Leta S. Gumaelius L. Assefa F. Dalhammar G. 《World journal of microbiology & biotechnology》2004,20(4):405-411
In order to identify potential microorganisms with high denitrifying capacity from tannery wastewaters, 1000 pure cultures
of bacterial isolates from Modjo Tannery Pilot and Ethio-tannery wastewater treatment plants (WWTP), in Ethiopia, were investigated.
Twenty-eight isolates were selected as efficient denitrifiers. These were Gram-negative rods, oxidase and catalase positive
denitrifying organisms. The 28 denitrifying strains were further classified according to their biochemical fingerprints into
three different phylogenetic groups (BPT1, BPT2 and BPT3) and seven singles. Isolates B79T, B11, B12, B15, B28 and B38 belonging to the BPT3 cluster were found to be the most efficient denitrifying bacteria. All
phenotypic studies, including cellular fatty acid profiles, showed that the 6 BPT3 isolates were closely related to each other.
The 16S rRNA partial sequence analysis of type strain B79T(CCUG 45880) indicated a sequence similarity of 99% to Brachymonas denitrificans JCM9216 (D14320) in the β-subdivision of proteobacteria. Further studies of the effects of chromium III and sulphide on the six Brachymonas denitrificans strains indicated that denitrification by the isolates were inhibited 50% at concentrations of 54 and 96 mg/l, respectively.
The efficient isolates characterized in this study are of great value because of their excellent denitrifying properties and
relatively high tolerance to the concentrations of toxic compounds (70 mg chromium/l and 160 mg sulphide/l) prevailing in
tannery wastewaters. 相似文献
8.
To evaluate the in vitro efficacy of common antifungal drugs, as well as the interactions of caspofungin with voriconazole,
amphotericin B, or itraconazole against the pathogenic black yeast Exophiala dermatitidis from China, the minimal inhibitory concentrations (MICs) of terbinafine, voriconazole, itraconazole, amphotericin B, fluconazole,
and caspofungin against 16 strains of E. dermatitidis were determined by using CLSI broth microdilution method (M38-A2). The minimal fungicidal concentrations (MFCs) were also
determined. Additionally, the interactions of caspofungin with voriconazole, amphotericin B, itraconazole or fluconazole,
that of terbinafine with itraconazole, or that of fluconazole with amphotericin B were assessed by using the checkerboard
technique. The fractional inhibitory concentration index (FICI) was used to categorize drug interactions as following, synergy,
FICI ≤ 0.5; indifference, FICI > 0.5 and ≤4.0; or antagonism, FICI > 4.0. The MIC ranges of terbinafine, voriconazole, itraconazole,
amphotericin B, fluconazole, and caspofungin against E. dermatitidis were 0.06–0.125 mg/l, 0.25–1.0 mg/l, 1.0–2.0 mg/l, 1.0–2.0 mg/l, 16–64 mg/l, and 32–64 mg/l, respectively. The in vitro interactions
of caspofungin with voriconazole, amphotericin B, and itraconazole showed synergic effect against 10/16(62.5%), 15/16(93.75%),
and 16/16(100%) isolates, while that of caspofungin with fluconazole showed indifference. Besides, the interaction of terbinafine
with itraconazole as well as that of fluconazole with amphotericin B showed indifference. Terbinafine, voriconazole, itraconazole,
and amphotericin B have good activity against E. dermatitidis. The combinations of caspofungin with voriconazole, amphotericin B or itraconazole present synergic activity against E. dermatitidis. These results provide the basis for novel options in treating various E. dermatitidis infections. 相似文献
9.
Yu-Ji Lian Guang-Zhe Lin Xiao-Mei Zhao Hak-Tae Lim 《In vitro cellular & developmental biology. Plant》2011,47(2):289-296
Inter-specific somatic hybrids of leaf mustard (Brassica juncea) and broccoli (Brassica oleracea) were established to introduce cytoplasmic male sterility (CMS) and Verticillium dahliae Kleb. resistance from broccoli to leaf mustard. Protoplasts isolated from hypocotyls and cotyledons of inbred lines of leaf
mustard and broccoli were fused using 40% (w/v) polyethelene glycol and then cultured in modified k8p medium supplemented with 0.2 mg/l 2,4-dichlorophenoxi-acetic acid,
0.5 mg/l 6-benzyladenine (BA), 0.1 mg/l naphthaleneacetic acid (NAA), and 0.1 mg/l kinetin (Kin), and 0.4 M mannitol as osmoticum.
At the eight- to ten-cell stage, divided cells were transferred to Kao’s basal medium supplemented with 0.3 M sucrose as carbon
source and 0.1% agarose, 2 mg/l BA, 2 mg/l zeatin (ZEA), 1 mg/l NAA, and 0.5 mg/l Kin for callus proliferation. After 35 d,
when small calli reached 2–3 mm in diameter, calli were transferred to regeneration medium containing 5 mg/l ZEA and 2 mg/l
indole-3-acetic acid. The chromosome numbers of putative somatic hybrids varied from 46 to 54. A total of ten plants showed
a 0.5-kb, CMS-specific band, while two regenerated plants showed a missing band similar to that of leaf mustard by polymerase
chain reaction amplification using Ogura CMS-specific primers. Hybrid state was confirmed by random amplified polymorphic
DNA analysis. Regenerated plants had normal petals and stamens, but only two plants produced pollen and set seed. 相似文献
10.
F. A. LAWS DIANNE J. WALMSLEY-WOODWARD W. J. WHITTINGTON 《The Annals of applied biology》1982,100(2):253-262
The germination and colony growth of single-pustule Erysiphe graminis isolates tolerant and sensitive to tridemorph and ethirimol was studied on glass slides and on leaf segments sprayed with tridemorph or left untreated. In the absence of the fungicide, neither tridemorph- nor ethirimol-tolerant isolates differed from the sensitive in germination or colony growth. Germination percentages of all isolates were depressed by high temperature and low humidity, although some isolates grew well in less than optimum conditions. Differences between ethirimol- and tridemorph-tolerant and sensitive isolates for colony size on untreated plants of various cultivars reflected differences in virulence to the host rather than fungicide tolerance. The presence of tridemorph retarded the growth rate of colonies of tolerant and sensitive isolates, but the germination of tridemorph-tolerant isolates was greatly stimulated by low concentrations of tridemorph (50 mg/litre) and was less depressed than that of the sensitive isolates by high concentrations (200 mg/litre). 相似文献
11.
Serpentine soils of Andaman Islands, India characteristically contain high levels of nickel, cobalt and chromium and are colonized by indigenous nickel-hyperaccumulating plants. Attempts have been made to isolate and characterize nickel-resistant microorganisms from these hitherto unexplored naturally nickel-percolated soils. The majority of the nickel-resistant organisms showed a minimum inhibitory concentration (MIC) of Ni2+ ranging from 300 to 400 mg/l and about 3.4% of the total 89 isolates representing bacterial strains were able to grow at 400 mg/l Ni2+. The potent Ni2+-resistant strains AND305 and AND603 were tentatively identified as Pseudomonas spp. and strain AND408 as Bacillus sp. following detailed analysis of morphological and physio-biochemical characteristics. Growth kinetics of these Ni2+-resistant bacteria showed a prolonged lag phase in Ni2+-containing media, which extended with increasing nickel concentration. In addition to Ni2+, these isolates were also resistant to Co2+, Cd2+, Cr6+, Fe3+, Cu2+, Mg2+, Mn2+(50–200 mg/l) and Hg2+ (0.5–2.0 mg/l) and the multiple metal-resistance of the isolates were also associated with the resistance to antibiotics ampicillin, cycloserine and penicillin G. 相似文献
12.
X. Niu X. Li P. Veronese R. A. Bressan S. C. Weller P. M. Hasegawa 《Plant cell reports》2000,19(3):304-310
Substantial improvement in peppermint (Mentha x piperita L. var. Black Mitcham) genetic transformation has been achieved so that the frequency of transgenic plants regenerated (percent
of leaf explants that produced transformed plants) was 20-fold greater than with the original protocol. Essential modifications
were made to conditions for Agrobacterium tumefaciens co-cultivation that enhanced infection, and for selection of transformed cells and propagules during regeneration. A systematic
evaluation of co-cultivation parameters established that deletion of coconut water from the co-cultivation medium resulted
in substantially increased transient β-Glucuronidase (GUS) activity, in both the frequency of explants expressing gusA and the number of GUS foci per explant (>700 explants). Co-cultivation on a tobacco cell feeder layer also enhanced A. tumefaciens infection. Enhanced transformation efficiencies were further facilitated by increased selection pressure mediated by higher
concentrations of kanamycin in the medium during shoot induction, regeneration, and rooting: from 20 to 50 mg/l in shoot induction/regeneration
medium and from 15 to 30 mg/l in rooting medium. Raising the concentration of kanamycin in media substantially lowered the
number of "escapes" without significant reduction in plant regeneration. These modifications to the protocol yielded an average
transformation frequency of about 20% (>2000 explants) based on expression of GUS activity or the tobacco antifungal protein,
osmotin, in transgenic plants. Genetic transformation of peppermint has been enhanced to the extent that biotechnology is
a viable alternative to plant breeding and clonal selection for improvement of this crop.
Received: 7 December 1998 / Revision received: 27 April 1999 / Accepted: 14 May 1999 相似文献
13.
An efficient transformation protocol was developed for Eucalyptus tereticornis Sm. using cotyledon and hypocotyl explants. Precultured cotyledon and hypocotyl explants were cocultured with Agrobacterium tumefaciens strain LBA 4404 harboring the binary vector pBI121 containing the uidA and neomycin phosphotransferase II genes for 2 d and transferred to selective regeneration medium containing 0.5 mg/l 6-benzylaminopurine
(BAP), 0.1 mg/l naphthalene acetic acid, 40 mg/l kanamycin, and 300 mg/l cefotaxime. After two passages in the selective regeneration
medium, the putatively transformed regenerants were transferred to Murashige and Skoog (MS) liquid medium containing 0.5 mg/l
BAP and 40 mg/l kanamycin on paper bridges for further development and elongation. The elongated kanamycin-resistant shoots
were subsequently rooted on the MS medium supplemented with 1.0 mg/l indole-3-butyric acid and 40 mg/l kanamycin. A strong
β-glucuronidase activity was detected in the transformed plants by histochemical assay. Integration of T-DNA into the nuclear
genome of transgenic plants was confirmed by polymerase chain reaction and southern hybridization. This protocol allows effective
transformation and direct regeneration of E. tereticornis Sm. 相似文献
14.
Isolation and Characterization of Chromium(VI)-Reducing Bacteria from Tannery Effluents 总被引:3,自引:0,他引:3
Ilias M Rafiqullah IM Debnath BC Mannan KS Mozammel Hoq M 《Indian journal of microbiology》2011,51(1):76-81
Two chromium-resistant bacteria (IFR-2 and IFR-3) capable of reducing/transforming Cr(VI) to Cr(III) were isolated from tannery
effluents. Isolates IFR-2 and IFR-3 were identified as Staphylococcus aureus and Pediococcus pentosaceus respectively by 16S rRNA gene sequence analyses. Both isolates can grow well on 2,000 mg/l Cr(VI) (as K2Cr2O7) in Luria-Bertani (LB) medium. Reduction of Cr(VI) was found to be growth-associated in both isolates and IFR-2 and IFR-3
reduced 20 mg/l Cr(VI) completely in 6 and 24 h respectively. The Cr(VI) reduction due to chromate reductase activity was
detected in the culture supernatant and cell lysate but not at all in the cell extract supernatant of both isolates. Whole
cells of IFR-2 and IFR-3 converted 24 and 30% of the initial Cr(VI) concentration (1 mg/l) in 45 min respectively at 37°C.
NiCl2 stimulated the growth of IFR-2 whereas HgCl2 and CdCl2 significantly inhibited the growth of both isolates. Optimum temperature and pH for growth of and Cr(VI) reduction by both
isolates were found to be between 35 and 40°C and pH 7.0 to 8.0. The two bacterial isolates can be good candidates for detoxification
of Cr(VI) in industrial effluents. 相似文献
15.
Severe growth abnormalities, including leaf yellowing, sprout proliferation and flower virescence and phyllody, were found on Brassica rapa subsp. pekinensis plants in Poland. The presence of phytoplasma in naturally infected plants was demonstrated by polymerase chain reaction assay employing phytoplasma universal P1/P7 followed by R16F2n/R16R2 primer pairs. The detected phytoplasma was identified using restriction fragment length polymorphism analysis (RFLP) of the 16S rRNA gene fragment with AluI, HhaI, MseI and RsaI endonucleases. After enzymatic digestion, all tested samples showed restriction pattern similar to that of ‘Candidatus phytoplasma asteris’. Nested PCR‐amplified products, obtained with primers R16F2n/R16R2, were sequenced. Sequences of the 16S rDNA gene fragment of analysed phytoplasma isolates were nearly identical. They revealed high nucleotide sequence identity (>98%) with corresponding sequences of other phytoplasma isolates from subgroup 16SrI‐B, and they were classified as members of ‘Candidatus phytoplasma asteris’. This is the first report of the natural occurrence of phytoplasma‐associated disease in plants of Chinese cabbage. 相似文献
16.
A resveratrol synthase gene was cloned from the peanut plant (Arachis hypogaea) by RT-PCR and was transformed into purple sweet potato (Ipomoea batatas) by Agrobacterium-mediated transformation. Stem sections were infected with bacterial solution of OD600 = 0.4 for 20 min and then cocultured for 2 days. Infected explants were cultured on MS media containing 50 mg/l kanamycin,
0.02 mg/l NAA and 1 mg/l 6-BA for bud induction or containing 75 mg/l kanamycin, 1.0 mg/l NAA and 0.1 mg/l 6-BA for root formation.
The bud and root induction rates were 37.5 and 25.0%, respectively. 105 regenerated plants were obtained, with 11 positive
plants by PCR and Southern blotting analyses. A high level of resveratrol glucoside (340 μg/g dry weight), but no resveratrol,
was detected in the transformed plants by HPLC. This study also provides a stable genetic transformation and plant regeneration
method for metabolic modification of purple sweet potato. 相似文献
17.
Mitra Ebrahimi Ali Akbar Safari Sinegani Nasser Aliasgharzad 《Geomicrobiology journal》2013,30(10):873-880
AbstractAssessing the amount of released K from minerals in bacterial liquid culture is the main process for screening and isolation of efficient potassium releasing bacteria (KRB). This study was aimed to determine the amount of released K in solution phase or supernatant (SK) as well as microbial biomass K (MBK). Therefore, 20 different bacterial isolates belonging to the 10 bacterial genera (Beijerinckia, Klebsiella, Azotobacter, Pseudomonas, Agrobacterium, Rhizobium, Sphingomonas, Citrobacter, Microbacterium, and Achromobacter) were individually used to inoculate Aleksandrov medium in presence of biotite or muscovite. Our results from in-vitro experiments revealed that the MBK (K in pellet) is more important than in SK. Although some genera such as Azotobacter and Citrobacter released more SK (16?mg/l from biotite and 12.77?mg/l from muscovite, respectively), the Klebsiella isolates with the highest MBK could release an average of 90?mg/l total K. This study indicated that the assimilated K in microbial cells is the main part of K dissolution from minerals. Due to the fast turnover of nutrients in bacterial biomass, it can be concluded that both SK and MBK could be available for plants. It seems that the finding of this research should be considered in the isolation of KRB.Highlights
This study reports, assessment of soluble and biomass K in the culture medium is a reliable tool for estimation of K releasing efficiency of bacteria
Our results from in vitro experiments revealed that the assimilated K in microbial cells is the main part of K dissolved from minerals.
Although some genera such as Azotobacter released more K in solution phase, the Klebsiella isolates with the highest biomass K could release more total K
18.
Antibacterial activities of essential oils from eight Greek aromatic plants against clinical isolates of Staphylococcus aureus 总被引:1,自引:0,他引:1
Alexopoulos A Kimbaris AC Plessas S Mantzourani I Theodoridou I Stavropoulou E Polissiou MG Bezirtzoglou E 《Anaerobe》2011,17(6):399-402
Aromatic plants have been used widely to extend the shelf life of foods but at the same time research is undergoes for their properties as antibacterial agents in clinical use. Although there are promising results for the antimicrobial properties of various essential oils against environmental or food-isolated strains of Staphylococcus aureus, limited work has been done concerning these properties against clinical isolates of this pathogen. S. aureus is responsible for an increase number of nosocomial infections and at the same time exhibits increased resistance to synthetic agents.In this study, essential oils from eight aromatic plants common in Greece were isolated by hydrodistillation, analyzed by gas chromatography (GC) and GC/mass spectrometry (GC/MS) for their chemical components and tested for their antimicrobial activities against 24 clinical isolates of S. aureus. The methods used were disk diffusion and broth dilution in order to determine the Minimum Inhibitory Concentration (MIC).Our results showed that essential oils from Origanum vulgare and Origanum dictamnus were active against S. aureus when tested by disk diffusion, but exhibited increased MIC values (>256 mg/L) with the dilution method. In contrast, the reference strain NCTC 6571 showed to be extremely sensitive in most of the oils tested (MICs 0.25−32.0 mg/L) and resistant only to the essential oil from Ocimum basilicum. Therefore, there is no evidence of a potential clinical use for those essential oils and further research is needed in order to determine if they could substitute efficiently synthetic antibiotics or, perhaps be used in combination. 相似文献
19.
Mingjia Yang Xiangming Xie Caixia Zheng Fangqiu Zhang Xiaoqing He Zhiru Li 《Plant Cell, Tissue and Organ Culture》2008,95(2):141-147
A protocol was developed for Agroacterium-mediated genetic transformation of Acacia crassicarpa via organogenesis by using in vitro phyllode (leaf) as the explant. Phyllode (leaf) explants were co-cultured with Agrobacterium tumefaciens strain LBA4404 harbouring binary vector pBI101 (harboring antisense Pt4CL1 with respect to the Pt4CL1P promoter). The selection for transgenic shoots was performed through two consecutive steps on
Murashige and Skoog (MS) medium supplemented with different concentrations of plant growth regulators and antibiotics in the
following order: 0.5 mg/l thidiazuron (TDZ), 0.5 mg/l α-naphthaleneacetic acid (NAA), 300 mg/l carbenicillin (Car) and 20 mg/l
kanamycin (Km) for 10 days; 0.1 mg/l TDZ, 200 mg/l Car and 20 mg/l Km for 60 days; 0.5 mg/l indole-3-butyric acid (IBA), 100 mg/l
Car and 20 mg/l Km 50 days. 21.7% of nodules produced multiple adventitious shoot buds, of which 27.7% survived in initial
selection. The shoot buds were subjected to repeated selection on MS medium supplemented with 0.1 mg/l TDZ, 200 mg/l Car and
20 mg/l Km for 60 days. Transgenic plants were obtained after rooting on half-strength MS medium supplemented with 0.5 mg/l
IBA, 100 mg/l Car 20 mg/l Km 50 days. Genomic PCR analysis confirmed the incorporation of the antisense Pt4CL1 with respect to the Pt4CL1P promoter fragment into the host genome. 相似文献
20.
Almut Gerhardt 《人类与生态风险评估》2009,15(1):27-40
A new automated online toxicity test for screening of short-term effects of chemicals is presented using the freshwater oligochaete Tubifex tubifex in the Multispecies Freshwater Biomonitor? (MFB). Survival and locomotory behavior of the worms were observed during 24 h of exposure to metals (Cd, Cu, Ni), pesticides (Imidacloprid), and pharmaceuticals (Ivermectin). The LC50 values revealed increasing toxicity in the following order: Ni (> 100 mg/l) < Cu (15.2 mg/l) < Cd (4.9 mg/l) < Ivermectin (1.8 mg/l) < Imidacloprid (0.3 mg/l). The EC50 for locomotion showed a similar order of increasing toxicity: Ni (86 mg/l) < Cu (3.8 mg/l) < Ivermectin (2.0 mg/l) < Cd (1.1 mg/l) < Imidacloprid (0.09 mg/l). Toxicity was dependent on both concentration and exposure time. This could be demonstrated in 3d response models and proven in the statistical analysis showing a significant interaction term (C × T) for the experiments with Cu and Ni. T. tubifex proved to be very tolerant, but even then behavioral responses were more sensitive than mortality for Cu, Cd, and Imidacloprid. 相似文献