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1.
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   

2.

Dibenzocyclooctadiene lignans are a specific group of secondary metabolites that occur solely in Schisandra chinensis. The aim of the presented work was to boost the accumulation of lignans in the agitated microshoot cultures of S. chinensis, using different elicitation schemes. The experiments included testing of various concentrations and supplementation times of cadmium chloride (CdCl2), chitosan (Ch), yeast extract (YeE), methyl jasmonate (MeJa), and permeabilizing agent—dimethylsulfoxide (DMSO). After 30 days, the microshoots were harvested and evaluated for growth parameters and lignan content by LC-DAD method. The analyses showed enhanced production of lignans in the elicited S. chinensis microshoots, whereas the respective media samples contained only trace amounts of the examined compounds (< 5 mg/l). Elicitation with CdCl2 caused up to 2-fold increase in the total lignan content (max. ca. 730 mg/100 g DW after the addition of 1000 μM CdCl2 on the tenth day). Experiments with chitosan resulted in up to 1.35-fold increase in lignan concentration (max. ca. 500 mg/100 g DW) after the supplementation with 50 mg/l on the first day and 200 mg/l on the tenth day. High improvement of lignan production was also recorded after YeE elicitation. After the elicitation with 5000 mg/l of YeE on the first day of the growth period, and with 1000 and 3000 mg/l on the 20th day, the lignan production increased to the same degree—about 1.8-fold. The supplementation with 1000 mg/l YeE on the 20th day of the growth cycle was chosen as the optimal elicitation scheme, for the microshoot cultures maintained in Plantform temporary immersion system—the total content of the estimated lignans was equal to 831.6 mg/100 g DW.

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3.
Pseudomonas sp. strain IST103 obtained from a stable consortium was capable of degrading pentachlorophenol (PCP) as sole carbon and energy source. The PCP-degrading potentiality of the strain was determined by growth of bacteria in culture medium, utilization of PCP by high performance liquid chromatography (HPLC), chloride release and ring cleavage. The strain was applied in two set of soil microcosms containing 20 and 40% moisture, each having different concentrations, 0, 10, 100, 500, and 1000 mg/l, of PCP. The result showed significant utilization of PCP (77% in 45 days) and higher growth of bacterial strain when PCP was applied in 100 mg/l concentration at 40% moisture. Inhibitory effects on the growth of bacterial strain were seen in 500 and 1000 mg/l concentration.  相似文献   

4.
To evaluate the role of exogenous application of a phytochelating agent glutathione in increasing resistance against different heavy metals stress, nodal explants excised from 28-day-old in vitro seedlings of Spilanthes calva L. were cultured on Murashige and Skoog’s medium supplemented with 10 μM benzyl adenine and five different concentrations (1, 5, 50, 100, or 200 mg/l) of four heavy metals: As2O3, CuSO4, ZnSO4, or Pb(NO3)2. Data were recorded for percent survival, shoot number, and shoot length after 28 d of heavy metal treatment. All four heavy metals severely inhibited growth and morphogenesis. Pb proved most inhibitory whereas Zn was least effective. Pb was further selected to study the reversal effect of glutathione on morphogenesis. The addition of different concentrations (1, 5, 10, or 25 mg/l) of glutathione to media containing the Pb resulted in a significant improvement in almost all growth parameters. Inclusion of glutathione at 10 mg/l was optimum for maximum reversal of the negative effects of heavy metals on morphogenesis.  相似文献   

5.
Fumigation with methyl bromide (MeBr) at a concentration of 120 mg/1 maintained for 4 h at 25°C caused 100% mortality of spores of Aspergillus ochraceus, A. flavus, Penicillium citrinum, P. chrysogenum and P. cyclopium. However, 40% of an A. niger spore population retained its viability after this treatment. Increasing the duration of fumigation to 24 h at a concentration of 40 mg/1 MeBr caused 100% spore mortality of all fungi tested. Total growth inhibition of 24 h-old mycelia was achieved with 40 mg/1 for 24 h or 120 mg/1 for 4 h. These concentrations for the same period of exposure were not inhibitory for 7-day-old mycelia of any of the fungi tested. In A. niger-inoculated wheat grains fumigated with 100 mg/1 MeBr for 24 h, 20% yielded fungal contaminants after 16 days of storage and 100% after 29 days. There was a marked drop in the percent germination of the grains after fumigation, whereas the free fatty acids level was higher than in unfumigated grain. The results of the in vivo study suggest that MeBr given at a commercial dosage for 24 h is not only ineffective in destroying the internal inocula of wheat grains but also enables their subsequent development by weakening the resistance of grains to fungal attack.  相似文献   

6.
In order to evaluate the effects of immersion marking with calcein (CAL) and alizarin red S (ARS) on growth and mortality of juvenile bighead carp Aristichthys nobilis, and assess mark quality in otoliths, scales, and fin rays, CAL from 50 to 200 mg L?1 and ARS from 150 to 300 mg L?1 concentrations were used. With the exception of non‐lateral line scales from 50 mg L?1 CAL treatments, immersion for 24 h produced detectable marks in sagittae, lateral line and non‐lateral line scales, and fin rays (dorsal, pectoral, ventral, anal, and caudal) at 100 days post‐marking. Detectable fluorescent marks in sagittae were readily observed at concentrations of 150–200 mg L?1 CAL or 150–300 mg L?1 ARS. Marks were poorly visible in all non‐lateral line scales from both CAL‐ and ARS‐treated groups. Fluorescent marks were readily detected in lateral line scales at 100–200 mg L?1 CAL or 150–300 mg L?1 ARS, and in fin rays at 150–200 mg L?1 CAL or 150–300 mg L?1 ARS. In particular, optimal marks were observed at the highest concentrations investigated in sagittae (300 mg L?1 ARS), lateral line scales (150–200 mg L?1 CAL or 250–300 mg L?1 ARS), and fin rays (200 mg L?1 CAL or 250–300 mg L?1 ARS). However, fluorescent marks visible to the naked eye were not produced by any of the CAL or ARS treatments in sagittae, scales, or fin rays during this experiment. In addition, there was no significant difference on survival and growth of marked fish compared to controls throughout the experiment (P > 0.05).  相似文献   

7.
Microbial contamination is a serious problem in temporary immersion systems (TIS) during commercial micropropagation. The use of adequate doses of silver nanoparticles (AgNPs), formulated as Argovit?, is an alternative to reduce the contamination indices and promote development in plants. The aim of this study was to evaluate the antimicrobial and hormetic effects of Argovit on in vitro regeneration of vanilla (Vanilla planifolia) using a TIS. In vitro regenerated shoots were grown in Murashige and Skoog (MS) liquid medium with Argovit at five different concentrations (0, 25, 50, 100 and 200 mg/l) using a temporary immersion bioreactor system (RITA®). At 30 days of culture, contamination percentage was evaluated and shoot regeneration and length were used to determine the hormetic response. Analysis of macro and micronutrient contents was performed. In addition, the effect of Argovit on total phenolic content (TPC), reactive oxygen species (ROS) production, antioxidant capacity (ORAC) and lipid peroxidation (LP-MDA) was determined. Results showed that bacterial contamination was reduced at 50, 100 and 200 mg/l of Argovit. Growth stimulation was observed at 25 and 50 mg/l of Argovit, while significant inhibition was detected at 100 and 200 mg/l of Argovit. Mineral nutrient analysis revealed changes in macro and micronutrient concentrations exerted by Argovit. Moreover, the presence of Argovit induced the production of ROS and increased total phenolic content, antioxidant capacity and lipid peroxidation with a dose-dependent effect. Results suggested that the production of ROS and mineral nutrition are key mechanisms of AgNPs-induced hormesis for vanilla. Therefore, the addition of 50 mg/l of Argovit in the culture media had an antimicrobial and hormetic effect. Use of Argovit could be an efficient strategy for commercial micropropagation of vanilla and other species.  相似文献   

8.
Malonate exerted a stronger inhibitory effect on brefeldin A production than on mycelia growth in cultures ofCurvularia lunata especially at inhibitory levels of 100 to 200 mm. The extent of 200 mm malonate inhibition of growth and brefeldin A production was greater in cultures treated with malonate prior to inoculation than those treated following 5 days after inoculation. Maleate at levels of 40 to 220 mm activated brefeldin A formation in cultures though exerting variable effects on mycelia growth.  相似文献   

9.
The synthetic mustered flavouring essential oil, allyl isothiocyanate (AITC), was evaluated for its effect on suppression of Rhizoctonia solani growth in vitro, and in field soils for reducing inoculum density, saprophytic substrate colonization and seedling damping off and blight using snap bean and cabbage as indicator plants. In vitro growth was completely inhibited at the concentration of 50 μl/l. Inoculum density and saprophytic substrate colonization by the fungus in soil were not affected by AITC concentrations of 50 or 75 μl/kg soil. The inoculum density estimation by the use of soil‐drop technique created an artefact leading to an erroneous conclusion that the fungus was eradicated from soil within 1–3 days after AITC treatment at 150 or 200 μl/kg soil. The saprophytic substrate colonization showed that although the activity of R. solani was greatly reduced, the fungus still colonized 45% of the substrate units at these concentrations, and up to 100% at lower concentrations within 1 day after treatment. At higher concentrations the recovery rate from the substrates gradually declined over time to <6%. Drenching R. solani infested sandy‐loam or silty‐clay‐loam soil with water containing the emulsified AITC to provide 150 or 200 μl/l soil, a few days prior to planting, gave over 90% disease control in snap bean and cabbage, with no apparent phytotoxic effect. The effect of AITC was not influenced by the physical soil texture. AITC appears to have a good potential to replace methyl bromide fumigation of the substrate used for transplant production.  相似文献   

10.
Anker's medium with glucose and Thornton's medium were most suitable for growing Enterobacter aerogenes and Bacillus subtilis respectively, antagonists of P. cactorum, the causal agent of apple crown rot. Calcium nitrate was thebest source of nitrogen for growing cultures of E. aerogenes and B. subtilis. E. aerogenes produced the maximum amount of antifungal substance at 200 and 400 mg/l of nitrogen in the medium. Phosphate supplied either in the potassium or calcium form did not change the growth of either antagonist. An addition of 200 mg/l of N and 400 mg/l of P significantly enhanced the production of antifungal substance by E. aerogenes on Anker's medium with glucose. Thornton's medium supplemented with 200 mg/l of N and 100 mg/l of P produced the maximum amount of antifungal substance from B. subtilis. Generally, soil extracts without enrichment did not support the growth of either antagonist; E. aerogenes required at least 400 mg/lof, both N and P while B. subtilis required 200 mg/l of N and 800 mg/l of P for the maximum production of antifungal substance. When ammonium phosphate was added to soil extracts, only a small amount of antifungal substance was produced by E. aerogenes and none by B. subtilis. These results indicate that E. aerogenes and B. subtilis need N and P fertilization of the sterilized soil for the maximum production of the antifungal substance that inhibits the growth of P. cactorum.  相似文献   

11.
A methanol extract of leaves of oat seedlings grown in sand cultures in the dark contained a compound which inhibited the growth of Ophiobolus graminis. The inhibitory factor was isolated and proved to be present in the plant as methoxyhydroquinone glucoside. The glucoside was readily hydrolysed to the corresponding aglucone. The methoxyhydroquinone, or possibly its oxydation product, methoxy-P-benzoquinone, was inhibitory to both Ophiobolus graminis var. graminis and Ophiobolus graminis var. avenae, whereas Fusarmm oxysporum var. lycopcrsici was not affected. Synthetic methoxyhydroquinone at 80 mg/l gave a 100% inhibition of Ophiobolus graminis var. graminis. After being exposed to 80 mg/l of the inhibitor for 24 h the mycelium was unable to initiate growth when transferred to a fresh nutrient solution. Only extracts from young leaves showed inhibitory activity, extracts from mature leaves giving no inhibition. The hydroquinone, or its glucoside, was not detected in roots of young seedlings, where avenacin was the only antifungal compound present.  相似文献   

12.
This study examined the effects of a range of black, grey and white substrata on the growth and attachment strength of Ulva sporelings on glass and polydimethylsiloxane (Silastic®-T2) surfaces. The rate of development of sporelings was strongly influenced by the colour of the substratum on which they grew. On black backgrounds, sporelings grew slowly and germination was delayed. Laboratory screening methods for antifouling and fouling-release coatings that rely on the growth of Ulva sporelings can be compromised if samples are of different colours. Hydrodynamic removal of sporelings from coatings may also be affected by substratum colour, since smaller plants generate lower hydrodynamic forces making them more difficult to remove.  相似文献   

13.
During the anaerobic biodegradation of effluent from a dimethyl terephthalate (DMT) manufacturing plant, reduction in chemical oxygen demand (COD) degradation and biogas formation was observed after the waste-water concentration exceeded 25% of added feed COD. This condition reverted back to normal after 25–30 days when the DMT waste-water concentration in the feed was brought down to a non-toxic level. However, the above effects were observed only after the concentration of DMT waste-water reached more than 75% of added feed COD when biomass support particles (BSP) were augmented to the system. In the BSP system, a biomass concentration of up to 7000 mg/l was retained and the sludge retention time increased to > 200 days compared to 2200 mg/l and 8–10 days, respectively, in the system without BSP (control). Formaldehyde in the waste-water was found to be responsible for the observed toxicity. The BSP system was found to resist formaldehyde toxicity of up to 375 mg/l as against 125 mg/l in the control system. Moreover, the BSP system recovered from the toxicity much faster (15 days) than the control (25–30 days). The advantages of the BSP system in anaerobic treatment of DMT waste-water are discussed. Correspondence to: C. Ramakrishna  相似文献   

14.
Macrophomina phaseolina is a causal agent for charcoal rot and cause economic damage in plants. In recent years, the great tendency for the use of biological substances to control of pests, weeds and the pathogens has been created. In this study, antifungal effects of concentrations 30, 60 and 120?μl/100?ml of essential oil of Eucalyptus sp. and Zataria multiflora were evaluated on the growth of M. phaseolina in vitro condition. The experiment was conducted on phactorial basis of completely randomised design with four replications. According to the results, a significant difference between inhibitory percentage of essential oils and different concentrations of essential oils on fungal colony growth has been observed (p?≤?0.01). Highest inhibitory percentage was related to the concentration of 120?μl/100?ml of Z. multiflora with 58.16% inhibition.  相似文献   

15.
该研究以掌叶大黄、唐古特大黄和药用大黄种子为材料,采用双层滤纸培养法,设置系列浓度NaCl (0、100、150、200、250 mmol/L) 胁迫试验,以及系列浓度水杨酸(SA)溶液(0、50、100、150、200、250 mg/L)拌种和浸种后盐胁迫实验,测定3种大黄种子萌发及幼苗生长指标,揭示外源水杨酸对盐胁迫下大黄种子萌发及幼苗生长的影响。结果显示:(1)随NaCl浓度增大3种大黄种子的发芽率均呈直线下降趋势,且子叶、胚轴、根和苗等生长均受到强烈抑制。(2)在拌种条件下, 200 mmol/L NaCl胁迫下掌叶大黄苗长在200 mg/L SA处理下受到显著促进; 200 mmol/L NaCl浓度盐胁迫下唐古特大黄种子发芽率在250 mg/L SA处理下受到显著抑制;100 mmol/L NaCl胁迫下药用大黄种子发芽势在200 mg/L SA处理下受到显著抑制,其发芽率在150 mg/L SA处理下得到显著抑制,其苗长在250 mg/L SA处理下受到显著抑制。(3)在浸种条件下, 200 mmol/L NaCl胁迫下掌叶大黄种子发芽率在50 mg/L SA处理下显著提高,其幼苗根长和苗长的生长在250 mg/L SA处理受到显著促进;200 mmol/L NaCl胁迫下唐古特大黄种子的发芽势在200 mg/L SA处理下得到显著促进,其幼苗根和苗的生长在50 mg/L SA处理下得到显著促进;100 mmol/L NaCl 胁迫下药用大黄根和苗的生长在100 mg/L SA处理下均得到显著促进。研究表明,3种大黄种子和幼苗对盐胁迫的响应趋势一致,但对不同浓度SA拌种和浸种的响应有较大差异。  相似文献   

16.
Polytrichum commune spores contained 5.61 ± 0.52 mg steryl and wax esters, including volatile compounds, per 100 mg dry weight of spores. Volatile compounds were not found in 3-h-old sporelings. The content of the steryl and wax ester fraction, excluding the volatile compounds, is slightly increased during the first 6 h of germination. Thereafter, the content is decreased throughout the germination. Thus, 3-day-old sporelings contained 0.52 ± 0.05 mg steryl and wax esters per 100 mg dry weight of spores. In connection with protonema growth, steryl and wax esters were produced, and the 7-day-old cultures contained 5.09 ± 0.37 mg steryl and wax esters per 100 mg dry weight of spores. The main fatty acids of the steryl and wax ester fraction of dry spores and germinating spores as well as of protonemata were palmitic, oleic, linoleic and linolenic acids. Polyunsaturated C 20 acids were present only in trace or small amounts. Phytanic and phytenic acids were found in small amounts in dry spores, in 3- to 72-h-old sporelings, and in protonemata.  相似文献   

17.
One-month-old fruits of Acer ginnala with winged pericarp attached gave 44% germination and this was not increased by cold treatment at 4°C for 0, 10, 20, or 30 days, gibberellic acid treatment at 0, 1, 10, 100 or 1000 mg litre-1, or ethephon treatment at 0, 2, 20, 200 or 2000 mg litre-1. After 6 months of storage at 20–25 °C, germination of untreated fruits fell to 5% but could be restored to that of 1-month-old fruits by incubation at 4 °C for 30 days. After 9 months storage, no germination occurred in untreated fruits. Cold treatment (30 days at 4 °C partially restored germination (26%). Treatment with either gibberellic acid (1000 mg litre-1) and 30 days at 4 °C (40%) or ethephon (100 mg litre-] and 30 days at 4 °C improved germination (69%). The combination of all three treatments, i.e. 100 mg litre-1 gibberellic acid, 100 mg litre-1 ethephon and 30 days at 4 °C, optimised germination (86%). Thus, dormancy of A. ginnala developed during storage but could be reversed by a combination of treatment with low temperature and growth regulators. The highest germination (86%) was achieved after low temperature and growth regulator treatment of stored fruit.  相似文献   

18.
The effects of timentin on shoot regeneration of tobacco (Nicotiana tabaccum) and Siberian elm (Ulmus pumila L.) and its use for the suppression of Agrobacterium tumefaciens in Agrobacterium-mediated genetic transformation were determined. Timentin is a mixture of ticarcillin and clavulanic acid, and at concentrations of 200–500 mg/l with ratios of ticarcillin:clavulanic acid of 50:1 and 100:1, it had little effect on shoot regeneration of tobacco or Siberian elm. Timentin was as effective in suppressing A. tumefaciens as carbenicillin and cefatoxime at concentrations commonly used in transformation. The disarmed A. tumefaciens strain LBA4404 in infected tobacco leaf tissues was visually undetectable after three subcultures on medium with 500 mg/l of timentin and 250 mg/l carbenicillin. Timentin was stable in solid agar medium and remained effective for at least 70 days, but was unstable when stored as a mixed stock solution or as separate ticarcillin and clavulanic acid stock solutions at –20°C or –80°C freezer for 4 weeks. Timentin may be an alternative antibiotic for the effective suppression of A. tumefaciens in genetic transformation. Received: 8 September 1997 / Revision received: 19 November 1997 / Accepted: 2 December 1997  相似文献   

19.
Flavonoids are agents with strong antioxidant properties and ameliorate many diseases associated with oxidative stress. Leaves of Casimiroa sapota were investigated for components and antioxidant/anti‐inflammatory activities against lead acetate ((AcO)2Pb) induced hepatotoxicity in rats. Three groups of male albino rats were administrated orally with vehicle or C. sapota (100 and 200 mg/kg b.w/day) for 28 days; other group was injected with sub‐acute dose (100 mg/kg b.w/day) of (AcO)2Pb. Three protective groups were injected with (AcO)2Pb (100 mg/kg b.w/day) for 7 days at day 22 after treatment with either C. sapota (100 or 200 mg/kg b.w/day) or silymarin (SILY) for 28 days. We isolated and identified, from C. sapota, a new compound for the 1st time in nature; 5,6,2′,3′‐tetramethoxyflavone in addition to the rare compound 5,6,3′‐trimethoxyflavone (second report of isolation from nature) and the known compound 5,6,2′,3′,4′‐pentamethoxyflavone. There is an improvement in all hemato‐biochemical parameters, antioxidant defense system and anti‐inflammatory cytokines of protective groups, which received C. sapota in dose dependent manner. The percentage of changes in all parameters measured in (AcO)2Pb groups that received vehicle, CS100, CS200 or SILY were 109.2, 37.3, 12.5%, and 1.2% compared with the healthy control group. The C. sapota groups confer a better antioxidant activity by preventing oxidative stress and inflammation in (AcO)2Pb treated rats. The compounds isolated are responsible at least in part for the observed protective effects.  相似文献   

20.
A simple and efficient protocol for plant regeneration from mesophyll protoplasts ofNierembergia repens is described. The protoplasts divided in modified half-strength MS (/12 MS) medium containing benzylaminopurine (BA) and a-naphthaleneacetic acid (NAA) and formed visible colonies after 2 weeks which produced single adventitious shoots 4 weeks later. Plating efficiency (11.2%), percent colony formation (0.84%), and the number of shoot-forming colonies (368/dish) were highest in /12 MS containing 0.1 mg/l BA and 0.05 mg/l NAA. However, the percentage of colonies with shoot formation was highest (31.8%) in /12 containing 0.05 mg/l BA and 0.01 mg/l NAA. Almost all of the remaining colonies (97.5%) also regenerated shoots upon transfer onto MS medium containing 0.05 mg/l BA. The shoots with 2–3 leaves readily rooted 3–5 days after insertion in /12MS lacking plant growth regulators. Regenerated plantlets were easily established in soil 50 days after protoplast isolation. All the regenerants were normal and possessed diploid chromosome numbers.Abbreviations BA Benzylaminopurine - FDA fluorescein diacetate - MES 2-(Morpholino)ethanesulfonic acid - MS Murashige and Skoog (1962) medium - /12MS half strength MS - NAA -naphthaleneacetic acid - PGR plant growth regulator  相似文献   

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