In situ regeneration of rice (Oryza sativa L.) callus immobilized in polyurethane foam

An in situ regeneration system for rice calli comprised of a callus growth stage and two regeneration stages was developed. After the first stage of regeneration, the medium is changed and the calli are immobilized in polyurethane foam supports, in each of which 3-5 regenerated plantlets develop from the immobilized calli during the second stage. While no significant change in callus size was observed during the first stage of regeneration, in the second stage callus enlargement and shoot regeneration predominated. In the light of these findings, calli were immobilized in the second stage after medium exchange. The use of 10-mm support cubes with an average pore size of 3.6 mm resulted in the most efficient immobilization and in situ regeneration. Medium exchange after 15 d gave the largest number of support cubes with shoots. When rice calli were cultivated in support cubes placed in 60 ml second-stage medium in a 500-ml flask, the immobilization ratio was 83%, and 82% of the support cubes contained 3-5 regenerated plantlets after 25 d. The shoot lengths of the regenerated plantlets obtained from the in situ regeneration culture were longer than those from a suspension culture. When support cubes with 3-5 regenerated plantlets were transferred from the flask to 1 4 MS solid medium supplemented with 10 g/l sorbitol and 5 g/l sucrose, the regenerated plantlets developed quickly into plants with a length above 10 cm after 10 d.     

基因工程方法抗甜菜丛根病病毒育种的研究：（Ⅰ）甜菜坏死黄脉病毒外 …

采用含有甜菜坏互黄脉病毒外壳蛋白（ＢＮＹＶＶ ＣＰ）基因的农杆菌，分别以不同甜菜品系的叶柄、下胚轴及子叶为外植体材料进行基因转化研究。含有ＢＮＹＶＶ ＣＰ基因和卡那抗性筛选基因的农杆菌与甜菜组织不同外植体共培养后，经过诱导分化培养，在含有卡那霉素的培养基上，从叶柄及下胚轴分别直接诱导出抗卡那霉素再生芽，而从子叶上只诱导出紧密型绿色愈伤组织，未分化出不定芽。从叶柄及下胚轴诱导两生芽的诱导培养基分别为     

培养条件对紫苏下胚轴外植体再生的影响

以紫苏下胚轴为材料,研究紫苏外植体芽再生的影响因素。结果表明：苗龄、黑暗时间、激素浓度及配比对紫苏芽再生均有较大影响。取13d苗龄的下胚轴先在分化培养基（MS＋3.0mg/L BA＋0.3mg/L NAA）黑暗预培养8d后转为14h/d光照条件培养可获得较高的再生频率。诱导芽苗生根最佳培养基为1/2MS＋1.0mg/L BA＋0.3mg/L IAA。     

An Efficient Regeneration System and Optimization of the Transformation from the Cotyledonary Node of Jute (Corchorus capsularis L.)

The purpose of this study was to use cotyledonary nodes as explants to establish an efficient regeneration protocol for jute (Corchorus capsularis L.) on Murashige and Skoog (MS) basal medium. Research into the different growth regulators using the orthogonal design L16 (4⁵) revealed that the best shoot induction medium is MS medium containing 8% (w/v) agar and 3% (w/v) sucrose supplemented with 1.0 mg/L 6BA and 0.25 mg/L NAA. The average number of shoots per explant and the explant induction rate were 9.8 and 100%. After 3 weeks, 2–3 cm shoots were rooting on 1/2 MS medium containing 8% (w/v) agar and 3% (w/v) sucrose supplemented with 1.0 mg/L 6-BA + 0.2 mg/L NAA. Moreover, we optimized Agrobacterium-mediated transformation using the GUS gene transient expression system. The best condition for obtaining higher transformation rate consisted of the use of fresh explants to which 100 μM acetosyringone was added for a co-culture time of 10 min, the OD value of Agrobacterium liquid is 0.5 at 600 nm. These data provide an important basis for the application of other trait gene in the improvement of jute fiber quality.     

Evidence for internalization of Escherichia coli into the aerial parts of maize via the root system

Escherichia coli introduced into the hydroponic growing medium of maize plants was detected 48 h later in the shoot. Decapitation of root tips or severing of the plant root system at the root-shoot junction enhanced bacterial internalization. The density of the bacteria in shoots of plants with damaged roots or removed root systems was 27.8 and 23.9 times higher than that in plants with intact roots, respectively. The concentration of viable cells in the hydroponic solution decreased over time from 9.3 x 10(6) CFU/ml at the time of inoculation to 8.5 x 10(1) CFU/ml 4 days thereafter. The number of E. coli cells associated with the roots also decreased with time, but a significant decline appeared only at 4 days postinoculation. At the time of sampling for E. coli presence in the shoot, 10(2) CFU/ml was present in the nutrient solution and 8 x 10(3) CFU/g was associated with the roots. The present study is the first to demonstrate internalization of E. coli via the root in a monocotyledonous plant.     

Fractionation of Stable Zinc Isotopes in the Field-Grown Zinc Hyperaccumulator Noccaea caerulescens and the Zinc-Tolerant Plant Silene vulgaris

Stable Zn isotope signatures offer a potential tool for tracing Zn uptake and transfer mechanisms within plant-soil systems. Zinc isotopic compositions were determined in the Zn hyperaccumulator Noccaea caerulescens collected at a Zn-contaminated site (Viviez), a serpentine site (Vosges), and a noncontaminated site (Sainte Eulalie) in France. Meanwhile, a Zn-tolerant plant ( Silene vulgaris ) was also collected at Viviez for comparison. While δ(66)Zn was substantially differentiated among N. caerulescens from the three localities, they all exhibited an enrichment in heavy Zn isotopes of 0.40-0.72‰ from soil to root, followed by a depletion in heavy Zn from root to shoot (-0.10 to -0.50‰). The enrichment of heavy Zn in roots is ascribed to the transport systems responsible for Zn absorption into root symplast and root-to-shoot translocation, while the depletion in heavy Zn in shoots is likely to be mediated by a diffusive process and an efficient translocation driven by energy-required transporters (e.g., NcHMA4). The mass balance yielded a bulk Zn isotopic composition between plant and soil (Δ(66)Zn(plant-soil)) of -0.01‰ to 0.63‰ in N. caerulescens , indicative of high- and/or low-affinity transport systems operating in the three ecotypes. In S. vulgaris , however, there was no significant isotope fractionation between whole plant and rhizosphere soil and between root and shoot, suggesting that this species appears to have a particular Zn homeostasis. We confirm that quantifying stable Zn isotopes is useful for understanding Zn accumulation mechanisms in plants.     

Phytoremediation of mercury and organomercurials in chloroplast transgenic plants: enhanced root uptake, translocation to shoots, and volatilization

Transgenic tobacco plants engineered with bacterial merA and merB genes via the chloroplast genome were investigated to study the uptake, translocation of different forms of mercury (Hg) from roots to shoots, and their volatilization. Untransformed plants, regardless of the form of Hg supplied, reached a saturation point at 200 microM of phenylmercuric acetate (PMA) or HgCl2, accumulating Hg concentrations up to 500 microg g(-1) with significant reduction in growth. In contrast, chloroplast transgenic lines continued to grow well with Hg concentrations in root tissues up to 2000 microg g(-1). Chloroplasttransgenic lines accumulated both the organic and inorganic Hg forms to levels surpassing the concentrations found in the soil. The organic-Hg form was absorbed and translocated more efficiently than the inorganic-Hg form in transgenic lines, whereas no such difference was observed in untransformed plants. Chloroplast-transgenic lines showed about 100-fold increase in the efficiency of Hg accumulation in shoots compared to untransformed plants. This is the first report of such high levels of Hg accumulation in green leaves or tissues. Transgenic plants attained a maximum rate of elemental-Hg volatilization in two days when supplied with PMA and in three days when supplied with inorganic-Hg, attaining complete volatilization within a week. The combined expression of merAB via the chloroplast genome enhanced conversion of Hg2+ into Hg,0 conferred tolerance by rapid volatilization and increased uptake of different forms of mercury, surpassing the concentrations found in the soil. These investigations provide novel insights for improvement of plant tolerance and detoxification of mercury.     

青钱柳悬浮细胞的培养及其基质消耗的规律

青钱柳为我国特有的胡桃科青钱柳属单种属珍稀植物,也是国家重点保护的濒危植物之一,青钱柳叶含三萜、黄酮、多糖及微量元素等活性成分,具有降糖、调脂、增强免疫等多种生理活性和药理功能,是很好的天然保健食品资源。本文建立青钱柳细胞悬浮培养体系,测定悬浮培养细胞的生长曲线,并研究了培养代数、接种量、装液量、pH值和激素组合对青钱柳悬浮体系建立的影响,同时研究了悬浮培养青钱柳细胞对培养液中主要基质的消耗规律。结果表明:适合青钱柳悬浮培养的培养基为:MS+0.1 mg/L2,4-D+0.5 mg/L NAA+1 mg/L KT+30 g/L蔗糖,接种量为8%,摇瓶装液量的体积分数为40%,初始pH 5。青钱柳细胞生长与碳源、氮源和磷的消耗存在着密切关系,在培养8 d,糖和PO43-基本消耗完毕;在氮源的吸收上,NH4+优于NO3-,NH4+的吸收基本上是呈直线下降。     

Impacts and recovery of the Deepwater Horizon oil spill on vegetation structure and function of coastal salt marshes in the northern Gulf of Mexico

We investigated the impacts of the Deepwater Horizon (DWH) oil spill on two dominant coastal saltmarsh plants, Spartina alterniflora and Juncus roemerianus, in the northern Gulf of Mexico and the processes controlling differential species-effects and recovery. Seven months after the Macondo MC 252 oil made landfall along the shoreline salt marshes of northern Barataria Bay, Louisiana, concentrations of total petroleum hydrocarbons in the surface 2 cm of heavily oiled marsh soils were as high as 510 mg g(-1). Heavy oiling caused almost complete mortality of both species. However, moderate oiling impacted Spartina less severely than Juncus and, relative to the reference marshes, had no significant effect on Spartina while significantly lowering live aboveground biomass and stem density of Juncus. A greenhouse mesocosm study supported field results and indicated that S. alterniflora was much more tolerant to shoot oil coverage than J. roemerianus. Spartina recovered from as much as 100% oil coverage of shoots in 7 months; however, Juncus recovered to a much lesser extent. Soil-oiling significantly affected both species. Severe impacts of the Macondo oil to coastal marsh vegetation most likely resulted from oil exposure of the shoots and oil contact on/in the marsh soil, as well as repeated oiling events.     

利用麦芽根提取液发酵生产酵母菌体蛋白

利用麦芽根提取液在500ml摇瓶和5L罐规模上探讨发酵生产酵母菌体蛋白的工艺可行性。实验取得了良好的效果,500ml摇瓶生产酵母的得率达到36%;5L罐规模发酵生产酵母,发酵结束后酵母干重达到2g/L,对糖的转化率达到40%。采用两种发酵规模,发酵结束后提取液中α-氨基氮的含量都下降了20%。     

Characterization of a lead hyperaccumulator shrub,Sesbania drummondii

Lead phytoextraction can be economically feasible only when the developed systems employ high biomass plants that can accumulate greater than 1% Pb in their shoots. In this study Sesbania drummondii, a leguminous shrub occurring in the wild, was used to demonstrate its capability for greater than 1% Pb accumulation in shoots when grown in a Pb-contaminated nutrient solution. Shoot concentrations of >4% Pb were obtained from Sesbania plants grown on modified Hoagland's solution containing 1 g Pb(NO3)2/L. The accumulation of Pb in the tissue was found to be dependent on the concentration of Pb in the nutrient solution. Addition of EDTA (100 microM) in the medium containing 1 g Pb(NO3)2/L increased uptake by 21%. Lower pH also favored Pb translocation to shoot. Results also indicate the path of Pb transport through root tissues. Scanning electron microscopy revealed the distribution of Pb granules in the cells from epidermis to the central axis, indicating both apoplastic and symplastic modes of transport. Transmission electron microscopy and X-ray microanalysis of root sections demonstrated the localization of Pb granules in the plasma membrane and cell wall, and also in the vacuoles. This investigation shows that S. drummondii satisfies the prerequisites for a hyperaccumulator, and thus might be useful, particularly, in the restoration of disturbed vegetation.     

发酵法制备苦竹笋膳食纤维工艺条件优化

通过单因素试验和正交试验,探讨了乳酸菌发酵法制备苦竹笋膳食纤维的发酵条件.结果表明:在竹笋浆中加入3％脱脂奶粉和0.5％蔗糖,接入4％ (v/v)的嗜热链球菌与保加利亚乳杆菌配比为1∶ 1的发酵剂,在41℃条件下恒温发酵20h,有最高的总膳食纤维和可溶性膳食纤维收得率.将发酵浆汁过滤、真空干燥、粉碎,制得的苦竹笋膳食纤维产品呈乳白色、口感细腻、有苦竹特有的清香风味,其持水力为8.43g/g,溶胀性为3.52mL/g,总膳食纤维和可溶性膳食纤维含量分别为76.87％、15.73％.     

Chemical fingerprinting and bioactivity of Amazonian Ecuador Croton lechleri Müll. Arg. (Euphorbiaceae) stem bark essential oil: A new functional food ingredient?

Croton lechleri essential oil has been obtained by steam distillation of fresh stem bark from Amazonian Ecuador adult plants (yield: 0.61 ml/kg [0.061%]; density: 1.01 g/ml), and then chemically characterised by GC (Gas Chromatography) and GC–MS (gas chromatography–mass spectrometry). Seventy-four chemicals were detected and identified; the most abundant in descending order, were the sesquiterpenes sesquicineole (17.29%), α-calacorene (11.29%), 1,10-di-epi-cubenol (4.75%), β-calacorene (4.34%) and epi-cedrol (4.09%). Monoterpenes checked with a relative peak area higher than 2.0% were α-pinene (2.01%), p-cymene (2.61%), limonene (4.20%) and borneol (2.67%). The structure of the main chemicals were confirmed by GC–MS and ¹H NMR analyses. Spectrophotometric 1,1-diphenyl-2-picrylhydrazyl (DPPH) and DPPH-(high performance) thin layer chromatography (DPPH-(HP)TLC) bioautographic assays showed a lower radical scavenging capacity (IC₅₀) with respect to commercial thyme essential oil and BHA (butylated hydroxyl anisole), pointing out, however, that the C. lechleri essential oil fraction, characterised by α-calacorene, β-calacorene and δ-cadalene, was the most involved in the bioactivity. Similar results were obtained with β-carotene bleaching assay, where the IC₅₀ values were 0.291 ± 0.024 mg/ml for C. lechleri essential oil, 0.164 ± 0.013 and 1.34 × 10⁻⁴ ± 10⁻⁵ mg/ml for thyme essential oil and BHA, respectively. (HP)TLC-bioautographic assay performed with Gram positive and Gram negative bacteria revealed a minimum inhibitory concentration (MIC) values comprised between 0.10 mg/ml (Escherichia coli) and 10.10 mg/ml (for e.g. Pseudomonas aeruginosa), and the fraction mainly characterised by sesquicineole (97.38%) as the most involved in antibacterial capacity. Ames test employing Salmonella typhimurium TA98 and TA100 with and without a metabolic activation mixture (S9 mix) demonstrated the absence of mutagenicity of the C. lechleri essential oil between a concentration range of 10⁻² and 100 mg/plate. The same results were achieved by Saccharomyces cerevisiae D7 strain assay. An interesting mutagen-protective efficacy was evidenced by a 30% and 33% revertants reduction of TA98 strain treated with 2-aminoanthracene and nitrofluorene (2 μg/plate), suggesting, above all, the possibility to employ C. lechleri essential oil as a new flavouring protective ingredient for foods or dietary supplements against potential mutagens formed during cooking and/or processing in general.     

Fatty acids in tea shoots (Camellia sinensis (L.) O. Kuntze) and their effects on the growth of retinal RF/6A endothelial cell lines

Chemo-protective effects of tea on ocular diseases were recorded in Chinese pharmacopoeia about 2000 years ago by eating tea. In the present study, contents of fatty acids (FAs) in tea shoots were determined by capillary GC; and the growth of RF/6A cells was also investigated by exposure to various representative FAs existing in tea shoots with pathologically relevant concentrations (40-500 microM) by ameliorated MTT assay and flow cytometry. Electron spin resonance (ESR) was used to measure oxygen consumption and investigate the free radical scavenging ability of linoleic acid (LA). Results showed that the most abundant long chain FAs were palmitic, linoleic, and alpha-linolenic acid in tea shoots; some RF/6A cells became suspended in culture medium treated by a high dose of both saturated and unsaturated FAs, but no apoptosis was observed. Moreover, it seemed that those FAs with different structure had various effects on the cell proliferation at their relatively low concentrations, LA expressed antioxidant activity in this study, which might be an important mechanism on the protection of eyes.     

夏枯草中16种酚类化合物含量的测定及其与抗氧化活性的相关性分析

目的:采用液相色谱-串联质谱法（LC-MS/MS）测定24批夏枯草中16种酚类化合物的含量,并采用灰色关联分析和偏最小二乘回归分析方法探讨酚类化合物与抗氧化能力的相关性。方法:夏枯草样品用80%甲醇超声提取,并基于LC-MS/MS建立夏枯草中16种酚类化合物的含量测定方法,以Waters ACQUITY UPLC BEH C₁₈（2.1 mm×100 mm,1.7 μm）色谱柱为固定相,以0.1%甲酸-乙腈为流动相在体积流量为0.4 mL/min条件下进行梯度洗脱,负离子多反应监测模式检测。以DPPH自由基清除能力、ABTS自由基清除能力和铁离子还原能力评价夏枯草的抗氧化活性。结果:16种酚类化合物在各自浓度范围内线性关系良好,相关系数r均大于0.99,精密度、重复性、稳定性和回收率良好。体外抗氧化实验证明夏枯草具有较强的清除ABTS、DPPH自由基和铁离子还原能力,灰色关联分析和偏最小二乘回归分析结果表明迷迭香酸、咖啡酸、芦丁、金丝桃苷、异槲皮苷对于抗氧化的贡献较大。结论:本研究建立了同时测定夏枯草中16种酚类化合物的LC-MS/MS方法,进一步通过相关性分析确定了夏枯草抗氧化的主要活性成分,从而为夏枯草产品的质量控制与开发利用提供科学依据。     

灵芝真菌摇瓶发酵条件优化研究

发酵培养条件中接种量、摇瓶转速、装液量对灵芝真菌生长及产多糖都有不同程度的影响。正交试验分析表明,接种量的影响显著。优化灵芝真菌发酵培养的条件为接种量10%,摇瓶转速150r/min,装液量125mL于500mL三角瓶中。此研究为以后灵芝真菌发酵罐进一步放大培养提供了依据。     

In vitro culture of Pandanus amaryllifolius and enhancement of 2‐acetyl‐1‐pyrroline,the major flavouring compound of aromatic rice,by precursor feeding of L‐proline

Shoots, plantlets and semi‐differentiated callus (SDC) cultures of Pandanus amaryllifolius capable of producing high levels of basmati rice flavour were established in vitro using Murashige and Skoog nutrient medium. A total of 10% of the initial explants responded to produce shoot cultures in the presence of benzylamino purine (BAP) (0.5 mg L^?1) and glutamine (100 mg L^?1). Leaf explants and basal portions of shoots produced SDC whereas elongated in vitro shoots could be continuously multiplied, using BAP (1.5 mg L^?1) and kinetin (Kn) (1.0 mg L^?1), and rooted in half‐strength medium for ex vitro cultivation leading to a process of micropropagation. Steam‐distillation extraction (SDE) followed by gas chromatography‐mass spectrometry (GC‐MS) analysis of various cultured organs and spent liquid medium used for SDC revealed the presence of 2‐acetyl‐1‐pyrroline (2‐AP) to various extents. This 2‐AP compound has been identified as the major flavouring compound of scented basmati and other scented rice varieties. 2‐AP was found to be highest, on a fresh weight basis, in SDC (19.7 mg kg^?1) on the 40th day, whereas in vitro roots, shoots and field leaves (of one‐year‐old plant) had lower levels of 15, 6.8 and 14 mg kg^?1, respectively. Further enhancement of 2‐AP in SDC using precursor was possible by feeding into medium 1 mmol L^?1 of L ‐proline where a highest level of 21.67 ppm of 2‐AP accumulated on the seventh day whereas a higher level of 2 mmol L^?1 of L ‐proline suppressed 2‐AP levels. The present report is the first on the tissue culture studies of P. amaryllifolius where continuous production of plantlets as well as synthesis of high levels of 2‐AP has been documented. Copyright © 2005 Society of Chemical Industry     

Major chemotypes and antioxidative activity of the leaf essential oils of Cinnamomum osmophloeum Kaneh. from a clonal orchard

Essential oils of 92 cutting clones from a clonal orchard of Cinnamomum osmophloeum Kaneh. were obtained by hydrodistillation and characterised by gas chromatography–mass spectrometry. Our results showed that the yields of essential oils ranged between 0.09% and 2.65% (vol/fresh wt). The constituents of essential oils varied among samples. The major chemotypes classified in the individual cutting clones were cinnamaldehyde (50 plants, representing 50–95% of the total volatiles), linalool (1 plant, 73.3%), β-cubebene (2 plants, 59.4% and 78.7%), and cinnamyl acetate (1 plant, 61.8%). The antioxidant activities of the four chemotypes were determined using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The antioxidant activities of the essential oil decreased in the order of cinnamyl acetate > cinnamaldehyde > β-cubebene > linalool. Indigenous cinnamon oil extract showed a good free radical-scavenging capacity at all concentrations studied, except at 2 μg/ml. The scavenging activity increased with increasing concentration of the extract. The capability of the four essential oil chemotypes to reduce the stable radical, DPPH, to DPPH-H was assayed by a decrease in the IC₅₀ values of 10.4 (cinnamyl acetate type) to 29.7 (linalool type) μg/ml. These results suggest that the leaf essential oil of C. osmophloeum possesses chemical compounds with antioxidant activity which can be used as natural preservatives in food and/or by the pharmaceutical industry. Trees in this plantation which can be used for further propagation for the production of chemotypes of interest were identified.     

Concentrating sulphur-containing flavour from Toona sinensis shoots using corn oil with and without aqueous dispersion

Toona sinensis (TS) shoot is a seasonal and quick deteriorating vegetable with unique alliaceous flavour. In this study, corn oil was used to concentrate the sulphur-containing compounds responsible for the unique TS flavour with and without aqueous dispersion. The level of sulphur-containing compounds in TS shoots was 0.32 μg g⁻¹ and concentrated to 2.34 μg g⁻¹ in the corn oil with aqueous dispersion. The sulphur-containing compounds, trans-2-Mercapto-3,4-dimethyl-2,3-dihydrothiophene and (E,Z)-Di-1-propenyldisulphide, were identified in the corn oil, while they were not detected in the oil without aqueous dispersion. Based on sensory and electronic nose analysis, the aroma of corn oil with aqueous medium extraction had stronger alliaceous aroma than TS shoots and the extraction corn oil without aqueous dispersion. With aqueous dispersion assistance, the sulphur-containing aroma compounds in TS shoots were effectively concentrated in corn oil. The flavour-enriched oil could serve as a flavour ingredient to deliver TS shoots aroma for different food applications.     

海洋细菌NBRC10260产琼胶酶发酵条件优化

通过正交试验法对产琼胶酶海洋菌株NBRC102603发酵条件进行优化,优化培养基为:蛋白胨4.0g/L、酵母粉1.25g/L、琼胶粉5.0g/L;在装液量150mL(500mL三角瓶)、28℃、150r/min、接种量为1%条件下发酵48h酶活力达到最高,为56.89U/mL,比未优化前提高了2.01倍.