Some Responses of Two Nicotiana tabacum L. Cultivars Exposed to Vanadium

The effect of exposure to different vanadium (V) concentrations was studied in Nicotiana tabacum L. (cv. ‘Burley’ and cv. ‘Virginia’). In both cultivars, the vanadium did not affect the percentage of germination but root and shoot growth was inhibited, especially with the 80 μM dose. An altered root morphogenesis in vanadium growth plants was observed at the end of the experiment. The highest V accumulation was found in roots and the results showed a direct correlation between V content and V supply (P?≤?0.01). The V concentrations did not modify nicotine content in the cv. ‘Burley’, but in the cv. ‘Virginia’ the highest nicotine content was found in vanadium exposed plants (P?≤?0.05). The results suggest that these V concentrations may have a possible elicitor effect on alkaloid synthesis in N. tabacum L. cv. ‘Virginia’, and that this cultivar has a higher V sensitivity than the cv. ‘Burley’.     

镉胁迫下小麦根系的生理生态变化

本文通过水培和砂培两种方法 ,研究了镉胁迫下小麦 (TriticumaestivmL .)根系的生理生态变化。通过研究镉对小麦根系生长发育状况 ,根系活力 ,根系对矿质元素的吸收 ,探讨镉胁迫下植物根系的生理生态效应。研究结果表明 :镉影响根系的长度、生物量、体积和根系活力。Cd2 + 在低浓度 (处理浓度低于 5mg/L)作用下 ,随处理浓度的升高 ,刺激小麦根系的长度、生物量、体积相应地升高 ;当处理浓度高于相应浓度时 ,根长度、生物量、体积相应随浓度升高而降低。镉胁迫下根系活力受到抑制。水培和砂培中 ,镉对根系的影响趋势一致 ,但是影响幅度有差异。砂培好于水培。镉影响小麦根对矿质元素的吸收 ,Ca、Cu、Fe、K、Mg、Mn、Na、Zn吸收情况不太一致。Ca、Cu、Fe、Mg、Mn、Na的吸收量随Cd2 + 浓度升高而增加 ,K、Zn的吸收量随Cd2 + 浓度升高而减少     

Identification of fructo- and malto-oligosaccharides in cured tobacco leaves (Nicotiana tabacum)

Fructo-oligosaccharides (FOSs) and malto-oligosaccharides (MOSs) in cured tobacco leaves ( Nicotiana tabacum ) were detected and quantified using high-performance liquid chromatography (HPLC) coupled with electrospray ionization (ESI) tandem mass spectrometry (MS/MS). These oligosaccharides were present in several tobacco materials including flue-cured tobacco, sun/air-cured tobacco, and cut filler of commercially available tobacco products, but were not detected in air-cured tobacco. The changes in these oligosaccharides during storage were also investigated. The results revealed that MOSs simply decreased under a warm atmosphere and FOSs increased. In addition, the formation of FOSs in cured tobacco leaves occurred in the presence of sucrose. With regard to FOSs, it has been reported that green tobacco leaves do not contain FOSs such as kestose, nystose, and fructosyl-nystose. The results of a model test suggested that the changes in FOS amount were caused by enzymatic reactions.     

烟草染色体倍性快速鉴定方法

摘要: 对两个杂交组合(G28 × NC2326和K326 × Coker176) F1烟草 (Nicotiana tabacum) 花药培养诱导出763个不同倍性植株。基于植株的花和种子结实率常规鉴定倍性水平比较，用气孔保卫细胞叶绿体数目预测植株倍性准确率达93.52%。表明采用气孔保卫细胞叶绿体计数法可以在苗期快速、准确地确定植株染色体倍性。同时, 在移栽前间接地鉴定、筛选出叶绿体数<14的单倍体苗，作进一步秋水仙碱加倍处理，以减少对单倍体材料的浪费，加快DH群体构建速度。     

The Contribution of Foliar Exposure to Boron Toxicity

Boron toxicity is commonly considered in terms of plant B uptake and accumulation. This work tested the hypothesis that foliar exposure of water with high B content leads to more severe toxicity reactions in plants as compared to exposure to high B simply through the soil solution. Growth and B uptake were studied in corn, tomatoes, onions, celery and radish where B laden water was applied with and without a component of foliar contact. Increased visual symptoms of B toxicity and decreased yields were found in plants with foliar applied B for all of the crops, while associated increased B tissue concentrations were not measured. The results imply that the relative toxicity of B entering through the leaves is greater than that of B entering via roots. Biomass reduction due to B was found to be a function of neither absolute B accumulation nor relative B mobility in the plant.     

Increasing expression of an anti-picloram single-chain variable fragment (ScFv) antibody and resistance to picloram in transgenic tobacco (Nicotiana tabacum)

Systematic research involving four chimeric gene constructions designed to express the same anti-picloram single-chain variable fragment (scFv) antibody is described. Agrobacterium-mediated transformation produced at least 25 transgenic tobacco plants with each of these, and the number of T-DNA loci in each plant was determined using kanamycin-resistance segregation assays. The relative amounts of active and total scFv in each plant were evaluated using quantitative enzyme-linked immunosorbent assay and immunoblot technologies, respectively. No significant differences in scFv activity were found among the four groups of single-locus plants, although the 35S/M construct was found to produce significantly more total anti-picloram scFv than the other three constructs. A dose-response bioassay involving T(1) seedlings from several of the highest expressers of active scFv demonstrated resistance to a constant exposure of picloram at 5 x 10(-)(8) M. Other approaches for increasing antibody-based herbicide resistance are discussed, as further improvements are needed before practical application of this technology.     

高粱SbSKIP基因的克隆及其在烟草中的抗旱功能分析

SKIP(ski-interacting protein)是一种RNA代谢相关蛋白,在植物抵抗非生物胁迫伤害中起着很重要的调节作用,本研究克隆了高粱(Sorghum bicolor)SbSKIP基因,cDNA编码区全长1 485 bp,编码494个氨基酸;进化树分析表明,高粱SbSKIP基因编码的氨基酸序列与节节麦(Aegilops tauschii)相似性为52％;定量PCR分析表明,在模拟干旱条件下SbSKIP基因表达量上调,在干旱处理16h后,表达量显著增加了2倍以上.构建植物表达载体pSH-SbSKIP,利用农杆菌(Agrobacterium tumefaciens)介导的叶盘法遗传转化烟草(Nicotiana tabacum),获得25个转基因植株.选取3个不同株系TP4、TP9和TP13,在不同浓度甘露醇模拟干旱条件下对种子发芽率和幼苗期进行抗旱性分析,结果发现,在300 mmol/L甘露醇处理10d,种子的发芽率比野生型高60％以上,而且从苗期根的生长发现,野生型根的生长明显受到抑制.在自然条件下生长的烟草幼苗,用20％ PEG 6000处理14d,结果显示,转基因烟草正常生长,而野生型烟草大部分叶片黄化甚至出现萎蔫,其中转基因植株超氧化物歧化酶(super-oxide dismutase,SOD)的平均活性值比野生型高91.2％,H2O2和丙二醛(malondialdehyde,MDA)含量分别比野生型降低了42％和32.7％,可溶性糖(soluble sugar)含量达野生型的1.1倍.结果表明,SbSKIP基因表达提高了烟草植株的干旱耐受能力.本研究为进一步研究SbSKIP基因功能提供依据,同时该基因的克隆和功能分析可为创制转基因抗旱材料提供基础资料.     

草甘膦对烟草叶片超微结构的影响

草甘膦是农业生产中广泛使用的广谱非选择性除草剂,它抑制5-烯醇丙酮酸莽草酸-3-磷酸合成酶。该酶是莽草酸途径中的关键酶,广泛存在于微生物与植物中。用30mmol／L草甘膦处理烟草叶片2、6、12、24、48h,结果显示,处理12h内烟草叶片无明显变化,24、48h后叶片黄化,并出现坏死。对各处理时期烟草叶片的超微结构研究显示,草甘膦处理导致烟草叶片细胞的叶绿体基粒片层结构被破坏,线粒体电子密度下降。这些结果提示,草甘膦通过阻碍植物的光命作用和呼晖作用面导致叶片坏死。     

转PSAG12-BAS1基因抑制烟草叶片的衰老

衰老被认为是烟草(icotiana tabac um)叶片发育的最后阶段,伴随着叶绿素,脂类等降解,严重影响了光合产物的积累,导致作物产量降低、品质下降.因此,利用转基因技术使烟草在生长期间衰老延迟,光合产物量增加,从而增加产量,同时在收获之后,延缓衰老的叶片,可以维持烟草的新鲜程度,解决储存及运输问题.本研究利用农杆菌(Agrobacterium tumefaciens)介导的遗传转化法将含有衰老相关基因12 (senescence-associated gene 12,SAG12)启动子驱动光敏色素B激活标签的抑制蛋白1(phyB activationtagged suppressor1,BAS1)基因表达的元件导入烟草中,经抗性筛选和PCR鉴定,共获得45株转基因植株,其中有8株转基因烟草叶片具有衰老延缓现象.在叶片开始衰老时对野生型和转BAS1基因烟草叶片叶绿素含量、保护酶活性检测以及植物生长期状态进行观察测定,结果表明,转BAS1烟草植株叶绿素含量从顶端到基部均高于野生型;野生型和转BAS1基因烟草超氧化物歧化酶(super-oxide dismutase,SOD)活性和丙二醛(malondialdehyde,MDA)含量分析表明,转BAS1烟草植株中SOD活性比野生型高了31.98％,MDA含量比野生型降低了48.28％,通过对烟草生长发育过程观察,转基因烟草比野生型烟草衰老延缓10～15 d.在烟草叶片开始衰老时测定野生型和转BAS1基因植物细胞分裂素含量,结果发现,野生型烟草细胞分裂素的含量比转基因烟草降低了40.2％,上述结果说明,转BAS1基因延缓了烟草叶片的衰老,与细胞分裂素含量、保护性酶活性提高以及衰老性启动子启动有关.本研究为进一步研究SAG12-BAS1基因功能机制提供理论依据,同时该基因为创制转基因抗衰老材料提供了基础.     

Enhancement of callose production by a combination of aluminum and iron in suspension-cultured tobacco (Nicotiana tabacum) cells

In nutrient medium, aluminum (A1) enhances ferrous ion [Fe(II)] -mediated per oxidation of lipids, which results in the loss of the plasma membrane integrity and the accumulation of A1 in tobacco cells. Under these conditions, the mechanism of callose production and possible involvement of callose in the accumulation of Al were investigated. Callose production was enhanced by both Al and Fe(II), but not by A1 or Fe(II) alone, and the enhancement was inhibited by a lipophilic antioxidant, suggesting that the enhancement of callose production is caused by the A1-enhanced, Fe(II)-mediated peroxidation of lipids. The enhancement of callose production depended on the presence of external Ca²⁺ in the treatment medium. The activity of β-l,3-glucan synthase in the microsomes was increased several times by the addition of Ca²⁺ in the assay medium, although the activity in the microsomes was reduced by the treatment of cells with Al and Fe(II) together. Therefore, it is likely that callose production is enhanced by exogenous Ca²⁺ via the AI-enhanced, Fe(II)-mediated peroxidation of lipids. During the exposure of the cells to Al and Fe(II), callose production started and increased simultaneously with Al accumulation. However, the digestion of callose in the cell wall materials prepared from the A1-treated cells by laminarinase did not release A1, suggesting that callose is not involved in the binding or trapping of A1.     

烟草NtMTPC4启动子的克隆与缺失分析

组织特异性启动子是基因工程研究及实际应用中的重要工具。为了研究烟草NtMTPC4启动子的表达特性,采用实时荧光定量PCR方法分析烟草金属耐受蛋白C4(MTPC4)基因NtMTPC4在烟草不同组织中的表达模式,并利用PCR技术克隆得到NtMTPC4的上游启动子NtMTPC4-P。根据调控元件的分布对NtMTPC4-P进行不同程度的缺失,获得了NtMTPC4-P1、NtMTPC4-P2和NtMTPC4-P3缺失体;构建全长NtMTPC4-P和不同缺失体的植物表达载体,并通过花序浸染法转化拟南芥,对获得的转基因拟南芥进行GUS组织化学染色分析。结果表明,NtMTPC4基因的表达具有组织特异性,其在花中的表达量最高。NtMTPC4-P全长2 287 bp,含有CAAT-box、TATA-box、GTGANTG10和POLLEN1LELAT52等顺式作用元件和调控元件。GUS组织化学染色结果表明,全长启动子NtMTPC4-P和不同缺失体都能特异性地驱动GUS基因在转基因拟南芥花粉中的表达。本研究结果为通过基因工程技术在花粉中特异表达目的基因提供了新的调控元件。     

Physiological Effects of Exposure to Arsenic,Mercury, Antimony and Selenium in the Aquatic Moss Fontinalis antipyretica Hedw.

This study assessed the effect of ambient air pollution on leaf characteristics of white willow, northern red oak, and Scots pine. Willow, oak, and pine saplings were planted at sixteen locations in Belgium, where nitrogen dioxide (NO₂), ozone (O₃), sulfur dioxide (SO₂), and particulate matter (PM₁₀) concentrations were continuously measured. The trees were exposed to ambient air during 6 months (April–September 2010), and, thereafter, specific leaf area (SLA), stomatal resistance (R _s), leaf fluctuating asymmetry (FA), drop contact angle (CA), relative chlorophyll content, and chlorophyll fluorescence (F _v/F _m) were measured. Leaf characteristics of willow, oak, and pine were differently related to the ambient air pollution, indicating a species-dependent response. Willow and pine had a higher SLA at measuring stations with higher NO₂ and lower O₃ concentrations. Willow had a higher R _s and pine had a higher F _v/F _m at measuring stations with a higher NO₂ and lower O₃ concentrations, while oak had a higher F _v/F _m and a lower FA at measuring stations with a higher NO₂ and lower O₃ concentrations. FA and R _s of willow, oak, and pine, SLA of oak, and CA of willow were rather an indicator for local adaptation to the micro-environment than an indicator for the ambient air pollution.     

Responses of Young Trees (Five Species in a Chamber Exposure) to Near-Ambient Ozone Concentrations

This investigation is intended to add to the quantitative information about the sensitivity of European deciduous tree species to environmentally realistic ozone (O₃) exposure in respect to the established critical level of an AOT40 of 10 ppm.h (6-month growing season, daylight hours). Cuttings (without leaves) of Fagus sylvatica L., Sorbus aucuparia, L., Carpinus betulus L., Fraxinus excelsior L., and cuttings and seedlings of Prunus serotina Ehrh. were exposed during one growing season either to filtered air, to which 50 % of ambient O₃ concentration was added, or to 50 % + 30 ppb O3, resulting in a final AOT40 of 0.3 and 20.7 ppm.h, respectively. The foliage formed per tree varied between and within the species, but was not significantly modified by O₃, whereas the number of symptomatic leaves per tree significantly increased in the 50 % + 30 ppb O₃ regime. By mid July light-green spots appeared in the leaves (except C. betulus), which developed into stippling (F. excelsior), red (P. serotina) or necrotic spots by September. The CO₃-assimilation rate decreased more with increasing visual symptoms (earliest in 20- day-old leaves) than with age-dependent leaf discoloration in F. sylvatica, F. excelsior, and P. serotina (not in C. betulus). The dark-adapted photosystem II quantum yield (Fv/Fm) slightly declined with leaf age, but a considerable reduction became apparent in 107-day-old leaves with O₃-symptoms only. By late morning yield reduction in light-adapted leaves were exaggerated in such leaves from the 50 % + 30 ppb O₃ regime. The above mentioned responses were not reflected in significant changes of the net biomass production during the experiment. The critical level, therefore, is based on visual and functional symptoms rather than on production.     

烟草K346品种叶数、株高变异株的RAPD分析

烟草是叶用作物，其叶数与经济产量密切相关。RAPD技术已被广泛应用于揭示烤烟品种及其它作物突变体基因组DNA的差异和基因定位旧。本实验利用RAPD技术探讨烟草变异株和对照株的遗传物质差异，为探明烟草变异株的叶数或株高突变基因位点提供参考。