m型硫氧还蛋白对马铃薯Y病毒侵染烟草的影响

为进一步明确病毒与寄主间的相互作用关系,通过同源比对在烟草细胞中克隆到具有m型硫氧还蛋白(m-type thioredoxin)特征的基因,暂命名为Nt Trm。利用原生质体瞬时转化技术、病毒诱导的基因沉默技术(VIGS)、半定量-PCR以及Northern blot检测技术研究Nt Trm的表达以及Nt Trm表达与PVY积累的关系。结果表明,在PVY接种10 d后红花大金元叶片中Nt Trm表达明显上调;在本氏烟草叶片中Nt Trm下调显著促进了PVY在烟草叶片中的积累;而在烟草原生质体中Nt Trm过量表达则会明显抑制病毒RNA的积累。初步说明烟草细胞内编码m型硫氧还蛋白的基因受PVY侵染而被诱导表达,这类基因的上调表达可能影响PVY在烟草细胞中的侵染。     

2003年度国家烟草专卖局科学技术进步奖获奖项目简介(II)

1　东北地区烟草马铃薯Y病毒病发生规律及防治技术研究该项目鉴定了我国烟草上的PVY共有 4个株系 :PVYO(普通株系 )、PVYN(脉坏死株系 )、PVYNS(茎坏死株系 )和PVYC(点刻条斑株系 ) ,以PVYN 为优势株系。利用CORESTA PVY合作小组提供的国际鉴别寄主 ,室内外测定比较了我国的PVYN 与国际上已报道的PVY各株系的差异 ,认为我国PVYN 与欧洲 3号株系极相似 ,而与美国的两个株系MsNr和VAM B及欧洲的其它株系差异较大 ;开展了PVYN 分子生物学研究 ,克隆获得了PVYN 的复制酶基因 (PVYN NIb)和PVYN 的外壳蛋白基因 (PV…     

烟草PVY隐性抗病基因的分子标记及其适用性

马铃薯Y病毒(Potato virus Y,PVY)是危害烟草的重要病害,种植抗病品种是经济有效的防治措施。分子标记辅助选择可提高抗病育种效率。来源于X-射线诱变的Virgin A Mutante(VAM)的隐性抗PVY基因位点(va)被广泛应用于烟草抗病育种。为了提高va位点的育种利用效率,根据烟草隐性抗PVY基因(感病基因)e IF4E-1基因序列,设计特异扩增的引物CF2GR11,开发e IF4E-1基因的分子标记,并检测了该标记与抗性的遗传距离和在常见烟草资源中的适用性。CF2GR11在云烟87、红花大金元和K326等感PVY品种可扩增出500 bp产物,在NC102、NC55和K326PVY等抗病品种无扩增条带。以抗、感PVY亲本构建的101个F2单株为定位群体,遗传连锁分析表明,CF2GR11标记与烟草PVY感病基因的遗传距离为0.99 c M。对46份PVY抗性明确的栽培烟草资源的检测表明,供试资源的标记检测结果与抗性的吻合度为100%,表明CF2GR11标记适用性高。该目的基因标记可用于抗PVY育种的辅助选择和抗PVY资源的鉴定。     

烟草种质资源抗马铃薯Y病毒病基因型鉴定

  背景和目的  从作物种质资源中进行等位基因鉴定,特别是优异等位基因的发掘和应用,是使种质资源加速转变为基因资源的关键所在。  方法  采用苗期汁液摩擦接种的方法,对烟草种质资源的马铃薯Y病毒（Potato virus Y,PVY）抗病性进行鉴定;通过烟草隐性抗PVY基因eIF4E1（又称为感PVY基因eIF4E1）等位性测验、等位基因分子标记检测和RT-PCR扩增测序,对PVY抗病资源进行基因型分析。  结果  （1）从收集到的900多份来自国内外的烟草种质资源中筛选出19份高抗PVY资源。（2）根据等位性测验结果推断19份抗源所具有的PVY抗性均由eIF4E1基因所控制。（3）等位基因分子标记检测和RT-PCR扩增测序结果将19份抗源的eIF4E1基因区分为4种突变类型。  结论  本研究结果丰富了我国对抗PVY烟草种质资源的筛选和利用的内容,为后续烟草PVY抗性优异等位基因的发掘和育种利用提供了基础材料和信息支撑。      

烟草野生种eIF4E1-S同源基因的多样性与马铃薯Y病毒抗性分析

  背景和目的  在栽培烟草中,真核生物翻译起始因子（Eukaryotic translation initiation factor 4E1,eIF4E1-S）的缺失或突变能够抗马铃薯Y病毒（Potato virus Y,PVY）侵染。为了解烟草野生种eIF4E1-S同源基因的多样性和PVY抗性状况,预测野生种含有抗PVY新基因（即不同于eIF4E1-S基因缺失或突变的基因）的可能性。  方法  本文设计了普通烟草eIF4E1-S和其同源基因eIF4E1H-T（非感病基因）的特异引物,扩增测定了34个烟草野生种的同源基因cDNA序列,分析了野生种PVY抗性与感马铃薯Y病毒属病毒eIF4E蛋白关键结构域序列（loop1和loop2）的相关性。  结果  在eIF4E1-S同源基因的系统进化树上,绒毛烟草组（Tomentosae）的4个抗PVY野生种Nicotiana otophora、N.setchelli、 N.tomentosa、 N.tomentosiformis聚成一组,loop1和loop2的氨基酸序列与eIF4E1H-T一致,这4个野生种对PVY的抗性可能与eIF4E1进化为eIF4E1H-T有关、包含抗PVY新基因的可能性较低。圆锥烟草组（Paniculatae）的4个抗PVY野生种N.benavidesii、N.raimondii、 N.cordifolia、N.knightiana聚成一组,同源基因氨基酸序列与eIF4E1-S一致率高于eIF4E1H-T,但loop1和loop2氨基酸序列相互之间差异较大,这4个野生种包含抗PVY新基因的可能性中等。与eIF4E1-S聚成一个小分支的N.glauca、N.noctiflore、N.africana高抗5个PVY分离物（包含可克服va抗性的PVY分离物）,其中N.glauca、N.noctiflore的同源基因loop1氨基酸序列与eIF4E1-S相同,loop2与eIF4E1-S之间只有1-2个氨基酸差异,N.africana同源基因loop1与eIF4E1-S和eIF4E1H-T差异较大、loop2与eIF4E1-S之间只有1个氨基酸差异（V97M）。推测这3个野生种的PVY抗性与eIF4E1的突变无关且含有新的抗PVY基因可能性高,可作为重点抗源研究利用。  结论  根据PVY侵染栽培烟草所利用的寄主因子eIF4E1-S基因的同源基因的多样性,抗PVY烟草野生种存在抗PVY新基因的可能性划分为高、中和低三档。N.glauca、N.noctiflore、N.africana含有新的抗PVY基因可能性高于其他供试野生种。      

用血清学方法检测山东烟草病毒病流行趋势

用血清学方法对烟草病毒进行检测,同时进行生物学测定和电镜观察,研究结果表明:现山东烟区烟草病毒病的流行种类与以前的报道有较大改变。其流行趋势是马铃薯 Y 病毒病(PVY)由次要病害上升为主要病害,黄瓜花叶病(CMV)依然严重,且病毒的复合感染加重。烟草黄斑坏死病(PVY—T)和烟草脉带花叶病(TVBMV)在山东省首次发现。     

病毒诱导的基因沉默防控烟草马铃薯Y病毒病研究

  背景  病毒诱导的基因沉默（virus-induced gene silencing，VIGS）是植物抗病毒侵染的一种自然机制。  方法  以马铃薯Y病毒（Potato virus Y，PVY）脉坏死株系（PVYN）的外壳蛋白（coat protein, CP）基因为靶向序列，构建烟草脆裂病毒（Tobacco rattle virus，TRV）介导的基因沉默表达载体pTRV2-CP，转化农杆菌GV3101后，与pTRV1-GV3101混合成TRV: : CP（OD₆₀₀ 0.4~0.6）喷施处理剪叶后的烟苗，测定其侵染效率。人工接种PVY于对照及TRV: : CP处理的烟苗，RT-qPCR检测、表型观察和小区试验评价TRV介导的VIGS体系对PVY侵染的沉默效果。  结果  ① 与TRV: : 00相比，接种PVY 35 d时，TRV: : CP处理的烟株中PVY累积量减少了72.8%；②VIGS表达载体45 d内能有效表达；③温室盆栽和田间小区试验TRV: : CP处理对PVY防治效果分别达到85.12%和73.08%。  结论  研究建立的VIGS体系能够沉默PVY CP基因的表达，有效防治烟草马铃薯Y病毒病，为PVY的防治提供了新的方法。      

烟草4种病毒的多重RT-PCR检测方法构建

为有效鉴定烟草的主要病毒,包括烟草普通花叶病毒(Tobacco mosaic virus,TMV)、黄瓜花叶病毒(Cucumber mosaic virus,CMV)、马铃薯Y病毒(Potato virus Y,PVY)和烟草脉带花叶病毒(Tobacco vein banding mosaic virus,TVBMV),建立了一种同时检测这4种病毒的多重RT-PCR检测方法。通过人工接种4种病毒试验,发现TVBMV在混合侵染中受TMV、CMV和PVY的拮抗作用。为提高4种病毒复合侵染下TVBMV的检测灵敏度,筛选出TVBMV中表达水平最高的PIPO基因,利用该基因结合TMV、CMV和PVY的CP基因,基于保守区域设计引物,并优化引物及模板的浓度,在一个PCR反应体系中稳定扩增获得大小分别为700、452、275和235 bp的产物。该方法实现了对多种病毒的同时检测,适用于目前大部分烟区田间病毒复合侵染的监控。     

过表达和沉默NbRbcS基因对烟草主要病毒侵染的影响

为明确Rubisco酶小亚基(Rubisco small subunit,RbcS)在烟草抵抗主要病毒侵染胁迫中的作用,以本氏烟为研究材料,利用qRT-PCR、Western blot和瞬时表达体系对烟草RbcS基因在TMV、CMV和PVY侵染中的调控作用进行系统分析。结果表明,3种病毒侵染本氏烟均引起NbRbcS在mRNA水平和蛋白水平上下调,瞬时过表达NbRbcS,病毒拷贝数均显著降低。而沉默NbRbcS,TMV、CMV和PVY拷贝数分别达到阴性对照的11.12、9.57和17.76倍。对PVY引起的斑驳叶片中深绿色和浅绿色区域分别进行qRT-PCR分析发现,在浅叶区NbRbcS mRNA的表达量只有深叶区的49.10%,但PVY的拷贝数却达到了深叶区的5.18倍。以上研究表明,RbcS大量表达可增强烟草对病毒的防御能力,烟草RbcS基因可作为潜在的抗病毒基因利用。     

烟草PVY Real-Time PCR定量检测体系的建立及应用

马铃薯Y病毒是近年来危害烟草生产的重要病毒之一,严重影响烟草的产量与品质。本研究利用DNAMAN软件对GenBank数据库中已登录的马铃薯Y病毒(Potato virus Y,PVY)全基因组序列进行序列比对,设计引物,以烟草肌动蛋白基因为内参,建立了烟草PVY的实时定量检测体系。获得的real-time PCR扩增基线平整,指数扩增明显,斜率大;稳定性和重现性好,变异系数小;循环阈值与PCR起始模板量对数之间存在良好的线性关系。与DAS-ELISA相比,该方法具有高效、灵敏、特异性强等优点,为从分子生物学水平上检测烟草中PVY提供了新的技术手段。     

Matrix effects on flavour volatiles release in dark chocolates varying in particle size distribution and fat content using GC–mass spectrometry and GC–olfactometry

Influences of matrix particle size distribution (PSD) (18, 25, 35 and 50 μm) and fat content (25%, 30% and 35%) on flavour release of dark chocolate volatiles were quantified by static headspace gas chromatography using GC–MS. Sixty-eight (68) flavour compounds were identified, comprising alcohols, aldehydes, esters, ketones, furans, pyrans, pyrazines, pyridines, pyroles, phenols, pyrones and thiozoles. From GC–olfactometry, 2-methylpropanal, 2-methylbutanal and 3-methylbutanal had chocolate notes. With cocoa/roasted/nutty notes were trimethyl-, tetramethyl-, 2,3-dimethyl-, 2,5-dimethyl-, 3(or 2),5-dimethyl-2(or 3)-ethyl- and 3,5(or 6)-diethyl-2-methylpyrazine and furfuralpyrrole. Compounds with fruity/floral notes included 3,7-dimethyl-1,6-octadien-3-ol and 5-ethenyltetrahydro-R,R,5-trimethyl-cis-2-furanmethanol. Caramel-like, sweet and honey notes were conferred by 2-phenylethanol, phenylacetaldehyde, 2-phenylethylacetate, 2,3,5-trimethyl-6-ethylpyrazine, 2-carboxaldehyde-1H-pyrrole, furancarboxaldehyde, furfuryl alcohol and 2,5-dimethyl-4-hydroxy-3(2H)furanone. There were direct relationships of fat content with 3-methylbutanal and branched pyrazines but inverse ones with 2-phenylethanol, furfuryl alcohol, methylpyrazine, phenylacetaldehyde, 2, 3, 5-trimethyl-6-ethylpyrazine and 2-carboxaldehyde-1-H-pyrrole. Particle size influenced higher alcohol, aldehyde, ester, ketone and pyrazine concentrations at all fat contents. A multivariate product space suggested flavour effects of the interacting factors.     

A Review on Mycotoxins in Food and Feed: Malaysia Case Study

Fungi are distributed worldwide and can be found in various foods and feedstuffs from almost every part of the world. Mycotoxins are secondary metabolites produced by some fungal species and may impose food safety risks to human health. Among all mycotoxins, aflatoxins (AFs), ochratoxin A (OTA), trichothecenes, deoxynivalenol (DON and T‐2 toxin), zearalenone (ZEN), and fumonisins (FMN) have received much attention due to high frequency and severe health effects in humans and animals. Malaysia has heavy rainfall throughout the year, high temperatures (28 to 31 °C), and high relative humidity (70% to 80% during wet seasons). Stored crops under such conditions can easily be contaminated by mycotoxin‐producing fungi. The most important mycotoxins in Malaysian foods are AFs, OTA, DON, ZEN, and FMN that can be found in peanuts, cereal grains, cocoa beans, and spices. AFs have been reported to occur in several cereal grains, feeds, nuts, and nut products consumed in Malaysia. Spices, oilseeds, milk, eggs, and herbal medicines have been reported to be contaminated with AFs (lower than the Malaysian acceptable level of 35 ng/g for total AFs). OTA, a possible human carcinogen, was reported in cereal grains, nuts, and spices in Malaysian market. ZEN was detected in Malaysian rice, oat, barley, maize meal, and wheat at different levels. DON contamination, although at low levels, was reported in rice, maize, barley, oat, wheat, and wheat‐based products in Malaysia. FMN was reported in feed and some cereal grains consumed in Malaysia. Since some food commodities are more susceptible than others to fungal growth and mycotoxin contamination, more stringent prevention and control methods are required.     

Non-carcinogenic effects of TCDD in animals

Exposure to TCDD and related chemicals leads to a plethora of effects in multiple species, tissues, and stages of development. Responses range from relatively simple biochemical alterations through overtly toxic responses, including lethality. The spectrum of effects shows some species variability, but many effects are seen in multiple wildlife, domestic, and laboratory species, ranging from fish through birds and mammals. The same responses can be generated regardless of the route of exposure, although the administered dose may vary. The body burden appears to be the most appropriate dosimetric. Many of the effects often attributed to TCDD are associated with relatively high doses: lethality, wasting, lymphoid and gonadal atrophy, chloracne, hepatotoxicity, adult neurotoxicity, and cardiotoxicity. Changes in multiple endocrine and growth factor sytems have been reported in a manner which is tissue, sex, and age-dependent. The most sensitive adverse effects observed in multiple species appear to be developmental, including effects on the developing immune, nervous, and reproductive systems. Such effects have been observed at maternal body burdens in the range of 30-80 ng/kg in both non-human primates and rodents. Biochemical effects on cytokine expression and metabolizing enzymes occur at body burdens which are within a factor of ten of the clearly adverse developmental responses. Thus, effects on the immune system, learning, and the developing reproductive system of multiple animals occur at body burdens which are close to those present in the background human population.     

Enhancement of Food Processes by Ultrasound: A Review

In food processing, the applications of ultrasound can be divided into two categories, namely replacing traditional technologies and assisting traditional technologies. In the latter case, the processing efficiency is enhanced and the disadvantageous of traditional technologies during processing are improved. These ultrasonic effects can be defined as ultrasonic enhancement of food processes. This review is focused on the use of ultrasound to enhance various food processes, including extraction, freezing, thawing, brining, oxidation, filtration, and drying/dehydration. The major functions of ultrasound in enhancing these processes and the factors which can affect the ultrasonic enhancement are elucidated. In the meantime, the strategies of modeling these processes enhanced by ultrasound are provided. Future studies should pay more attention to elucidate the ultrasonic effects during freezing, thawing, brining, oxidation, and filtration processes. Furthermore, when it comes to design the ultrasound equipment at the industrial level, it is better to quantify the ultrasonic effects through numerical stimulation.     

Evaluation of mycotoxin-contaminated cereals for their use in animal feeds in Hungary

In the period between December 5, 1991 and September 17, 1998, 760 maize, 367 wheat, 119 soybean, 222 barley, 85 bran, 32 triticale, 60 oat, 14 rye and 22 sunflower samples were investigated for the presence and concentration of seven fusariotoxins (T-2 toxin, zearalenone, deoxynivalenol, nivalenol, diacetoxyscirpenol, HT-2 toxin, fusarenone-X) and OTA. The comparison of analytical data with those of the relevant literature revealed that although the incidence rate and/ or concentration of Fusarium mycotoxins and OTA in Hungarian-grown cereals is occasionally considerable, the position of the country is not worse than the average of countries. Our findings indicate that soybean tends to be good substrate for trichothecene-producing fungi and the rate of contamination is regarded as substantial. The commodities were assorted into one of three quality categories. The proportion of objectionable samples was only 3.0, 2.2, 2.3 and 1.7% in maize, wheat, barley and soybean samples, respectively. However, this low rate of objection might still be a source of great economic loss. The proportion of objectionable samples was much higher in the case of bran, oat and triticale (7.1, 6.7, and 6.3%, respectively). The results of the present investigation indicate a need for regular screening for mycotoxins of importance and individual appraisal of each commodity from the point of their use in animal feeds.     

Propolis to Curb Lifestyle Related Disorders: An Overview

The natural products are gaining immense importance in the domain of nutrition to prevent various maladies and improve the quality of life. Among these, natural exudates are of significant worth as these biochemical compounds are released by various living entities having pharmacological properties for utilization in various drug developments. These natural exudates are the promising source for the discovery of new medications. Numerous bioactive moieties collected by honeybees from exudates and buds of particular trees and plants, considered to be utilized as defensive barrier with special reference to propolis. It generally contains numerous biochemical components, i.e., polyphenols, steroids, terpenoids, and amino acids. They also contain isoferulic acid, sinapinic acid, caffeic acid, and chrysin responsible for antibacterial perspectives. With special attention to propolis, it has been utilized in folk medicines due to several of its therapeutic activities, i.e., antioxidant, antidiabetic, anti-inflammatory, antiviral, and anticancer properties. In this context, it is extensively used in foodstuffs and beverages to improve health related disorders like inflammation, diabetes, heart disease, protects injured gums, and cancer insurgence. Moreover, it has been used to curtail stomatology, gastroenterology, skin lesions, and otorhinolaryngologic and respiration diseases.     

Structured biopolymer-based delivery systems for encapsulation,protection, and release of lipophilic compounds

Food-grade biopolymers, such as proteins and polysaccharides, can be used to create a diverse range of delivery systems suitable for encapsulating, protecting, and delivering lipophilic functional components, such as ω-3 rich oils, conjugated linoleic acid (CLA), oil-soluble vitamins, flavors, colors, and nutraceuticals. This article provides an overview of a number of different approaches that can be used to create structured delivery systems based on biopolymers, including molecular complexation, coacervation, thermodynamic incompatibility, moulding, and extrusion methods. These delivery systems can be produced from food-grade ingredients using simple processing operations (e.g., mixing, homogenizing, and thermal processing). The structure, production, performance, and potential applications of each type of structured delivery system are discussed.     

过度蒸煮对马铃薯风味化合物组成的影响

采用固相微萃取结合气相色谱-质谱联用仪及嗅闻技术对蒸煮30~180 min时间内的马铃薯产品风味物质进行测定,分析过度蒸煮对马铃薯感官品质及风味的影响规律,在不同的蒸煮时间内分别检测到39、26、23、21、21、21种风味物质。随着蒸煮时间的延长,马铃薯由开始的肉黄色逐渐变暗,且不良风味不断增强;使马铃薯产品具有香味的己醛、壬醛、反-2-辛烯醛、癸醛、反,反-2,4-庚二烯醛、反-2-壬烯醛、反,反-2,4-壬二烯醛、反,反-2,4-癸二烯醛等物质含量逐渐降低。随蒸煮时间延长,马铃薯的特征风味物质甲硫基丙醛含量没有显著变化,此外,受其他关键风味物质减少的影响,甲硫基丙醛增加了马铃薯产品整体风味的刺激性。     

Fruit and Vegetable Waste: Bioactive Compounds,Their Extraction,and Possible Utilization

Fruits and vegetables are the most utilized commodities among all horticultural crops. They are consumed raw, minimally processed, as well as processed, due to their nutrients and health‐promoting compounds. With the growing population and changing diet habits, the production and processing of horticultural crops, especially fruits and vegetables, have increased very significantly to fulfill the increasing demands. Significant losses and waste in the fresh and processing industries are becoming a serious nutritional, economical, and environmental problem. For example, the United Nations Food and Agriculture Organization (FAO) has estimated that losses and waste in fruits and vegetables are the highest among all types of foods, and may reach up to 60%. The processing operations of fruits and vegetables produce significant wastes of by‐products, which constitute about 25% to 30% of a whole commodity group. The waste is composed mainly of seed, skin, rind, and pomace, containing good sources of potentially valuable bioactive compounds, such as carotenoids, polyphenols, dietary fibers, vitamins, enzymes, and oils, among others. These phytochemicals can be utilized in different industries including the food industry, for the development of functional or enriched foods, the health industry for medicines and pharmaceuticals, and the textile industry, among others. The use of waste for the production of various crucial bioactive components is an important step toward sustainable development. This review describes the types and nature of the waste that originates from fruits and vegetables, the bioactive components in the waste, their extraction techniques, and the potential utilization of the obtained bioactive compounds.     

Benzoic acid and its derivatives as naturally occurring compounds in foods and as additives: Uses,exposure, and controversy

Benzoic acid is an aromatic carboxylic acid naturally present in plant and animal tissues, which can also be produced by microorganisms. Benzoic acid and a wide range of derivatives and related benzenic compounds, such as salts, alkyl esters, parabens, benzyl alcohol, benzaldehyde, and benzoyl peroxide, are commonly used as antibacterial and antifungal preservatives and as flavoring agents in food, cosmetic, hygiene, and pharmaceutical products. As a result of their widespread occurrence, production, and uses, these compounds are largely distributed in the environment and found in water, soil, and air. Consequently, human exposure to them can be high, common, and lengthy. This review is mainly focused on the presence and use of benzoic acid in foods but it also covers the occurrence, uses, human exposure, metabolism, toxicology, analytical methods for detection, and legal limits for benzoic acid and its derivatives. Their controversial effects and potential public health concerns are discussed.