Nonphytotoxic copper oxide nanoparticles are powerful“nanoweapons”that trigger resistance in tobacco against the soil-borne fungal pathogen Phytophthora nicotianae

Investigations into the potential application of nanoparticles acting as nanofungicides in sustainable agriculture are rapidly expanding due to the high antimicrobial properties of these compounds,which do not risk inducing pathogen resistance to fungicides.A detailed understanding of the impact of copper oxide nanoparticles(CuO NPs)on soil-borne phytopathogenic fungi is yet to be obtained.This study aimed to explore the in vitro antifungal activity and control efficacy of CuO NPs applied via irrigation with respect to tobacco black shank(TBS)disease caused by Phytophthora nicotianae.The results revealed that CuO NPs greatly interfered with the reproductive growth process of this fungus,repressing hyphal growth,spore germination and sporangium production.Additionally,morphological damage,intracellular ROS accumulation and increased SOD enzyme activity in hyphae were the antifungicidal mechanisms of these NPs.In pot experiments,treatment with CuO NPs at 100 mg L^(–1)significantly suppressed TBS development,compared with the effect on control plants,and the control efficacy reached 33.69%without inducing phytotoxicity.Exposure to CuO NPs significantly activated a series of defense enzymes,and resistance genes in tobacco can further explain the mechanisms by which CuO NPs suppressed fungal infection.The Cu content in both the leaves and roots of P.nicotianae-infested plants increased by 50.03 and 27.25%,respectively,after treatment with 100 mg L^(–1)CuO NPs,compared with that of healthy plants.In particular,a higher Cu content was observed in infected roots than in leaves.Therefore,this study showed the potential of CuO NPs applied as nanofungicides and as nanoinducers of fungus resistance genes for the management of TBS through inhibition of pathogen infection and stimulation of plant defenses.

Effect of Nitrogen Fertilization on Growth and Photosynthetic Nitrogen use Efficiency in Tobacco （Nicotiana tabacum L.）

Soil pot experiments were conducted in a greenhouse to examine the effects of different nitrogen （N） supply （low, 0.15 g N/kg; middle, 0.3 g N/kg; and high, 0.6 g N/kg dry soil） on the growth, photosynthetic characteristics and photosynthetic nitrogen use efficiency （PNUE） of tobacco seedlings （Nicotiana tabacum L. Yunyan 87）. The results showed middle and high N significantly enhanced seedling growth including plant stem and leaf dry weight comparing with low N. High N supply could lead to a dramatic increase in the photosynthetic capacity of tobacco seedlings under low N conditions. There were significant differences in leaf N content between nitrogen treatments. About a 76% increase in leafN content in plants fed by high N resulted in about 43% increase in Rubisco content and 27% in net photosynthetic rate. The non-corresponding increases in photosynthetic rate in tobacco seedlings fed by high N relative to low N resulted from Rubisco activity and/or carboxylation efficiency （CE）. These results indicated that tobacco seedlings under high N application can maintain high net photosynthetic rate （Pn） but lower PNUE, will finally result in a decline in N use efficiency.

Cloning and Expression of Calcium-Dependent Protein Kinase (CDPK) Gene Family in Common Tobacco (Nicotiana tabacum)

To further study the function of calcium-dependent protein kinase （CDPK） gene family in common tobacco （Nicotiana tabacum）, it is necessary to isolate more CDPKs from common tobacco and describe the sequence characteristics, evolutionary relationship and gene expression. Reverse transcription-PCR （RT-PCR）, rapid amplification of cDNA （RACE） and bioinformatics methods were used to isolate CDPKs from common tobacco. A phylogenetic tree was created using the MEGA4.0 program and expression patterns of the three full-length CDPK genes were studied by RT-PCR. After all aforementioned efforts, we obtained eight additional common tobacco CDPK genes, of which three possessed complete open reading frames （ORFs）. Phylogenetic analysis divided 1 1 full-length Nicotiana CDPK genes into four subfamilies, and two putative common tobacco and Arabidopsis orthologous CDPK genes might correspond to well-conserved functions. Three full-length CDPK genes in common tobacco were detected in all tobacco organs tested, but their expression patterns were significantly different. Eight non-redundant common tobacco CDPK genes were isolated in this study. Along with the previously characterized CDPK genes, at least 15 members of the CDPK family exist in common tobacco. This work establishes a foundation for a genome-wide study of this important gene family in common tobacco.

A TOM1 homologue is required for multiplication of Tobacco mosaic virus in Nicotiana benthamiana

The AtTOM1 gene of Arabidopsis thaliana had been shown to be essential for the efficient multiplication of Tobacco mosaic virus(TMV) in A.thaliana.In this study,we cloned an AtTOM1-like gene from Nicotiana benthamiana named as NbTOM1.Sequence alignment showed that NbTOM1 is closely related to AtTOM1 homologues of N.tabacum and Lycopersicon esculentum with 97.2% and 92.6% nucleotide sequence identities,respectively.Silencing of NbTOM1 by a modified viral satellite DNA-based vector resulted in complete inhibition of the multiplication of TMV in N.benthamiana.The result suggests that inhibition of NbTOM1 via RNA silencing is a potentially useful method for generating TMV-resistant plants.

Cloning of Salt Stress Responsive cDNA from Wheat and Resistant Analysis of Differential Fragment SR07 in Transgenic Tobacco

Analysis of the gene expression differentiation in leaves of wheat （Triticum aestivum L.） cultivar Baofeng 7228, under salt stress, was carried out by Differential-Display Reverse Transcription-polymerase Chain Reaction （DDRT-PCR.） Twenty-seven differential cDNA fragments were obtained. The expression of the SR07 fragment was induced noticeably by salt treatment, and the nucleotide sequence homology of 87% between the SR07 fragment and PIPs （water channel proteins） was observed. Further research showed that a 561 bp open read frame was present in the SR07 fragment. Plant expression vector of pCAMBIA-SR07 was constructed and three transformants of tobacco （Nicotiana tobacum） mediated by Agrobacterium tumefaciens plasmid were obtained. Resistance to salt, PEG, and mannitol stresses of the three transformants were examined. No significant difference （P 〉 0.05） was observed between the control and the transformants in resistance to salt stress, but there was significant difference （P 〈 0.05） between the control and the transformants in resistance to PEG and mannitol stresses. Therefore, the expression of the SR07 fragment may play an important role in the water regulation of the plant.

以单细胞压片技术观察烟草(Nicotiana tabacum L.)合子细胞器DNA的分布

通过实验建立了单个合子的压片技术,尝试了将染色与固定分开或同时进行的两种压片方法,两种方法均可以用于不同发育阶段合子细胞器DNA分布的检测,但二者各具特色。同时也利用共聚焦激光扫描显微镜观察了烟草(NicotianatabacumL.)合子细胞器的分布,并与单细胞压片技术进行了比较。实验表明它们各有其优越性。

烟草Nicotiana glauca遗传瘤的诱导

以往的研究证明一些烟草杂种能自发形成遗传瘤,而正常条件下杂交亲本各自本身并不能自发形成遗传瘤。该研究首次从烟草Nicotiana glauca品种中诱导产生出遗传瘤,这些N.glauca遗传瘤与杂种N.glauca×N.langsdorffii遗传瘤具有相同的特征,即在无激素的培养基上能正常分化、对外源植物激素不敏感等特点。该研究结果同时还进一步证明种间杂交并不是诱导烟草产生遗传瘤的唯一因素。

Quality Characteristics of Tobacco Leaves with Different Aromatic Styles from Guizhou Province,China

The relationships between chemical components and quality indexes were studied in the tobacco leaves with different aromatic styles. A total of 16 chemical components, 4 quality indexes, and 6 smoking quality indexes from 366 tobacco leaf samples with 4 different types of aroma from Guizhou Province, China, were subjected to principal component analysis and stepwise regression analysis. The tobacco leaves with different types of aroma showed remarkable difference in the contents of chemical components, quality indexes, and smoking quality indexes. The first principal factors （carbohydrates and nitrogen-containing compounds） of the chemical composition of the leaf were similar among different types of aroma, which showed that the quality of the leaf was mainly influenced by carbohydrates and nitrogen-containing compounds and their ratios. The factors for the second through the seventh principal components varied largely among varioUs aromatic types, suggesting the contribution of other chemical components to the leaf quality. In addition, the smoking quality of four different aromatic leaves showed significant correlation with the different chemical components. The quality of tobacco leaves with different types of aroma was influenced by multiple factors, especially ecological conditions and culture techniques, which may provide guidance for directive cultivation of high-quality tobacco leaves.

Changes of Polyphenols in Tobacco Leaves During the Flue-Curing Process and Correlation Analysis on Some Chemical Components

The changes of polyphenols in tobacco leaves during the flue-curing process and correlation analysis on some chemical components were studied. Leaf samples were taken from different tobacco-producing regions in Henan Province, China. The results indicated that the content of total phenols increased during the first 24 h of curing, and then decreased. It reached the lowest value at 72 h of curing and increased rapidly after that. The content of chlorogenic acid also increased during 0-24 h of curing. But the lowest point occurred at 60 or 72 h of curing and then it increased till the end of the curing process. The content of mtin generally increased with curing, and showed little fluctuations. The changes of PPO and POD activity were the opposite. Rutin was found to have a highly significant positive correlation with total sugar （r=0.822^＊＊）, but a highly significant negative correlation with starch, nicotine, and protein.

Interference of Quinolinate Phosphoribosyltransferase Gene QPT Affects Agronomic Traits and Leaf Quality in Nicotiana tabacum L.

Quinolinate phosphoribosyltransferase(QPRTase),a key enzyme in ensuring nicotinic acid is available for the synthesis of defensive pyridine alkaloids in Nicotiana species,also plays an important role in nicotinamide adenine dinucleotide(NAD)biosynthesis.In this study,the morphological traits,the quality characteristics and photosynthetic parameters in QPT-overexpressing/interfering tobacco plants were investigated,respectively.Results showed that the interference of QPT gene not only reduced significantly the morphological traits including plant height,stem girth,leaf number and leaf length,etc.at 20 days after transplanting(DAT),but the flowering period was delayed 10-15 d in interfered tobaccos compared with the overexpressed,control and wild-type counterparts.However,at 40 DAT and 60 DAT,only three indexes(plant height,stem girth and leaf number)in QPT-interfering plants appeared significant difference in comparison with other three types of tobacco lines.Meanwhile,the determination results from nicotine,sugar,K+and Cl-content showed the nicotine content in interfered plants was always significantly lower than that in overexpressed plants,control and the wild-type ones respectively whatever toppling or not.At the same time,the toppling treatment also caused the increasement of K+content among the four different tobacco lines,but the maximum increase amplitude of K+content was found in QPT-overexpressing tobaccos while the minimum appeared in QPT-interfering plants.Finally,QPT-interference in transgenic tobaccos likewise affected the photosynthesis by reducing net photosynthetic rate(Pn),stomata conductance(Gs)and transpiration rate(Tr),while there was no significant difference between QPT-overexpressing plants and the controls and the wild-types.

Populational Fluctuation and Distribution of Epitrix spp.Foudras(Coleoptera:Chrysomelidae)in the Organic Tobacco Management in Santa Cruz do Sul,RS,Brazil

Among the chrysomelids, some species are considered agricultural pests, such as some representatives of Epitrix spp. Popularly known as tobacco flea, these beetles cause damage to tobacco (Nicotiana tabacum L.) by feeding on the leaf surface, causing injuries, reducing productivity and the final quality of the product to be marketed. However, studies of the biology and interactions of these individuals with the environment become essential in order to develop effective and sustainable control measures. The objective of this study was to analyze the distribution and population fluctuation of Epitrix spp., as well as to evaluate the possible influence of temperature, rainfall and adjacent vegetation on the population dynamics of this beetle in organic tobacco growing in the municipality of Santa Cruz of the South, RS. The collections were carried out weekly during the 2011/2012 harvest, using Malaise and Pit-fall traps, distributed in four points along three lines. A total of 1584 individuals belonging to the genus Epitrix were collected, and their greatest abundance was observed in late January and early February 2012 due to climatic factors, such as rainfall and temperature, favorable to the development of specimens and the tobacco leaf harvesting reduced the availability of food and conditioned a greater movement of these individuals in the crop. The results presented here are of great importance for deciding the best methodology for controlling the smoke flea, as well as knowing the influence of abiotic factors on the behavior of these organisms in the field.

烤烟黑胫病抗性评价及生理响应特性分析

本研究旨在揭示不同烤烟品种对烟草黑胫病的抗性机理。通过对抗病性的鉴定,从24个烤烟品种(系)中鉴定出4个高抗品种、8个中抗品种、8个中感品种和4个高感品种。对这些品种在烟草疫霉(Phytophthora parasitica var.nicotianae)侵染后,从中选取2个高抗品种和2个高感品种测定其抗氧化酶系活性、水杨酸含量以及抗病相关基因的表达情况。结果表明,在受到病原菌侵染时,高抗品种的抗氧化酶活性显著高于高感品种,暗示着更强的氧化应激防御能力。此外,高抗品种中的内源水杨酸合成以及抗病相关基因的诱导表达均显著高于高感品种,表明这些品种能够更有效地激活其防御系统以应对烟草黑胫病菌的侵染。本研究结果为理解烤烟对黑胫病的抗性机制提供了重要信息,并为烟草抗病育种提供了理论依据。

基于电子鼻技术的烟丝受虫害前后挥发性成分差异分析

针对烟草(Nicotiana tabacum L.)中烟草甲(Lasioderma serricorne)检测技术不完善,检测结果不可靠等问题,以电子鼻检测结果为基础,通过主成分分析法(PCA)和Loading分析法对数据结果进行分析。结果表明,4种烟丝的主要挥发物质为硫类物质、短链烷烃、醇醚醛酮、小分子氮氧化合物等,虫样及性激素的主要挥发性物质是小分子氮氧化合物、硫化物。受虫害后烟丝中硫类化合物明显降低,在对无机硫化物敏感的传感器(W1W)中浓香虫害烟丝的响应值比浓香烟丝下降48.33%,清香虫害烟丝比清香烟丝下降59.48%;在对有机硫化物敏感的传感器(W2W)中浓香虫害烟丝的响应值比浓香烟丝下降35.72%,清香虫害烟丝比清香烟丝下降48.55%。PCA结果显示,4种烟丝样品表现出非常好的区分度,雌虫、雄虫样品在占比高达99.70%的主成分1上几乎没有差别。Loading分析结果显示,烟丝样品中气味主要成分为硫类物质,烟草甲虫样气味主要成分是小分子氮氧化物,其次为硫类物质。

土壤干旱条件下不同施钾水平对烟草光合速率和蒸腾效率的影响

研究了土壤干旱条件下 ,不同的施钾水平对烟草光合速率、胞间 CO2 浓度、气孔导度、蒸腾速率、蒸腾效率及生物量的影响。结果表明 :在土壤干旱条件下适量施钾可以减少叶肉细胞光合活性的下降 ,消弱非气孔因素对光合的限制 ,增强气孔调节能力 ,提高蒸腾效率 ,并获得较高的生物量。

干旱胁迫及不同钾水平下烟草叶肉细胞中钾的再分布

研究了干旱胁迫及不同水平下K+在烟草叶肉细胞的液泡、线粒体、叶绿体中的分布。结果表明,无论是正常水分条件下还是干旱胁迫下,施K肥可以提高叶肉组织中K的含量;烟草叶肉细胞中K+主要集中在液泡中,叶绿体中次之,线粒体中最少。干旱胁迫下,K+在烟草叶肉细胞内存在明显再分配现象,不施钾植株在干旱胁迫下液泡中K+总量变化不大,但所占比例减少;而线粒体、叶绿体中K+总量和所占比例均明显增加。施钾植株干旱胁迫下液泡中K+所占比例也有减少,但总量增加;线粒体中K+总量和所占比例均减少,叶绿体中K+总量和所占比例均明显增加,且叶绿体中K+的变化趋势随施钾量增加而增强。结果还表明,在不同干旱程度下,适量施钾可以减少烟草叶肉细胞光合活性的下降。

烟草黄酮醇合成酶基因的克隆及其序列分析

根据已知的黄酮醇合成酶cDNA保守序列设计引物,用RT-PCR技术从烟草叶片中扩增获得黄酮醇合成酶cDNA片段,再用RACE方法得到其两端序列。根据获得的序列,设计引物分离得到完整的1188bp的黄酮醇合成酶基因,其开放阅读框编码346个氨基酸。序列分析显示,烟草黄酮醇合成酶与高杯花、矮牵牛和马铃薯的同源性分别为87%、86%和84%,与其它物种中的同源性也在80%左右,表明不同物种中黄酮醇合成酶基因具有高度同源性。此外,在氨基酸水平上,该酶与其它依赖于2-酮戊二酸的双加氧酶及其相关酶也具有同源性。

干旱条件下不同施钾水平对烟草水分关系的影响

研究干旱胁迫及不同钾水平下烟草植株不同器官及叶肉细胞不同部位中钾的分布 ,探讨干旱条件下钾水平对烟草水分关系的影响及干旱下水分变化对钾的分布影响。结果表明 :在土壤干旱条件下钾在叶脉和叶肉间 ,叶肉细胞内液泡、线粒体、叶绿体之间有明显的再分配过程 ;不同施钾水平在烟草植株内钾含量的差异导致了含水量的差异 ;土壤干旱条件下施钾量增加能够明显提高烟叶含钾量 ,而使含水量维持较高水平 ;施钾可以提高叶片保水力 ,增强气孔的调节能力 。

不同有机酸对烤烟品质和产值的影响

采用大田试验研究了苹果酸、油酸和腐殖酸对烤烟品质指标及产值效果的影响。结果表明,3种有机酸能明显提高烟叶中P素、K素、总糖、还原糖含量、钾氯比和糖碱比值,以及糠醛、苯甲醛、茄酮、巨豆三烯酮和新植二烯等主要香气成分的含量,改善烟草的香吃味。同时不同程度地降低烟叶中N素、淀粉、蛋白质、烟碱和氯离子的含量,从而协调和平衡烟叶中的化学成分,改善烟叶的品质。其中,苹果酸的效果最佳,腐殖酸和油酸次之。苹果酸可明显提高烤烟的均价和上中等烟的比例,腐殖酸可明显提高烤烟的产量、产值及上中等烟的比例。

烟草根系形态发育模拟模型

在分析烟草根系生长发育规律的基础上,采用作物模拟技术,定量地描述了根系生长与环境之间的动态关系,建立了烟草根系形态发育的数学模型。根据“根箱法”测定的资料,确定了根系模型的相关参数;通过运行模型,以较少的参数实现了烟草根系数量、长度、根长指数和根长密度等指标的输出,为根系的研究提供了新的手段。利用2003年的试验资料对模型进行检验,结果表明,烟草根系一级、二级侧根根长及其数量、根长密度和根长指数等的模拟值与实测值均呈显著正相关,相关系数分别达0.9540～0.9896,表明模型对烟草根系形态发育动态具有较好的预测效果。