Aphid-resistant Transgenic Tobacco Plants Expressing Modified gna Gene

A gene sequence coding for the precursor of Galanthus nivalis agglutinin (GNA) was modified by site-directed mutagenesis to change very low usage bias codons to higher usage bias ones for improvement of the gene expression in transgenic tobacco (Nicotiana tabacum L.) plants. Results from Western blot analysis of some of the transgenic tobacco plants showed that the expression level of GNA in plants transformed with the modified gene GNA34m reached 0.25% of total soluble proteins, while that of the GNA34 gene transgenic plants was 0.17%. Since the GNA expression level increased, the aphid resistance of GNA34m transgenic plants were also enhanced significantly as judged by a 71.0% aphid population inhibition in insect bioassay of GNA34m transformed plants and 63.7% for the plants transformed with the natural GNA34 gene.

Cloning of Promoter of Chinese Bean GRP 1.8 Gene and Characterization of Its Function in Transgenic Tobacco Plants

In order to learn the expression pattern of GRP1 8(glycine rich protein) gene promoter in transgenic plants and to explore its potential application in plant genetic engineering for vascular specific expression of interested genes, GRP 1 8 promoter was amplified by PCR from Chinese bean genomic DNA. The intermediate vector was constructed by inserting vascular specific expression promoter of GRP 1 8 gene in vector pBI 101. The regenerated tobacco plants obtained were analyzed by PCR to select the putative transgenic plants. The histochemical localization of GUS( β D glucosidase) activity indicates that as for that of GRP 1 8 promoter we can confer the vascular specific expression of GUS gene.

Drought tolerance evaluation of tobacco plants transformed with different set of genes under laboratory and field conditions

Although extensive studies have demonstrated that many drought-responsive genes confer drought toler- ance to plants, comparisons of the drought tolerance capa- bilities conferred by different genes under various natural conditions have seldom been reported. We evaluated and compared the effects of two sets of transgenes, the drought- responsive genes （AtDREBIB and AtCBL1） and the root architecture-regulated genes （iaaM and AtCKX）, on drought tolerance in Nicotiana tabacum plants subjected to different conditions. The expression of AtCKX3 driven by a root- specific promoter PYKIO （designated hereafter as PIO; PIO：AtCKX3）, 35S：AtCKX3, or PlO：iaaM promoted root growth and development. Compared to plants harboring PIO：AtCKX3, 35S：AtCKX3, PlO：iaaM, or the empty vector, those carrying 35S：AtDREB1B, 35S：AtCBLl, or 35S：iaaM exhibited increased drought tolerance under laboratory- controlled conditions. Conversely, in field conditions, plants transformed with 35S：AtDREB1, 35S：AtCBL1, or 35S：iaaM were sensitive to drought stress. Under field conditions, drought stress dramatically reduced the growth and seed production of plants harboring 35S：AtDREBIB, 35S：A tCBL1, 35S：iaaM, or the empty vector, whereas it had little effect on plants carrying PIO：AtCKX3, 35S：AtCKX3, or PlO：iaaM. This study demonstrates that a plant＇s tolerance to drought stress changes with environmental conditions, and our results indicates that manipulating the expression of genes that control root architecture may be important for engineering plants with improved drought tolerance in natural conditions.

Expression of a Tobacco Glycosyltransferase Gene Driving Promoter in Transgenic Tobacco

[Objective]The study was to analyze the expression of the deletion fragments from the promoter of a glycosyltransferase gene induced both by MeJA and SA cloned from tobacco W38（sm-Ngt） in transgenic tobacco plants.[Method]Using T1 seedlings of sm-Ngt transgenic tobacco lines containing Gus gene controlled by five 5＇ flank deletion promoter fragments different in length as experimental materials,GUS histochemical staining and fluorometric analysis of T1 seedlings treated with MeJA and SA for 16 h were conducted to analyze the effect of MeJA and SA treatment on the expression of 5＇ flank deletion promoter fragments.[Result]Of five 5＇ flank deletion promoter fragments transgenic plant lines,30 d old T1 seedlings containing 220-0 bp promoter fragment performed worst in GUS staining（showing least staining spots）,those containing-524-0 bp and-468-0 bp promoter fragment both performed best.In the plants not treated with MeJA and SA,activities of GUS driven by-524-0 bp and-468-0 bp deletion promoter fragments were enormously higher than that driven by-1 150-0,-800-0 or-220 0 bp,and which were proved to be not resulted from insert copy number by Southern blot.For GUS expression,promoter fragment-800-0 bp expression was doubly induced by both MeJA and SA,while fragment-1 150-0 was induced by MeJA.[Conclusion]There are activity enhancement elements within-524--220 bp of the sm-Ngt in promoter and activity down regulation elements within-1 150--524 bp region,as well as MeJA and SA doubly inducing activity regulation elements in this promoter.

Suitable Region for Flue-cured Tobacco (Nicotiana glauca L.) Planting Based on Spatial Scene Similarity

[Objective] The aim was to establish a model based on spatial scene similarity, for which soil, slope, transport, water conservancy, light, social economic factors in suitable planting areas were all considered. A new suitable planting area of flue-cured tobacco was determined by comparison and analysis, with consideration of excellent area. [Method] Totaling thirty natural factors were chosen, which were clas- sified into nine categories, from Longpeng Town （LP） and Shaochong Town （SC） in Shiping County in Honghe Hani and Yi Autonomous Prefecture. [Result] According to weights, the factors from high to low were as follows： soil〉light〉elevation〉slope〉 water conservancy〉transport〉baking facility〉planting plans over the years〉others. The similarity of geographical conditions in the area was 0.894 3, which indicated that the planting conditions in the two regions are similar. If farmer population in unit area, farmland quantity for individual farmer, labors in every household, activity in planting flue-cured tobacco and work of local instructor were considered, the weights of different factors were as follows： farmer population in unit area〉farmland quantity for individual farmer〉farmers＇ activity in planting flue-cured tobacco〉educational back- ground〉labor force in every household〉instructor〉population of farmers＇ children at- tending school. The similarity of geographical conditions was 0.703 1, which indicated that it is none-natural factors that influence yield and quality of flue-cured tobacco. [Conclusion] According to analysis on suitable planting area of flue-cured tobacco based on assessment of spatial scene similarity, similarity of growing conditions in two spatial scenes can be analyzed and evaluated, which would promote further exploration on, influencing factors and effects on tobacco production.

Analysis on the Main Nutrient State of Tobacco Planting Soil in Fuquan City

[Objective] The research aimed to provide the reference for the precise formula and balanced fertilization of tobacco production in Fuquan City, Guizhou Province. [Method] 180 soil samples were gathered from Fuquan City by Global Position System （GPS） fixed position. The main nutrient contents and pH value were analyzed. [Result] The average contents of organic matter, available nitrogen, available phosphorus, available potassium in tobacco planting soil were 26.8 g/kg, 134.1 mg/kg, 35.9 mg/kg, and 222.1 mg/kg respectively, and the coefficient of vari- ation were 25.8%, 21.4%, 72.1%, and 55.3% respectively. The pH value of tobacco planting soil was 6.2, and the pH value coefficient of variation was 15.3%. [Conclu. sien] The organic matter, available nitrogen, available phosphorus, available potassi- um contents were abundant in the mass, but there were big difference among dif- ferent towns. The precise fertility types and precise fertility dosage should be deter- mined according to the main nutdent state and pH value of tobacco planting soil in Fuquan city.

Changes of Soil nutrients and Tobacco Quality in Linli County and Some Suggestions on Fertilization

In order to find out the main nutrient content of tobacco planting soil and the changing characteristics of tobacco quality in Linli County,the sampling survey data of tobacco planting soil samples in Linli in 2000 and 2015,and the main chemical components,appearances and sensory qualities and physical indexes of B2F and C3F tobacco leaves from 2000 to 2015 were comprehensively analyzed and evaluated.The results showed that:the available phosphorus increased by 6.10%per year and the pH value of tobacco planting soil increased in a small range year by year,the organic matter content decreased year by year,the alkali hydrolyzable nitrogen showed a downward trend,and the water-soluble chlorine showed a rapid downward trend;the soil fertility index(SFI)was at the"high"level;in 2000—2015,the quality of tobacco leaf was relatively stable and the quality was good.In Linli tobacco planting area,the application of nitrogen control,phosphorus reduction and chlorine supplement and increase of organic matter could help us achieve the goal of high quality and efficiency of tobacco production.

Risk Regionalization of Low-temperature Disasters for Flue-cured Tobacco Planting in Qujing Area Based on GIS

There is a prominent,complex and diverse three-dimensional climate and a variety of meteorological disasters in Qujing area. The risk zoning of low-temperature disasters for flue-cured tobacco planting in Qujing area was studied to provide reference for drawing on advantages and avoiding disadvantages in flue-cured tobacco planting,disaster reduction,and disaster relief services. According to the production practice of fluecured tobacco and local climate analysis,it was determined that flue-cured tobacco in Qujing area was very vulnerable to low temperature during the seedling stage（ from early February to middle April） and in the mature period（ from early July to early September）. Based on the quantitative analysis and evaluation of risk of disaster-causing factors,sensitivity of disaster-breeding environment,vulnerability of carriers,and disaster prevention and reduction capability,a risk assessment model of meteorological disasters was established to precisely evaluate and zone the risk of low-temperature disasters for flue-cured tobacco planting in allusion to the seedling and mature stage in Qujing area by using GIS technology. The risk of lowtemperature disasters for flue-cured tobacco planting during the two periods was divided into four grades,namely low,medium,high and very high risk.

The application of near-infrared spectra micro-image in the imaging analysis of biology samples

In this research,suitable imaging methods were used for acquiring single compound images ofbiology samples of chicken pectorales tissue section,tobacco dry leaf,fresh leaf and plantglandular hair,respectively.The adverse effects caused by the high water content and thethermal effect of near infrared(NIR)light were effectively solved during the experiment procedures and the data procesing.PCA algorithm was applied to the NIR micro-image of chickenpectorales tissue.Comparing the loading vector of PC3 with the NIR spectrum of dry albumen,the information of PC3 was confimmed to be provided mainly by protein,i.e.,the 3rd score imagerepresents the distribution trend of protein mainly.PCA algorithm was applied to the NIR micro-image of tobacco dry leaf.The information of PC2 was confimed to be provided by carbohydrateindluding starch mainly.Compared to the 2nd score image of tobacco dry leaf,the comparedcorelation image with the reference spectrum of starch had the same distribution trend as the 2nd score image.The comparative correla tion images with the reference spectra of protein,glucose,fructose and the total plant alkaloid were acquired to confirm the distribution trend ofthese compounds in tobacco dry leaf respectively.Comparative correlation images of fresh leafwith the reference spectra of protein,starch,fructose,ghucose and water were acquired to confim the distribution trend of these compounds in fresh leaf.Chemimap imaging of plant glandularhair was acquired to show the tubular structure clearly.

Effect of cDNA fragments in different length derived from Potato Virus Y coat protein gene on the induction of RNA-mediated virus resistance

We have reported that cDNA derived from entire coat protein (CP) gene of potato virus Y (PVY) could induce resistance to PVY infection in transgenic tobacco plants, and the resistance was further demonstrated to be RNA-mediated rather than coat protein-mediated. In this study, we cloned cDNA fragments of 202 bp, 417 bp, and 603 bp in length derived from the 3′ end of the PVY CP gene, and the cDNA fragments were introduced into tobacco (var. NC89) plants via Agrobacterium-mediated transformation system. The results of resistance assay showed that the CP cDNA fragments of 417 bp and 603 bp could confer resistance of the trans-genic plants to PVY infection, but the fragment of 202 bp in length could not. Molecular analysis revealed that the resistance was RNA-mediated, which is believed to be a result of post-transcriptional gene silencing. The results indicate that the length of cDNA fragments needed for resistance induction was located somewhere between 202 bp and 417 bp from the 3′ end of PVY CP gene.

Piriformospora indica confers cadmium tolerance in Nicotiana tabacum

Piriformospora indica, a root-colonizing endophytic fungus of Sebacinales, promotes plant growth and confers resistance against biotic and abiotic stresses. In order to confirm the influence of P. indica on growth, proline, malondialdehyde（MDA）, chlorophyll, and cadmium（Cd） amounts in Nicotiana tabacum under Cd stress, hydroponics, pot and field trials were conducted. The results showed that P. indica can store Cd in plant roots and reduce leaf Cd content, reduce the concentration of MDA, and increase the proline and chlorophyll content and the activities of catalase, peroxidase, and superoxide dismutase under hydroponic Cd stress. RT-PCR analysis showed that the relative expression level of genes Gsh2, Ta PCS1, oas1, GPX, and Hsp70 in colonized plants was 4.3, 1.4, 2.9, 1.7, and 6.9fold higher than in un-colonized plants respectively. Cd exposure significantly reduced un-colonized plants＇ agronomic traits compared to P. indica-colonized ones. Our results suggested that P. indica can sequester Cd in roots, so that much less cadmium was transported to leaves, and the increased concentrations of antioxidant enzymes, pigments and proline contents, as well as the higher expression of stress-related phytochelatin biosynthesis genes in P. indica-inoculated plants, may also serve to protect N. tabacum plants against oxidative damage, enhancing Cd tolerance.