Growth Of Tobacco Research Articles

Influence of Glycylglycine, Glycine, and Glycylaspartic Acid on Growth, Development, and Gene Expression in a Tobacco (Nicotiana tabacum) Callus Culture

The dipeptides glycylglycine (GlyGly) and glycylaspartic acid (GlyAsp) and amino acid glycine (Gly) in a concentration of 10–7 M in a medium essentially stimulate the growth and development of tobacco (Nicotiana tabacum) calli. GlyGly, GlyAsp, and Gly influence the cell differentiation and tissue formation processes. They stimulate formation and growth of leaves and roots. After incubation of tobacco seedling roots in the presence of 10–5 M fluorescent FITC-labeled peptides or glycine, marked fluorescence was observed in cells of the root cap and epidermis. The fluorescence was detected in the cell walls, cytoplasm, and nuclei. Thus, the peptides used can penetrate into the plant cell and be located in the nucleus and other cell compartments. Therefore, they may potentially interact with different structures and components of the cytoplasm and nucleus including various proteins, RNAs, and DNA. The penetration and accumulation of peptides in cells are tissue specific. In the tobacco callus, peptides modulate expression of the KNOX and GRF family genes that are responsible for cell differentiation and code for transcription factors. Thus, the dipeptides GlyGly and GlyAsp and amino acid Gly have marked physiological activity and can be related to efficient plant growth regulators.

RNAi-mediated silencing of spermidine synthase generesults in reduced reproductive potential in tobacco.

Spermidine belongs to a class of polycationic compounds known as polyamines. Polyamines are known to be involved in a wide range of biological processes but the exact role and contribution of different polyamines to these processes are still not clear. In the present study, we have tried to understand the contribution of triamine spermidine to the growth and development of tobacco by downregulating spermidine synthase gene (SPDS) using RNA interference. Down-regulatioin of SPDS gene resulted in decreased spermidine levels and a slight increase in the levels of its precursor, the diamine putrescine and the molecule downstream of Spd, the tetraamine spermine. While the vegetative growth of the transgenics remained largely unaffected, SPDS down-regulation resulted in smaller size of flowers, decreased pollen viability and seed setting, and a reduced and delayed seed germination. When subjected to abiotic stress, the transgenics showed an increased tolerance to salinity and drought conditions owing to a steady intracellular pool of putrescine and spermine. The results not only highlight the importance of spermidine in determining reproductive potential in plants but have also help delineate its function from that of putrescine and spermine.

Metabolic profiling of tobacco leaves at different growth stages or different stalk positions by gas chromatography–mass spectrometry

The dynamic and temporal changes in tobacco leaf metabolites can have an immense impact on their compositions, which are closely related to the quality and flavor of the tobacco leaves. To investigate the dynamic changes in metabolites during tobacco growth and development and the diversity of metabolites in tobacco leaves from different stalk positions, a gas chromatography–mass spectrometry (GC–MS) method with derivatization was developed to profile tobacco leaves. A hierarchical cluster analysis (HCA) enabled the assignment of five types of tobacco leaves (the middle leaves in the resettling, vigorous, maturity stage and lower, and upper leaves in the maturity stage) to different groups. The differences among the samples at different growth stages are much more obvious than those from different sampling positions. Using the partial least squares-discriminant analysis (PLS-DA) model, the metabolites with distinct differences were screened out. During tobacco development, the contents of the metabolites related to sugar metabolism, amino acid metabolism, shikimic acid metabolism and terpenoid metabolism all increased at first and then decreased, while the contents of the tricarboxylic acid cycle intermediates, such as citric acid and fumaric acid, both decreased at first and then increased. The alkaloid contents increased significantly throughout the developmental period, and the metabolite contents related to organic acid decreased significantly during the maturity stage. Among the tobacco leaves from different stalk positions in the maturity stage, the sugar contents were highest in the middle leaves, while the organic acid contents were highest in the lower leaves. In addition, the nicotine, chlorogenic acid and α-4,8,13-duvatriene-1,3-diol contents were highest in the upper leaves. Apart from insights into the metabolite changes that occurred during tobacco leaf development, these results also provide potentially valuable information for regulating the primary metabolites in the future.

Genome-wide identification, evolution and expression analysis of cyclic nucleotide-gated channels in tobacco (Nicotiana tabacum L.)

Tobacco (Nicotiana tabacum) serve as the top leading commercial, non-food, and model crop worldwide. Cyclic nucleotide-gated channels (CNGCs) are ligand-gated, calcium-permeable, divalent, cation-selective channels, involved in important biological functions. Here, we systematically characterized thirty-five CNGC genes in the genome of Nicotiana tabacum, and classified into four phylogenetic groups. Evolutionary analysis showed that NtabCNGC family of N. tabacum originated from the parental genome of N. sylvestris and N. tomentosiformis, and further expanded via tandem and segmental duplication events. Tissue-specific expression analysis showed that twenty-three NtabCNGC genes are involved in the development of various tobacco tissues. Subsequent RT-qPCR analyses indicated that these genes are sensitive towards external abiotic and biotic stresses. Notable performances were exhibited by group-I and IV CNGC genes against black shank, Cucumber mosaic virus, Potato virus Y, cold, drought, and cadmium stresses. Our analyses also suggested that NtabCNGCs can be regulated by phosphorylation and miRNAs, and multiple light, temperature, and pathogen-responsive cis-acting regulatory elements present in promotors. These results will be useful for elaborating the biological roles of NtabCNGCs in tobacco growth and development.

Effects of different growth temperatures on growth, development, and plastid pigments metabolism of tobacco (Nicotiana tabacum L.) plants

BackgroundTemperature remarkably affects the growth and metabolism of plants. Tobacco is an important cash crop, and the long-term effects of different growth temperatures (18.5, 23.5 and 28.5 °C, daily average) on growth, development and plastid pigments metabolism of tobacco plants were investigated in this study.ResultsCompared with tobacco plants grown under 23.5 °C, treatments with 18.5 and 28.5 °C inhibited the expansion of leaves. The contents of superoxide anion (O2·−), hydrogen peroxide (H2O2) and malonaldehyde (MDA) in the leaves were significantly increased under 28.5 °C from 0 to 60 days, which in turn accelerated the flowering and senescence of tobacco plants. By contrast, the treatment with 18.5 °C remarkably decreased O2.−, H2O2 and MDA, and delayed the flowering and senescence. Furthermore, treatment with 18.5 °C significantly up-regulated the expression of glutamyl-tRNA reductase (Glu-TR) and magnesium chelatase (MgCH), and down-regulated the ferri chelatase (FeCH), protochlorophyllide oxidoreductase, chlorophyllase (CHLase), phaeophorbide a monooxygenase (PaO) and phytoene synthase (PSY), which further promoted the accumulation of chlorophyll (Chls) and reduced the carotenoids (Cars) in leaves. On the contrary, exposing to 28.5 °C remarkably down-regulated the Glu-TR and MgCH, and up-regulated the FeCH, CHLase, PaO and PSY, which in turn decreased the Chls and increased the Cars in tobacco leaves.ConclusionAs compared with the plants grown under 23.5 °C, lower (18.5 °C) and higher (28.5 °C) growth temperature inhibited the growth of tobacco plants. In general, treatment with 28.5 °C accelerated the flowering and senescence of tobacco plants by enhancing the accumulation of O2.− and H2O2 in leaves, while exposing to 18.5 °C had the opposite effects. Treatment with 18.5 °C increased the content of Chls and reduced the Cars in leaves. In contrast, Treatment with 28.5 °C decreased the Chls and increased the Cars. Moreover, both O2.− and H2O2 took part in the breakdown of Chls in tobacco leaves to some extent. The results suggest that growth temperature could regulate growth, development, and plastid pigments metabolism, and 23.5 °C could be an optimal temperature for growth, development and metabolism of plastid pigments of tobacco plants under the experimental conditions.

Financial consequences from smoking-related diseases in middle-income countries: Evidence and lessons from Mexico.

SummaryMiddle‐income countries are experiencing a significant growth of tobacco consumption‐related diseases, while their health systems lack the financial capacity to face them. Existing studies provide a general economic measurement of the problem but give no detailed evidence on the actual financial needs. The aim of this study was to measure the health care costs and financial consequences of the epidemiological changes related to tobacco consumption. A time‐series analysis for 2000 to 2016 was carried out in a national reference hospital in Mexico. We developed probabilistic models following the Box‐Jenkins methodology to forecast the expected changes in the epidemiologic profile and the health care services required for selected interventions. Health care costs were estimated following the instrumentation methods and validated with consensus technique. Comparing the epidemiological and economic burden in 2017 vs. 2019, there is a 20% to 90% increase in expected cases depending of the disease (p < .001) and a 25% to 93% increase in financial requirements (p < .001). Our data suggest that changes in the number of expected cases during the study period highlight the process of internal competition and add an element of intrinsic competition in the financial management of preventive and curative interventions.

Effects of CeCl3 and LaCl3 on callus and root induction and the physical response of tobacco tissue culture

La3+ and Ce3+ have positive effects on plant growth and production. Although it is well known that rare earth elements promote cell growth, the biological effects of La3+ and Ce3+ on callus, shoot and root induction in tobacco are still unclear. The relationships among callus induction, rooting, enzyme activities and stomatal characteristics in tobacco are unknown. The objectives of this study were to identify the relationships between the induction of calluses, shoots, roots, stomata and enzyme activities. The induction percentages of calluses, buds, roots were recorded at 5, 10, 15, 20 and 25 days after La3+ and Ce3+ treatments. Peroxidase isoenzyme activity was determined by electrophoresis. The characteristics of the stomata were observed under an optical microscope. Our results show that low concentrations of Ce3+ (<15 mg/L) result in increases in the induction percentages of calluses, buds and roots, but La3+ (>5 mg/L) inhibits the induction of calluses, buds and roots. There are more peroxidase isoenzyme bands in Ce3+ treatments than in La3+ treatments. This is consistent with the induction percentages of calluses, buds and roots in Ce3+ and La3+ treatments. High enzyme activities may promote the induction of calluses, buds and roots. The stomata area and stomata number of leaves are significantly different between La3+ treatments and Ce3+ treatments. La3+ improves the stomata area and number. Based on these results, we speculate that La3+ may promote the development of the photosynthetic system. Ce3+ may promote tobacco growth and rooting by improving enzyme activities.

Exogenous application of phenylacetic acid promotes root hair growth and induces the systemic resistance of tobacco against bacterial soft-rot pathogen Pectobacterium carotovorum subsp. carotovorum.

Phenylacetic acid (PAA) was evaluated for its capability to promote plant growth and induce systemic resistance in tobacco (Nicotianum tabacum L cv. Xanthi) against the bacterial soft rot pathogen Pectobacterium carotovorum subsp. carotovorum (PCC). Exogenous application of PAA influenced root formation, the activities of defence-related enzymes and the expression of defence and growth-related genes. Increased formation of lateral roots can be observed in tobacco treated with higher PAA concentrations. The highest elicitation of induced systemic resistance (ISR) was found in plants treated with 0.5mM PAA, where the phytotoxic effect was minimal. The activities of the defence enzymes phenylalanine ammonia-lyase (PAL), peroxidase (POD) and polyphnenoloxidase (PPO) were modulated upon treatment with different PAA concentrations. Reverse transcription-PCR analyses showed that 0.5mM PAA modulated the expression of the growth-related genes NtEXP2 and NtEXP6, and the defence-related genes Coi1, NPR1, PR-1a and PR-1b. These results showed that different concentrations of PAA can elicit different responses and effects on tobacco growth and resistance. This study presents the important role of PAA not only on plant growth but also for plant immunity against phytopathogens.

Screening and Application of Phthalic Acid Degrading Bacteria

O-phthalic acid is a kind of important pollutant, which accumulates in the environment with the extensive use of plastics and other products. Meanwhile, phthalic acid is one of the high content of allelopathic autotoxic substances secreted by tobacco. The accumulation of phthalic acid in soil is an important cause of tobacco continuous cropping effect. In order to degrade phthalic acid accumulated in environment, the barrier effect of tobacco continuous cropping caused by phthalic acid accumulation in soil can be removed. A strain capable of degrading phthalic acid was isolated from sludge of sewage treatment plant and compared with 16 s DNA. The homology between this strain and Enterobacter sp. is 99%. The optimum growth conditions are as follows: pH7 at 30°C, 500 mg/L of o-phthalic acid, inoculation concentration ≥ 1.2% and its highest degradation rate of o-phthalic acid is 74%. The results of pot experiment showed that the degradation efficiency of o-phthalic acid in soil was about 40%, which alleviated the inhibitory effect of o-phthalic acid accumulation on tobacco growth.

Impact of plant growth-promoting rhizobacteria on yield and disease control of Nicotiana tabacum

An unexplored soil microbial community associated with the root system of Nicotiana tabacum was isolated to analyze its impact on growth and yield of the crop. A total of nine isolates out of 180 were biochemically screened and characterized as potential plant growth-promoting rhizobacteria due to the expression of growth-promoting traits. All isolates were positive for ammonia production, 8 were positive for phosphate solubilization but none for auxin production. The majority of the isolates were also found positive for hydrogen cyanide, siderophore and hydrolytic/degradative enzymes production, enabling them to restrict the growth of Fusarium oxysporum in an in vitro assay. Although all tested isolates enhanced tobacco growth significantly, Baj-ER-01 and CD-RS-03 were found to be the most promising in enhancing all aspects of growth. This study provides evidence for the enhancement of growth and yield of inoculated tobacco plants through an adequate supply of nutrients and/or controlling phytopathogens.

Effect of Combined Application of Organic Fertilizer and Chemical Fertilizer in Different Ratios on Growth, Yield and Quality of Flue-cured Tobacco

Effect of Combined Application of Organic Fertilizer and Chemical Fertilizer in Different Ratios on Growth, Yield and Quality of Flue-cured Tobacco

Non-plastidial expression of a synthetic insect geranyl pyrophosphate synthase effectively increases tobacco plant biomass

Designing effective synthetic genes of interest is a fundamental step in plant synthetic biology for biomass. Geranyl pyrophosphate (diphosphate) synthase (GPPS) catalyzes a bottleneck step toward terpenoid metabolism. We previously designed and synthesized a plant (Arabidopsis thaliana)-insect (Myzus persicae, Mp) GPPS- human influenza hemagglutinin (HA) cDNA, namely PTP-MpGPPS-HA (or PTP-sMpGPPS-HA, s: synthetic), to localize the protein in plastids and improve plant biomass. To better understand the effects of different subcellular localizations on plant performance, herein we report PTP-sMpGPPS-HA re-design to synthesize a new MpGPPS-HA cDNA, namely sMpGPPS-HA, to express a non-plastidial sMpGPPS-HA protein. The sMpGPPS-HA cDNA driven by a 2 × S 35S promoter was introduced into Nicotiana tabacum Xanthi. PTP-MpGPPS-HA and PMDC84 vector transgenic plants were also generated as positive and negative controls, respectively. Eighteen to twenty transgenic T0 lines were generated for each sMpGPPS-HA, PTP-sMpGPPS-HA, and PMDC84. Transcriptional genotyping analysis demonstrated the expression of sMpGPPS-HA in transgenic plants. Confocal microscopy analysis of transgenic progeny demonstrated the non-plastidial localization of sMpGPPS-HA. Growth of T1 transgenic and wild-type control plants showed that the expression of sMpGPPS-HA effectively increased plant height by 50–80%, leaf numbers and sizes, and dry biomass by 60–80%. Calculation of the vegetative growth rates showed that the expression of sMpGPPS-HA increased plant height each week. Moreover, sMpGPPS-HA expression promoted early flowering and reduced leaf carotenoid levels. In conclusion, non-plastidial expression of the novel sMpGPPS-HA was effective for improving tobacco growth and biomass. Our data indicate that research examining different subcellular localizations facilitates a better understanding of in planta functions of proteins encoded by synthetic cDNAs.

Extremely low frequency electromagnetic field generator suitable for plant in vitro studies

The extremely low frequency electromagnetic field (ELF-EMF) occurs naturally from the earth and artificially as a human invention. The objectives of this study were to develop a suitable ELF-EMF generator for in vitro plants culture studies and to determine the effect of ELF-EMF exposure on in vitro tobacco (Nicotiana tabacum) growth and chlorophyll content. An ELF-EMF generator, the coGEM 1,000 was constructed using four coils of copper wires that were connected to a transformer, multimeter and rheostat. The coGEM 1,000 suitable for tissue culture plants is able to produce stable and uniform 6 and 12 mT 50Hz ELF-EMF in the four coils of the ELF-EMF generator. The tobacco in vitro plantlets were exposed to 6 and 12 mT of 50 Hz ELF-EMF for a period of 0.5, 1, 2 and 4 hours. The exposure to 12 mT ELF-EMF for an hour increased plant growth (shoot height); whereas the exposure to 6 mT Elf-EMF for an hour increased chlorophyll a, chlorophyll b and the total chlorophyll content.

Influence of high-carbon basal fertiliser on the structure and composition of a soil microbial community under tobacco cultivation

Soil microorganisms play a crucial role in cycling soil nutrients and providing organic nutrients for plant growth and development. Fertilisation balances soil fertility and quality, and affects soil microbial communities. Fertilisation is a frontier subject in agricultural and environmental sciences. Here we showed that the application of high-carbon basal fertiliser treatment could improve the tobacco yield and quality when compared to chemical fertiliser, high-carbon basal fertiliser and mixed high-carbon chemical fertiliser. The potential reason is that different fertiliser treatments influence soil fertility, such as nitrogen, phosphorus, and other contents, besides soil organic matter. Further experiments revealed that populations of bacteria, fungi and actinomycetes fluctuated during tobacco development under different fertilisation treatments. Then we performed high-throughput sequencing of the 16S rRNA gene, and the results showed that the fertilisation treatments had significant effects on the microbial community, particularly within the finer taxonomic divisions or non-dominant taxa. Moreover, proteobacteria and fungal genera had significantly different relative abundances during tobacco growth under various tobacco developmental stages and fertilisation treatments. These results indicated that mixed high-carbon chemical fertiliser could improve soil fertility by influencing the soil microorganism, and that the fertilisation treatments impacted on the structure and composition of the microbial community, and especially the diversity of non-dominant taxa. However, more studies are needed to confirm their reliability.

Physiological and proteomic analysis of plant growth enhancement by the rhizobacteria Bacillus sp. JS.

In this study, the effects of the plant growth-promoting rhizobacterium (PGPR), Bacillus sp. JS on the growth of tobacco (Nicotiana tabacum 'Xanthi') and lettuce (Lactuca sativa 'Crispa'), were evaluated by comparing various growth parameters between plants treated with the bacterium and those exposed to water or nutrient broth as control. In both tobacco and lettuce, fresh weight and length of shoots were increased upon exposure to Bacillus sp. JS. To explain the overall de novo expression of plant proteins by bacterial volatiles, two-dimensional gel electrophoresis was performed on samples from PGPR-treated tobacco plants. Our results showed that chlorophyll a/b binding proteins were significantly up-regulated, and total chlorophyll content was also increased. Our findings indicate the potential benefits of using Bacillus sp. JS as a growth-promoting factor in agricultural practice, and highlight the need for further research to explore these benefits.

Effect of Silicon on Growth, Physiology, and Cadmium Translocation of Tobacco (Nicotiana tabacum L.) in Cadmium-Contaminated Soil

Silicon (Si) offers beneficial effect on plants under cadmium (Cd) stress such as promoting plant growth and increasing resistance to heavy metal toxicity. In this study, a pot experiment was performed to study the role of Si in alleviating Cd toxicity in tobacco (Nicotiana tabacum L.) plants on a yellow soil taken from Guiyang, China. Nine treatments consisting of three concentrations of Cd (0, 1, and 5 mg kg−1) together with three Si levels (0, 1, and 4 g kg−1) were established. Plant growth parameters, Cd concentration, and the malondialdehyde (MDA), chlorophyll, and carotenoid contents were determined 100 d after transplanting of tobacco seedlings. Application of exogenous Si enhanced the growth of tobacco plants under Cd stress. When 5 mg kg−1 Cd was added, Si addition at 1 and 4 g kg−1 increased root, stem, and leaf biomass by 26.1%–43.3%, 33.7%–43.8%, and 50.8%–69.9%, respectively, compared to Si addition at 0 g kg−1. With Si application, the transfer factor of Cd in tobacco from root to shoot under both 1 and 5 mg kg−1 Cd treatments decreased by 21%. The MDA contents in the Si-treated tobacco plants declined by 5.5%–17.1% compared to those in the non-Si-treated plants, indicating a higher Cd tolerance. Silicon application also increased the chlorophyll and carotenoid contents by 33.9%–41% and 25.8%–47.3% compared to the Cd only treatments. Therefore, it could be concluded that Si application can alleviate Cd toxicity to tobacco by decreasing Cd partitioning in the shoots and MDA levels and by increasing chlorophyll and carotenoid contents, thereby contributing to lowering the potential health risks of Cd contamination.

English

Predatory arthropods, especially spiders, play a vital role in the control of insect pests in agro-ecosystems. Accordingly, two year field study was conducted at the Longyan Substation of Fujian Institute of Tobacco Agricultural Sciences in China to determine the effects of garlic and tobacco intercropping system on spiders and predatory arthropods. A total of 545 and 860 (in 2011 and 2012, respectively) individuals of predatory arthropods representing 14 families and 16 species were collected in the fields. The diversity indices of the predatory arthropod communities were obviously higher in tobacco-garlic intercropping system than in tobacco fields. The species richness and species abundance of the predatory arthropods collected in tobacco-garlic fields were significantly higher than that of the predatory arthropods collected in tobacco fields in both study years. Moreover, the values of these indices were obviously higher for spider abundance in tobacco-garlic fields than in tobacco fields during the middle stages of tobacco growth. Intercropping garlic in tobacco fields can increase the abundance of spiders and predatory arthropods, and this approach may be useful to control pests in tobacco fields. Key words: Tobacco-garlic, intercropping system, spider, predator arthropod, diversity.

Exogenous Glutathione Enhances Mercury Tolerance by Inhibiting Mercury Entry into Plant Cells.

Despite the increasing understanding of the crucial roles of glutathione (GSH) in cellular defense against heavy metal stress as well as oxidative stress, little is known about the functional role of exogenous GSH in mercury (Hg) tolerance in plants. Here, we provide compelling evidence that GSH contributes to Hg tolerance in diverse plants. Exogenous GSH did not mitigate the toxicity of cadmium (Cd), copper (Cu), or zinc (Zn), whereas application of exogenous GSH significantly promoted Hg tolerance during seed germination and seedling growth of Arabidopsis thaliana, tobacco, and pepper. By contrast, addition of buthionine sulfoximine, an inhibitor of GSH biosynthesis, severely retarded seed germination and seedling growth of the plants in the presence of Hg. The effect of exogenous GSH on Hg specific tolerance was also evident in the presence of other heavy metals, such as Cd, Cu, and Zn, together with Hg. GSH treatment significantly decreased H2O2 and O2- levels and lipid peroxidation, but increased chlorophyll content in the presence of Hg. Importantly, GSH treatment resulted in significantly less accumulation of Hg in Arabidopsis plants, and thin layer chromatography and nuclear magnetic resonance analysis revealed that GSH had much stronger binding affinity to Hg than to Cd, Cu, or Zn, suggesting that tight binding of GSH to Hg impedes Hg uptake, leading to low Hg accumulation in plant cells. Collectively, the present findings reveal that GSH is a potent molecule capable of conferring Hg tolerance by inhibiting Hg accumulation in plants.

Short Exogenous Peptides Regulate Expression of CLE, KNOX1, and GRF Family Genes in Nicotiana tabacum.

Exogenous short biologically active peptides epitalon (Ala-Glu-Asp-Gly), bronchogen (Ala-Glu-Asp-Leu), and vilon (Lys-Glu) at concentrations 10-7-10-9M significantly influence growth, development, and differentiation of tobacco (Nicotiana tabacum) callus cultures. Epitalon and bronchogen, in particular, both increase growth of calluses and stimulate formation and growth of leaves in plant regenerants. Because the regulatory activity of the short peptides appears at low peptide concentrations, their action to some extent is like that of the activity of phytohormones, and it seems to have signaling character and epigenetic nature. The investigated peptides modulate in tobacco cells the expression of genes including genes responsible for tissue formation and cell differentiation. These peptides differently modulate expression of CLE family genes coding for known endogenous regulatory peptides, the KNOX1 genes (transcription factor genes) and GRF (growth regulatory factor) genes coding for respective DNA-binding proteins such as topoisomerases, nucleases, and others. Thus, at the level of transcription, plants have a system of short peptide regulation of formation of long-known peptide regulators of growth and development. The peptides studied here may be related to a new generation of plant growth regulators. They can be used in the experimental botany, plant molecular biology, biotechnology, and practical agronomy.

Tobacco Growth Responses and Soil Properties to Rice-straw Biochar Applied on Yellow-brown Soil in Central China

Pot experiments were conducted to study the effect of straw biochar application on tobacco growth and soil fertility. The growth of ground parts of tobacco was promoted by biochar application at appropriate levels (0.2-1.0%), while it was inhibited by high-level (5%) biochar application. The growth of root system was promoted more extensively by biochar application at all levels tested than was the growth of the aboveground organs, with 5% biochar addition resulting in the highest root-shoot ratio, which also delayed the senility of the root system, including of lateral roots. The taproot length, the first- and second-order lateral roots and the root-shoot ratio of tobacco increased during the early growth stage but decreased at latter growth stage in all treatments. Moreover, with the increasing amount of biochar applied, soil pH and soil nutritional indicators including organic carbon, alkali-hydrolysable N, available P and available K increased with the highest value was observed in the 5% biochar treatment. Our results suggested that straw biochar application at appropriate levels (0.2-1.0%) would lead to an increase in soil fertility and promote tobacco growth. The field experiments are required to test the effect of biochar application on tobacco growth and soil environment with different soil types in tobacco planting area in China.