Tobacco Research Institute

chemicals delivered to users and the air pollution generated by the exhaled aerosol. -liquids are flavored, including tobacco, menthol, coffee, fruit, candy, and alcohol flavors, as well as unusual flavors such as cola and Belgian waffle. 3 Flavored (conventional) tobacco products are used disproportionately by youth and initiators

Modern sugarcanes are polyploid interspecific hybrids, combining high sugar content from Saccharum officinarum with hardiness, disease resistance and ratooning of Saccharum spontaneum. Sequencing of a haploid S. spontaneum, AP85-441, facilitated the assembly of 32 pseudo-chromosomes comprising 8 homologous groups of 4 members each, bearing 35,525 genes with alleles defined. The reduction of basic chromosome number from 10 to 8 in S. spontaneum was caused by fissions of 2 ancestral chromosomes followed by translocations to 4 chromosomes. Surprisingly, 80% of nucleotide binding site-encoding genes associated with disease resistance are located in 4 rearranged chromosomes and 51% of those in rearranged regions. Resequencing of 64 S. spontaneum genomes identified balancing selection in rearranged regions, maintaining their diversity. Introgressed S. spontaneum chromosomes in modern sugarcanes are randomly distributed in AP85-441 genome, indicating random recombination among homologs in different S. spontaneum accessions. The allele-defined Saccharum genome offers new knowledge and resources to accelerate sugarcane improvement.

KEY MESSAGE: Results from various expansin related studies have demonstrated that expansins present an opportunity to improve various crops in many different aspects ranging from yield and fruit ripening to improved stress tolerance. The recent advances in expansin studies were reviewed. Besides producing the strength that is needed by the plants, cell walls define cell shape, cell size and cell function. Expansins are cell wall proteins which consist of four sub families; α-expansin, β-expansin, expansin-like A and expansin-like B. These proteins mediate cell wall loosening and they are present in all plants and in some microbial organisms and other organisms like snails. Decades after their initial discovery in cucumber, it is now clear that these small proteins have diverse biological roles in plants. Through their ability to enable the local sliding of wall polymers by reducing adhesion between adjacent wall polysaccharides and the part they play in cell wall remodeling after cytokinesis, it is now clear that expansins are required in almost all plant physiological development aspects from germination to fruiting. This is shown by the various reports from different studies using various molecular biology approaches such as gene achieve these many roles through their non-enzymatic wall loosening ability. This paper reviews and summarizes some of the reported functions of expansins and outlines the potential uses of expansins in crop improvement programs.

Leaf senescence, the last stage of leaf development, is a type of postmitotic senescence and is characterized by the functional transition from nutrient assimilation to nutrient remobilization which is essential for plants' fitness. The initiation and progression of leaf senescence are regulated by a variety of internal and external factors such as age, phytohormones, and environmental stresses. Significant breakthroughs in dissecting the molecular mechanisms underpinning leaf senescence have benefited from the identification of senescence-altered mutants through forward genetic screening and functional assessment of hundreds of senescence-associated genes (SAGs) via reverse genetic research in model plant Arabidopsis thaliana as well as in crop plants. Leaf senescence involves highly complex genetic programs that are tightly tuned by multiple layers of regulation, including chromatin and transcription regulation, post-transcriptional, translational and post-translational regulation. Due to the significant impact of leaf senescence on photosynthesis, nutrient remobilization, stress responses, and productivity, much effort has been made in devising strategies based on known senescence regulatory mechanisms to manipulate the initiation and progression of leaf senescence, aiming for higher yield, better quality, or improved horticultural performance in crop plants. This review aims to provide an overview of leaf senescence and discuss recent advances in multi-dimensional regulation of leaf senescence from genetic and molecular network perspectives. We also put forward the key issues that need to be addressed, including the nature of leaf age, functional stay-green trait, coordination between different regulatory pathways, source-sink relationship and nutrient remobilization, as well as translational researches on leaf senescence.

A crude gum, a fixed oil and two purified components of Nigella sativa seed, thymoquinone (TQ) and dithymoquinone (DIM), were assayed in vitro for their cytotoxicity for several parental and multi-drug resistant (MDR) human tumor cell lines. Although as much as 1% w/v of the gum or oil was devoid of cytotoxicity, both TQ and DIM were cytotoxic for all of the tested cell lines (IC50's 78 to 393 microM). Both the parental cell lines and their corresponding MDR variants, over 10-fold more resistant to the standard antineoplastic agents doxorubicin (DOX) and etoposide (ETP), as compared to their respective parental controls, were equally sensitive to TQ and DIM. The inclusion of the competitive MDR modulator quinine in the assay reversed MDR Dx-5 cell resistance to DOX and ETP by 6- to 16-fold, but had no effect on the cytotoxicity of TQ or DIM. Quinine also increased MDR Dx-5 cell accumulation of the P-glycoprotein substrate 3H-taxol in a dose-dependent manner. However, neither TQ nor DIM significantly altered cellular accumulation of 3H-taxol. The inclusion of 0.5% v/v of the radical scavenger DMSO in the assay reduced the cytotoxicity of DOX by as much as 39%, but did not affect that of TQ or DIM. These studies suggest that TQ and DIM, which are cytotoxic for several types of human tumor cells, may not be MDR substrates, and that radical generation may not be critical to their cytotoxic activity.

Tea is an important global beverage crop and is largely clonally propagated. Despite previous studies on the species, its genetic and evolutionary history deserves further research. Here, we present a haplotype-resolved assembly of an Oolong tea cultivar, Tieguanyin. Analysis of allele-specific expression suggests a potential mechanism in response to mutation load during long-term clonal propagation. Population genomic analysis using 190 Camellia accessions uncovered independent evolutionary histories and parallel domestication in two widely cultivated varieties, var. sinensis and var. assamica. It also revealed extensive intra- and interspecific introgressions contributing to genetic diversity in modern cultivars. Strong signatures of selection were associated with biosynthetic and metabolic pathways that contribute to flavor characteristics as well as genes likely involved in the Green Revolution in the tea industry. Our results offer genetic and molecular insights into the evolutionary history of Camellia sinensis and provide genomic resources to further facilitate gene editing to enhance desirable traits in tea crops.

Abstract The mechanism of selenium-mediated salt tolerance has not been fully clarified. This study investigated the possible role of selenium (Se) in regulating maize salt tolerance. A pot experiment was conducted to investigate the role of Se (0, 1, 5 and 25 μM Na 2 SeO 3 ) in photosynthesis, antioxidative capacity and ion homeostasis in maize under salinity. The results showed that Se (1 μM) relieved the salt-induced inhibitory effects on the plant growth and development of 15-day-old maize plants. Se application (1 μM) also increased the net photosynthetic rate and alleviated the damage to chloroplast ultrastructure induced by NaCl. The superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities were increased, and ZmMPK5, ZmMPK7 and ZmCPK11 were markedly up-regulated in the roots of Se-treated plants, likely contributing to the improvement of antioxidant defence systems under salinity. Moreover, 1 μM Se increased K + in the shoots while decreasing Na + in the roots, indicating that Se up-regulates ZmNHX1 in the roots, which may be involved in Na + compartmentalisation under salinity. The findings from this single experiment require repetition together with measurement of reactive oxygen species (ROS), but nevertheless suggest that exogenous Se alleviates salt stress in maize via the improvement of photosynthetic capacity, the activities of antioxidant enzymes and the regulation of Na + homeostasis.

Fusarium graminearum is an important plant pathogen that causes head blight of major cereal crops. The fungus produces mycotoxins that are harmful to animal and human. In this study, a systematic analysis of 17 phenotypes of the mutants in 657 Fusarium graminearum genes encoding putative transcription factors (TFs) resulted in a database of over 11,000 phenotypes (phenome). This database provides comprehensive insights into how this cereal pathogen of global significance regulates traits important for growth, development, stress response, pathogenesis, and toxin production and how transcriptional regulations of these traits are interconnected. In-depth analysis of TFs involved in sexual development revealed that mutations causing defects in perithecia development frequently affect multiple other phenotypes, and the TFs associated with sexual development tend to be highly conserved in the fungal kingdom. Besides providing many new insights into understanding the function of F. graminearum TFs, this mutant library and phenome will be a valuable resource for characterizing the gene expression network in this fungus and serve as a reference for studying how different fungi have evolved to control various cellular processes at the transcriptional level.

Genetic map is a linear arrangement of the relative positions of sites in the chromosome or genome based on the recombination frequency between genetic markers. It is the important basis for genetic analysis. Several kinds of software have been designed for genetic mapping, but all these tools require users to write or edit code, making it time-costing and difficult for researchers without programming skills to handle with. Here, MG2C, a new online tool was designed, based on PERL and SVG languages.Users can get a standard genetic map, only by providing the location of genes (or quantitative trait loci) and the length of the chromosome, without writing additional code. The operation interface of MG2C contains three sections: data input, data output and parameters. There are 33 attribute parameters in MG2C, which are further divided into 8 modules. Values of the parameters can be changed according to the users' requirements. The information submitted by users will be transformed into the genetic map in SVG file, which can be further modified by other image processing tools.MG2C is a user-friendly and time-saving online tool for drawing genetic maps, especially for those without programming skills. The tool has been running smoothly since 2015, and updated to version 2.1. It significantly lowers the technical barriers for the users, and provides great convenience for the researchers.

OBJECTIVES: To collect available international data on nicotine dependence as defined by the Fagerström Test of Nicotine Dependence, and to compare levels of dependence among countries and categories of smokers. DATA SOURCES: Published and unpublished studies known to the authors and a search of EMBASE from 1985-1995. STUDY SELECTION: Studies included were those based on a nationally representative sample of a country's population, or a sample of smokers seeking cessation assistance. DATA SYNTHESIS: Smokers who seek help in stopping smoking are much more dependent than the average smoker. Men consistently score higher on dependence than women. Ex-smokers appear to have lower dependence than current smokers. A country with low smoking prevalence, the United States, seems to have smokers with higher dependence scores than countries where smoking is more prevalent (such as Austria and Poland). CONCLUSIONS: Successful tobacco control may result in a higher dependence among the remaining smokers (due to selective quitting by low-dependent smokers). The remaining highly dependent smokers may need more intensive treatment.

Among abiotic stressors, drought and salinity seriously affect crop growth worldwide. In plants, research has aimed to increase stress-responsive protein synthesis upstream or downstream of the various transcription factors (TFs) that alleviate drought and salinity stress. TFs play diverse roles in controlling gene expression in plants, which is necessary to regulate biological processes, such as development and environmental stress responses. In general, plant responses to different stress conditions may be either abscisic acid (ABA)-dependent or ABA-independent. A detailed understanding of how TF pathways and ABA interact to cause stress responses is essential to improve tolerance to drought and salinity stress. Despite previous progress, more active approaches based on TFs are the current focus. Therefore, the present review emphasizes the recent advancements in complex cascades of gene expression during drought and salinity responses, especially identifying the specificity and crosstalk in ABA-dependent and -independent signaling pathways. This review also highlights the transcriptional regulation of gene expression governed by various key TF pathways, including AP2/ERF, bHLH, bZIP, DREB, GATA, HD-Zip, Homeo-box, MADS-box, MYB, NAC, Tri-helix, WHIRLY, WOX, WRKY, YABBY, and zinc finger, operating in ABA-dependent and -independent signaling pathways.

Anthocyanins and proanthocyanidins are widespread in the plant kingdom and are involved in important bioactivities, such as antioxidation. These flavonoids can reduce the risk of cardiovascular diseases, cancer, high blood pressure, hyperlipidemia, and diabetes; consequently, they are widely studied for disease prevention and treatment. In this review, we summarize recent advances in our understanding of the chemical structures, food sources, and bioactivities of these compounds. We also discuss recent developments and trends related to anthocyanin- and proanthocyanidin-derived products. This review provides insights to inform related research and inspire future studies to help realize the potential of these plant pigments.

The rapid wide-scale spread of fall armyworm (Spodoptera frugiperda) has caused serious crop losses globally. However, differences in the genetic background of subpopulations and the mechanisms of rapid adaptation behind the invasion are still not well understood. Here we report the assembly of a 390.38-Mb chromosome-level genome of fall armyworm derived from south-central Africa using Pacific Bioscience (PacBio) and Hi-C sequencing technologies, with scaffold N50 of 12.9 Mb and containing 22,260 annotated protein-coding genes. Genome-wide resequencing of 103 samples and strain identification were conducted to reveal the genetic background of fall armyworm populations in China. Analysis of genes related to pesticide- and Bacillus thuringiensis (Bt) resistance showed that the risk of fall armyworm developing resistance to conventional pesticides is very high. Laboratory bioassay results showed that insects invading China carry resistance to organophosphate and pyrethroid pesticides, but are sensitive to genetically modified maize expressing the Bt toxin Cry1Ab in field experiments. Additionally, two mitochondrial fragments were found to be inserted into the nuclear genome, with the insertion event occurring after the differentiation of the two strains. This study represents a valuable advance toward improving management strategies for fall armyworm.

Tobacco stalks are an abundant biomass resource which are otherwise treated as waste. In this work, the effect of hydrothermal carbonization temperature and time on the structures, chemical compositions and combustion characteristics of hydrochars obtained from tobacco stalks were evaluated. The carbon content, higher heating value, and energy yield increased with accompanying decrease in hydrogen and oxygen contents with the increase of treatment temperature and time. The evolution of the H/C and O/C atomic ratios indicated dehydration and devolatilization processes occurred during hydrothermal carbonization. The weight loss, combustion range and characteristic temperatures of tobacco stalks were significantly modified after hydrothermal carbonization, resulting in higher ignition temperatures and higher energy density. The kinetics model, Coats-Redfern method revealed the activation energy of hydrochars in zone 2 and 3 were among 43.7-74.8kJ/mol and 46.7-85.8kJ/mol, respectively. Our results show that hydrothermal carbonization reaction can facilitate transforming tobacco stalks into energy-rich solid fuel.

OBJECTIVE: To compare the efficacy and safety of 22-mg and 44-mg doses of transdermal nicotine therapy when it is paired with minimal, individual, or group counseling to improve smoking cessation rates. DESIGN: An 8-week clinical trial (4 weeks double-blind followed by 4 weeks open label) using random assignment of participants to both dose (22 or 44 mg) and counseling (minimal, individual, or group) conditions. PARTICIPANTS: Daily cigarette smokers (> or = 15 cigarettes per day for at least 1 year) who volunteered to participate in a study of smoking cessation treatment. A total of 504 participants were enrolled at two sites. INTERVENTION: Four weeks of 22- or 44-mg transdermal nicotine therapy followed by 4 weeks of dosage reduction (2 weeks of 22 mg followed by 2 weeks of 11 mg). Counseling consisted of a self-help pamphlet (minimal); a self-help pamphlet, a brief physician motivational message, and three brief (< 15 minutes) follow-up visits with a nurse (individual); or the pamphlet, the motivational message, and eight weekly 1-hour group smoking cessation counseling visits (group). All participants returned weekly to turn in questionnaires and for assessment of their smoking status. MAIN OUTCOME MEASURES: Abstinence from smoking was based on self-report, confirmed by an expired carbon monoxide concentration lower than 10 ppm. Withdrawal severity was assessed by means of an eight-item self-report questionnaire completed daily. RESULTS: Smoking cessation rates for the two nicotine patch doses and three levels of counseling did not differ significantly at either 8 weeks or 26 weeks following the quit date. Among those receiving minimal contact, the 44-mg dose produced greater abstinence at 4 weeks than did the 22-mg dose (68% vs 45%; P < .01). Participants receiving minimal-contact adjuvant treatment were less likely to be abstinent at the end of 4 weeks than those receiving individual or group counseling (56% vs 67%; P < .05). The 44-mg dose decreased desire to smoke more than the 22-mg dose, but this effect was not related to success in quitting smoking. Transdermal nicotine therapy at doses of 44 mg produced a significantly greater frequency of nausea (28%), vomiting (10%), and erythema with edema at the patch site (30%) than did a 22-mg dose (10%, 2%, and 13%, respectively; P < .01 for each adverse effect). Three serious adverse events occurred during use of the 44-mg patch dose. CONCLUSIONS: There does not appear to be any general, sustained benefit of initiating transdermal nicotine therapy with a 44-mg patch dose or of providing intense adjuvant smoking cessation treatment. The two doses and all adjuvant treatments produced equivalent effects at the 26-week follow-up, and the higher patch dose produced more adverse effects. Higher-dose (44-mg) nicotine replacement does not appear to be indicated for general clinical populations, although it may provide short-term benefit to some smokers attempting to quit with minimal adjuvant treatment.

Abstract Monoculture and improper management may reduce soil fertility and deteriorate soil structure in Black soils (Mollisols) of Northeast China. The experiment was carried out from 2015 to 2016 in Black Soils comprising five cropping systems: continuous corn (CC), soybean-corn rotation (SC), corn-soybean rotation (CS), fallow-corn (FC), and fallow-soybean (FS). Our results showed that CS and FS treatments significantly increased mean weight diameter (MWD) and fractal dimension (D) in mechanical stability aggregates (MSAs), and increased MWD and geometric mean diameter (GMD) in water-stable aggregates (WSAs) compared with CC treatment. These two treatments were also significantly increased water-stable aggregates stability rate (WSAR), but decreased percentage of aggregates destruction (PAD) than CC treatment. Meanwhile, CS and FS treatments exhibited a higher carbon accumulation than CC treatment in bulk soils. Soil organic carbon (SOC) concentration in WSA 0.106-0.25 ,WSA 2-5 mm and WSA 0.5-1 mm had a dominant effect on aggregate stability. Simutaneously, SOC in WSA &gt;5 mm affected SOC concentration in bulk soils. As a whole, the CS and FS treatments can increase the percentage of macro-aggregates, enhance aggregate stability, as well as increase SOC concentration in bulk soils and all soil aggregate sizes.

As a ubiquitous secondary messenger in plant signaling systems, calcium ions (Ca2+) play essential roles in plant growth and development. Within the cellular signaling network, the accurate decoding of diverse Ca2+ signal is a fundamental molecular event. Calcium-dependent protein kinases (CDPKs), identified commonly in plants, are a kind of vital regulatory protein deciphering calcium signals triggered by various developmental and environmental stimuli. This review chiefly introduces Ca2+ distribution in plant cells, the classification of Arabidopsis thaliana CDPKs (AtCDPKs), the identification of the Ca2+-AtCDPK signal transduction mechanism and AtCDPKs’ functions involved in plant growth regulation and abiotic stress responses. The review presents a comprehensive overview of AtCDPKs and may contribute to the research of CDPKs in other plants.

Real-time quantitative polymerase chain reaction (qPCR) is one of the most important methods for analyzing the expression patterns of target genes. However, successful qPCR experiments rely heavily on the use of high-quality primers. Various qPCR primer databases have been developed to address this issue, but these databases target only a few important organisms. Here, we developed the qPrimerDB database, founded on an automatic gene-specific qPCR primer design and thermodynamics-based validation workflow. The qPrimerDB database is the most comprehensive qPCR primer database available to date, with a web front-end providing gene-specific and pre-computed primer pairs across 147 important organisms, including human, mouse, zebrafish, yeast, thale cress, rice and maize. In this database, we provide 3331426 of the best primer pairs for each gene, based on primer pair coverage, as well as 47760359 alternative gene-specific primer pairs, which can be conveniently batch downloaded. The specificity and efficiency was validated for qPCR primer pairs for 66 randomly selected genes, in six different organisms, through qPCR assays and gel electrophoresis. The qPrimerDB database represents a valuable, timesaving resource for gene expression analysis. This resource, which will be routinely updated, is publically accessible at http://biodb.swu.edu.cn/qprimerdb.

Because of great challenges and workload in deleting genes on a large scale, the functions of most genes in pathogenic fungi are still unclear. In this study, we developed a high-throughput gene knockout system using a novel yeast-Escherichia-Agrobacterium shuttle vector, pKO1B, in the rice blast fungus Magnaporthe oryzae. Using this method, we deleted 104 fungal-specific Zn(2)Cys(6) transcription factor (TF) genes in M. oryzae. We then analyzed the phenotypes of these mutants with regard to growth, asexual and infection-related development, pathogenesis, and 9 abiotic stresses. The resulting data provide new insights into how this rice pathogen of global significance regulates important traits in the infection cycle through Zn(2)Cys(6)TF genes. A large variation in biological functions of Zn(2)Cys(6)TF genes was observed under the conditions tested. Sixty-one of 104 Zn(2)Cys(6) TF genes were found to be required for fungal development. In-depth analysis of TF genes revealed that TF genes involved in pathogenicity frequently tend to function in multiple development stages, and disclosed many highly conserved but unidentified functional TF genes of importance in the fungal kingdom. We further found that the virulence-required TF genes GPF1 and CNF2 have similar regulation mechanisms in the gene expression involved in pathogenicity. These experimental validations clearly demonstrated the value of a high-throughput gene knockout system in understanding the biological functions of genes on a genome scale in fungi, and provided a solid foundation for elucidating the gene expression network that regulates the development and pathogenicity of M. oryzae.

BRI1-EMS suppressor (BES)/brassinazole-resistant (BZR) family transcription factors are involved in a variety of physiological processes, but the biological functions of some BES/BZR transcription factors remain unknown; moreover, it is not clear if any of these proteins function in the regulation of plant stress responses. Here, wheat (Triticum aestivum) brassinazole-resistant 2 (TaBZR2)-overexpressing plants exhibited drought tolerant phenotypes, whereas downregulation of TaBZR2 in wheat by RNA interference resulted in elevated drought sensitivity. electrophoretic mobility shift assay and luciferase reporter analysis illustrate that TaBZR2 directly interacts with the gene promoter to activate the expression of T. aestivum glutathione s-transferase-1 (TaGST1), which functions positively in scavenging drought-induced superoxide anions (O2 −). Moreover, TaBZR2 acts as a positive regulator in brassinosteroid (BR) signaling. Exogenous BR treatment enhanced TaBZR2-mediated O2 − scavenging and antioxidant enzyme gene expression. Taken together, we demonstrate that a BES/BZR family transcription factor, TaBZR2, functions positively in drought responses by activating TaGST1 and mediates the crosstalk between BR and drought signaling pathways. Our results thus provide new insights into the mechanisms underlying how BES/BZR family transcription factors contribute to drought tolerance in wheat.