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 chara...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.展开更多
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 chara...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.展开更多
Drought has severely affected the yield and quality of commercial crops.The BRI1 family plays an important role in plant response to drought stress,and BRL3 gene plays an important role in the study of drought in Arab...Drought has severely affected the yield and quality of commercial crops.The BRI1 family plays an important role in plant response to drought stress,and BRL3 gene plays an important role in the study of drought in Arabidopsis thaliana.In this study,NtBRL3 was constructed as a vector and genetically transformed to obtain‘N.Tobacco K326’overexpression of NtBRL3.The enzyme activities of transgenic tobacco and wild-type tobacco were measured and transcriptome and metabolome analyses were performed.The results showed that the antioxidant enzymes of transgenic tobacco were more active under drought conditions,and 85 significantly differentially metabolites and 106 significantly differentially expressed genes were identified in the metabolome and transcriptome analyses,respectively.Transgenic tobacco NtBRL3ox demonstrated an excessive accumulation of droughtrelated metabolites,sugars such as sucrose and maltotetraose,and amino acids such as proline,compared with WT.We discovered drought-related differential genes in the root transcriptome,among which LOX6,RD22,WSD1,CCD8,and UGT were key genes which play an important role in plant response to drought stress.Our results demonstrate that NtBRL3 overexpression in K326 enhances drought resistance in transgenic tobacco.展开更多
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 in...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.展开更多
Monosomic lines of Nicotiana tabacum are helpful to confirm the location of genes on specific chromosomes. In the cross N. nudicaulis and N. tabacum, hybrid seedlings express lethal symptoms, which are controlled by t...Monosomic lines of Nicotiana tabacum are helpful to confirm the location of genes on specific chromosomes. In the cross N. nudicaulis and N. tabacum, hybrid seedlings express lethal symptoms, which are controlled by the S subgenome of N. tabacum. To identify the responsible chromosome, we needed to produce chromosome lacking lines (CLLs) of N. tabacum L. “Red Russian” and use them to cross with N. nudicaulis. From a cross of (N. tabacum × N. tomentosiformis) × N. tabacum, 380 BC1 individuals were obtained. Using a Haplo-Q line (a monosomic line lacking the single linkage group 11) and N. tabacum, we found that qPCR is a simple and reliable screening method for CLLs of N. tabacum. The marker PT30342 is located on linkage group 11, and the -Ct value (Ct Actin - Ct PT30342) was 2.0 for a disomic line and was 1.097 for a Haplo-Q line. By the use of flow cytometry, qPCR and chromosome counting together as a screening method, we identified 6 CLLs lacking 2 to 6 chromosomes. Compared with conventional methods, our method is a rapid technique for making and screening CLLs ofthe S or S/T subgenome of N. tabacum. Further, these CLLs will be useful to identify the location of two or more factors on chromosomes controlling a variety of genetic problems affecting breeding. Here, we only made CLLs of the S or S/T subgenome of N. tabacum. We will use the method established in this study to produce CLLs of the T subgenome of N. tabacum, and gather a full set of CLLs of N. tabacum. qPCR could also be applied to the identification of chromosome aberrations in other plants.展开更多
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 a...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.展开更多
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 ...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.展开更多
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 ...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.展开更多
Vacuolar ATPase is the key enzyme in the aspect of plant stress, which contains 13 subunits. In this study, VHA-c which was cloned from the salt-tolerant plants Iris lacteal was transformed into tobacco, and then trea...Vacuolar ATPase is the key enzyme in the aspect of plant stress, which contains 13 subunits. In this study, VHA-c which was cloned from the salt-tolerant plants Iris lacteal was transformed into tobacco, and then treated the transgenic tobacco with 0.7% NaC1 for 7 days. Detected the MDA content, the SOD activity and the POD activity. Moreover, the transgenic plants displayed obviously better growth than the normal plants under salt stress. These results suggested that VHA-c could confer the stress tolerance through enhancing the POD and the SOD activities, and by protecting membranes from damage by decreasing lipid peroxidation under salt stress.展开更多
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 fee...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.展开更多
The constitutive promoter of cauliflower mosaic virus 35S （CaMV 35S） is a polar unidirectional promoter and is widely used in plant genetic engineering. In the present study, the unidirectional CaMV 35S promoter has...The constitutive promoter of cauliflower mosaic virus 35S （CaMV 35S） is a polar unidirectional promoter and is widely used in plant genetic engineering. In the present study, the unidirectional CaMV 35S promoter has been modified to a bi-directional promoter by fusing its minimal promoter element to the 5＇ end of CaMV 35S promoter in the opposite orientation. To qualitatively and quantitatively estimate its bi-directional transcriptional function and activity, two visible reporter genes, gusA （13-glucuronidase, GUS） and gfp （green fluorescent protein, GFP）, were fused to the two ends of the promoter in bi-orientations ending with NOS terminator sequences, respectively. Stable expression of gusA and gfp genes in transgenic tobacco （Nicotiana tabacum L.） was visulized by histochemically staining for GUS and fluorescence microscopic observation under UV for GFP in transgenic plants. The expression of two reporter genes showed that the constructed bi-directional promoter did have the bi-directional transcriptional function in both expected orientations. The quantitative estimation of GUS and GFP were determined on a HITACHI F1000 Fluorescence Spectrophotometer with various wavelengths of excitation and emission. The GUS activity varied from g to 250 pmol 4-MU/min/mg protein and the GFP content varied from 0.9 to 1.8 μg/ mg protein in various lines of transgenic tobacco plants. Higher GUS activity generally coupled with lower GFP content, and vice versa.展开更多
We compared the expression patterns of three representative genes in undamaged tomato and tobacco plants in response to exposure to either tomato or tobacco fed on by Helicoverpa armigera (cotton bollworm). When tomat...We compared the expression patterns of three representative genes in undamaged tomato and tobacco plants in response to exposure to either tomato or tobacco fed on by Helicoverpa armigera (cotton bollworm). When tomato and tobacco, two species of one family, were incubated in the chambers with the tomato plants damaged by the cotton bollworm, the expression of the PR1, BGL2, and PAL genes was up-regulated in leaves of both plants. However, the levels of gene expression were significantly higher in the tomato than that in the tobacco. In addition, the activities of enzymes, peroxidase, polyphenol oxidase, and lipoxygenase were found to be higher in the tomato than those in the tobacco. Similar results were obtained when the damaged plants were replaced by the tobacco.展开更多
文摘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.
基金supported in part by the Key Scientific and Technological Development Project from State To-bacco Monopoly Bureau,China (110200701021,110200701022)the open subject from State Key Laboratory of Plant Physiology and Biochemistry,China(PPB08004)
文摘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.
基金supported by the Science and Technology Project of Guizhou Tobacco Company(2021XM04)the Creation of“Tobacco T-DNA Activation Insertion Mutant Library and Screening of Important Trait Mutants”Project of Guizhou University Talent Introduction(Guizhou University Hezi[2013]50).
文摘Drought has severely affected the yield and quality of commercial crops.The BRI1 family plays an important role in plant response to drought stress,and BRL3 gene plays an important role in the study of drought in Arabidopsis thaliana.In this study,NtBRL3 was constructed as a vector and genetically transformed to obtain‘N.Tobacco K326’overexpression of NtBRL3.The enzyme activities of transgenic tobacco and wild-type tobacco were measured and transcriptome and metabolome analyses were performed.The results showed that the antioxidant enzymes of transgenic tobacco were more active under drought conditions,and 85 significantly differentially metabolites and 106 significantly differentially expressed genes were identified in the metabolome and transcriptome analyses,respectively.Transgenic tobacco NtBRL3ox demonstrated an excessive accumulation of droughtrelated metabolites,sugars such as sucrose and maltotetraose,and amino acids such as proline,compared with WT.We discovered drought-related differential genes in the root transcriptome,among which LOX6,RD22,WSD1,CCD8,and UGT were key genes which play an important role in plant response to drought stress.Our results demonstrate that NtBRL3 overexpression in K326 enhances drought resistance in transgenic tobacco.
基金financial support by the National Natural Science Foundation of China(32001934)the Key Science and Technology Project of Sichuan Tobacco Company,China(SCYC202114)。
文摘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.
文摘Monosomic lines of Nicotiana tabacum are helpful to confirm the location of genes on specific chromosomes. In the cross N. nudicaulis and N. tabacum, hybrid seedlings express lethal symptoms, which are controlled by the S subgenome of N. tabacum. To identify the responsible chromosome, we needed to produce chromosome lacking lines (CLLs) of N. tabacum L. “Red Russian” and use them to cross with N. nudicaulis. From a cross of (N. tabacum × N. tomentosiformis) × N. tabacum, 380 BC1 individuals were obtained. Using a Haplo-Q line (a monosomic line lacking the single linkage group 11) and N. tabacum, we found that qPCR is a simple and reliable screening method for CLLs of N. tabacum. The marker PT30342 is located on linkage group 11, and the -Ct value (Ct Actin - Ct PT30342) was 2.0 for a disomic line and was 1.097 for a Haplo-Q line. By the use of flow cytometry, qPCR and chromosome counting together as a screening method, we identified 6 CLLs lacking 2 to 6 chromosomes. Compared with conventional methods, our method is a rapid technique for making and screening CLLs ofthe S or S/T subgenome of N. tabacum. Further, these CLLs will be useful to identify the location of two or more factors on chromosomes controlling a variety of genetic problems affecting breeding. Here, we only made CLLs of the S or S/T subgenome of N. tabacum. We will use the method established in this study to produce CLLs of the T subgenome of N. tabacum, and gather a full set of CLLs of N. tabacum. qPCR could also be applied to the identification of chromosome aberrations in other plants.
基金This study was supported by the Major Special Projects for the Cultivation of New National Genetically Modified Varieties(Contract No.2016ZX08010013-002)the Guizhou Science and Technology Plan Project(Contract No.[2016]7449)the Talent Training Program of Guizhou University(Contract No.[2018]5781).
文摘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.
文摘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.
文摘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.
基金Supported by the Post-doctoral Research Start-up Funding of Heilongjiang Province (LBH-210144)the Post-doctoral Funds Project of Heilongjiang Province (520-415037)
文摘Vacuolar ATPase is the key enzyme in the aspect of plant stress, which contains 13 subunits. In this study, VHA-c which was cloned from the salt-tolerant plants Iris lacteal was transformed into tobacco, and then treated the transgenic tobacco with 0.7% NaC1 for 7 days. Detected the MDA content, the SOD activity and the POD activity. Moreover, the transgenic plants displayed obviously better growth than the normal plants under salt stress. These results suggested that VHA-c could confer the stress tolerance through enhancing the POD and the SOD activities, and by protecting membranes from damage by decreasing lipid peroxidation under salt stress.
文摘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.
文摘The constitutive promoter of cauliflower mosaic virus 35S （CaMV 35S） is a polar unidirectional promoter and is widely used in plant genetic engineering. In the present study, the unidirectional CaMV 35S promoter has been modified to a bi-directional promoter by fusing its minimal promoter element to the 5＇ end of CaMV 35S promoter in the opposite orientation. To qualitatively and quantitatively estimate its bi-directional transcriptional function and activity, two visible reporter genes, gusA （13-glucuronidase, GUS） and gfp （green fluorescent protein, GFP）, were fused to the two ends of the promoter in bi-orientations ending with NOS terminator sequences, respectively. Stable expression of gusA and gfp genes in transgenic tobacco （Nicotiana tabacum L.） was visulized by histochemically staining for GUS and fluorescence microscopic observation under UV for GFP in transgenic plants. The expression of two reporter genes showed that the constructed bi-directional promoter did have the bi-directional transcriptional function in both expected orientations. The quantitative estimation of GUS and GFP were determined on a HITACHI F1000 Fluorescence Spectrophotometer with various wavelengths of excitation and emission. The GUS activity varied from g to 250 pmol 4-MU/min/mg protein and the GFP content varied from 0.9 to 1.8 μg/ mg protein in various lines of transgenic tobacco plants. Higher GUS activity generally coupled with lower GFP content, and vice versa.
文摘We compared the expression patterns of three representative genes in undamaged tomato and tobacco plants in response to exposure to either tomato or tobacco fed on by Helicoverpa armigera (cotton bollworm). When tomato and tobacco, two species of one family, were incubated in the chambers with the tomato plants damaged by the cotton bollworm, the expression of the PR1, BGL2, and PAL genes was up-regulated in leaves of both plants. However, the levels of gene expression were significantly higher in the tomato than that in the tobacco. In addition, the activities of enzymes, peroxidase, polyphenol oxidase, and lipoxygenase were found to be higher in the tomato than those in the tobacco. Similar results were obtained when the damaged plants were replaced by the tobacco.
