The modeling ability of a stand-alone version of the Simple Biosphere Model 2(SiB2) was tested mainly through diagnosing the simulated latent heat(LE),sensible heat(H),CO2 flux,and air temperature at the Tongyu ...The modeling ability of a stand-alone version of the Simple Biosphere Model 2(SiB2) was tested mainly through diagnosing the simulated latent heat(LE),sensible heat(H),CO2 flux,and air temperature at the Tongyu field observation station(44°25'N,122°52'E,184 m elevation) of Coordinated Enhanced Observing Period(CEOP),where the land cover is cropland and grassland.In the whole year of 2003,the canopy height and the leaf area index was variable.During non-growth period,the surface would become bare,while during the growth period,the canopy height could reach 2.0 m high over cropland and 0.8 m high over grassland,respectively,and max leaf area index could reach 4.2 and 2.4,respectively.The model was initialized with measurement and driven by half-hourly atmospheric observations.The simulation values for 2003 were compared against measurements.Results show that the model is of a good ability of simulating the hourly latent heat(LE),sensible heat(H),CO2 flux and temperature during the growth period.Moreover,the daily LE,H and CO2 flux simulated by SiB2 could reflect their yearly change reasonably.However,the model may overestimate the H generally.展开更多
Sex expression in Sagittaria guyanensis H.B.K. subsp. lappula (D. Don) Bojin is typically andromonoecious while the other species in the same genus are basically monoecious. The evolutionary advantages of male...Sex expression in Sagittaria guyanensis H.B.K. subsp. lappula (D. Don) Bojin is typically andromonoecious while the other species in the same genus are basically monoecious. The evolutionary advantages of male flowers and hermaphrodite flowers in S. guyanensis subsp. lappula were assessed by measuring sex allocation and pollen movements in two wild populations of the species. Two cultivated populations served as controls. The percentage of male flowers was very low in the two wild populations in Dongxiang, Jiangxi Province and Wuyishan, Fujian Province, viz., 2.48% and 0.96% respectively. In the two cultivated populations, male flower percentage significantly increased when the soil was of higher nutrient content. This indicates that the allocation to male versus female reproduction might change in response to environmental factors. Pollen production per male flower was 4.1 times higher than that of a hermaphrodite flower. The floral shape and size of male and hermaphrodite flowers were similar. No difference was observed between these dimorphological flowers in pollen germination rate in vitro and in the speed of pollen tube growth in vivo . Anthesis was only 4-5 h. Male flowers usually opened 0.5 h earlier than hermaphrodite flowers. An unexpected finding was that no pollen from the male flowers was found on the stigmas of the hermaphrodite flowers, in spite of the occasional visits by insects to both types of flowers in both wild and control populations. A consistent pattern of fruit development was found to exist in open pollinated flowers as well as in flowers that had been bagged. The sex ratios did not have significant influence on fruit set. Approximately 25% of the pistils in a gynoecium failed to develop into fruits because no pollen was deposited on them, indicating that the fruit set of this andromonoecious plant is mainly affected by pollen limitation rather than resource limitation. Reproduction in S. guyanensis subsp. lappula in the habitats was dependent on self_pollination in hermaphrodite flowers. The male flowers in this species might be a potential source of additional pollination and may facilitate cross_pollination. The fact that the flowers of monoecious species in Sagittaria pollinated by a wide diversity of insect visitors may contribute enormously to the diversification of sex expression in this genus.展开更多
[Objective] This paper aimed at revealing the rules of phenotypic variation of Leymus chinensis in Zhalong wetlands and providing the scientific and theoretical bases for devising protection strategies of Leymus chine...[Objective] This paper aimed at revealing the rules of phenotypic variation of Leymus chinensis in Zhalong wetlands and providing the scientific and theoretical bases for devising protection strategies of Leymus chinensis populations in Zhalong National Nature Reserve.[Method] Four phenotypic traits of five Leymus chinensis populations in Zhalong Wetlands were comparison and analysis using principal component analysis method and UPGMA cluster analysis method.[Result] There were significant differences among the four phenotypic traits of five populations,the order of coefficients of variation were node number〉plant height〉leaf width〉leaf length;the order of variation degrees of the populations from large to small was KQH,MD,JZ,ZK,TTG population.Results of principal component analysis suggested that the four traits were all factors led to the phenotypic differences among the populations of Leymus chinensis.Leymus chinensis of five populations were divided into three groups by cluster analysis,MD,JZ and TTG were classified as one group,KQH and ZK population were individually classified as one group.[Conclusion] Leymus chinensis had large-scale phenotypic variations and showed strong adaptability to different habitats,which was very important for selection,breeding of fine varieties and germplasm conservation.展开更多
[Objective] The study aimed at cloning PKR gene from Ctenopharyngodon idellus induced by PolyI:C in vitro,so as to provide foundation for study on the anti-virus genes of C.idellus.[Method] By referring to the PKR ge...[Objective] The study aimed at cloning PKR gene from Ctenopharyngodon idellus induced by PolyI:C in vitro,so as to provide foundation for study on the anti-virus genes of C.idellus.[Method] By referring to the PKR gene sequences of zebra fish(AJ852023.1) and Carassius auratus(AY293929.1) in Genbank,three pairs of degenerate primers were designed with Primer Premier 5.0 software;in vitro C.idellus kidney cells(CIK) were treated with 100 μg/ml of Poly I:C for 12,36 and 48 h,and then total RNA of the cells treated was extracted for amplifying the PKR gene by RT-PCR.[Result] The PKR gene was amplified from the cells treated with Poly I:C for 36 and 48 h,but not from the cells treated for 12 h;in addition,the expression level increased with the processing time.Part of the amplified sequence of C.idellus shared the homology of 100% and 81.48% with the sequences of carp and zebra fish separately.[Conclusion] Part of the PKR gene sequence was cloned successfully from C.idellus.Moreover,we have proved that PolyI:C induction is effective for PKR protein expression,which will provide reference for treating viral diseases of C.idellus.展开更多
Lectins and leghemoglobins in legumes play the important roles, respectively, in recognition of host plants to their own rhizobia, and lowering the oxygen partial pressure surround the bacteroids and protecting nitrog...Lectins and leghemoglobins in legumes play the important roles, respectively, in recognition of host plants to their own rhizobia, and lowering the oxygen partial pressure surround the bacteroids and protecting nitrogenase from oxygen in symbiotic nitrogen_fixing nodules.In order to investigate the non_leguminous recognition of rhizobial bacteria relating to nitrogen fixation, plant expression vectors containing pea lectin gene ( pl ) and Parasponia hemoglobin gene ( phb ) have been, respectively, constructed in a plasmid and the plasmid has been introduced into tobacco ( Nicotiana tabacum L.) using Agrobacterium tumefaciens (Smith et Townsend) Conn as a vehicle for transformation. PCR and Southern blot demonstrated that the two genes were integrated into the genome of the tobacco plants. Histochemical staining for GUS activity, Western blotting,and in situ hybridization of pea lectin showed that they were expressed at translational level in the plants. These results may provide a clue for exploring whether Rhizobium leguminosarum bv. viciae could extend its host range and make the transgenic tobacco plants have the possibility of being symbiotic, or associative to nitrogen fixation.展开更多
The gene encoded for tryptophan decarboxylase (TDC), which is the key enzyme in terpenoil indole alkaloids pathway, was targeted to different subcellular compartments and stably expressed in transgenic tobacco (Nicoti...The gene encoded for tryptophan decarboxylase (TDC), which is the key enzyme in terpenoil indole alkaloids pathway, was targeted to different subcellular compartments and stably expressed in transgenic tobacco (Nicotiana tabacum L.) plants at the levels detected by Western blot and tryptamine accumulation analysis. It was shown that the TDC was located in subcellular compartments, the chloroplasts and cytosol. The recombinant TDC targeted to chloroplasts and cytosol in tobacco plants was effectively expressed as soluble protein by Western blot analysis and enzymatic assay. The level of tryptamine accumulation in chloroplast was higher than that in cytosol and very low in vacuole and endoplasmic reticulum (ER) to be hardly detected by Western blot analysis. It was indicated that the highest amount of tryptamine was in chloroplasts, lower in endoplasmic reticula and the lowest in vacuoles as compared to those in wild type plants. The TDC targeted to different subcellular compartments of tobacco plants and its expression level were studied by different nucleotide sequences coding signal peptides at 5'-end of tdc gene in order to know the effects of the TDC in compartmentation on its functionality.展开更多
The presence of a thatch layer in established pastures could reduce the contact between broiler litter and soil, thus increasing the potential for surface runoff contamination with litter P. We conducted a laboratory ...The presence of a thatch layer in established pastures could reduce the contact between broiler litter and soil, thus increasing the potential for surface runoff contamination with litter P. We conducted a laboratory study to evaluate the effect of a thatch layer on the dynamics of water-soluble P in undisturbed cores taken from a pasture. Cores with and without a thatch layer received a surface application of broiler litter (5 thm-2) and were incubated at 25 oC for 56 d. The result showed that on the soil surface the contents of water soluble-P (39 kghm-2) of the cores with the thatch layer was higher than that (20 kghm-2) of the cores without the thatch layer. Therefore on well-established pastures fertilized with broiler litter, the presence of a thatch layer might lead to high concentrations of water-soluble P on the soil surface.展开更多
Strictosidine synthase (STR) is a key enzyme involved in the biosynthesis of terpenoid indole alkaloids (TIA) by condensing tryptamine and secologanin into strictosidine. The transgenic tobacco plants targeting STR to...Strictosidine synthase (STR) is a key enzyme involved in the biosynthesis of terpenoid indole alkaloids (TIA) by condensing tryptamine and secologanin into strictosidine. The transgenic tobacco plants targeting STR to subcellular compartments were established to express STR in chloroplast, vacuole and endoplasmic reticulum (ER) by the tobacco stable transformation. It was shown that STR was effectively expressed in the above subcellular compartments by Western blot analysis and STR enzymatic assay. In vitro , STR enzymatic assay was measured indirectly by fluorimetrically detecting depletion of tryptamine feeding on secologanin in the reaction mixture. The tryptamine were completely depleted by STR in the crude extract of leaves of transgenic tobacco plants targeting and expressing STR in the chloroplast, vacuole and ER, which ascertained the STR functionally targeted to the three subcellular compartments. To confirm STR correct targeting and expressing in chloroplast, the chloroplasts were isolated and the fractions of purified chloroplasts were analyzed by Western blot. The hypothesis of STR correct targeting to the chloroplast was tested. The results have implications on our understanding of the complex intracellular trafficking in metabolic intermediates of TIA biosynthesis.展开更多
A genomic DNA containing 5'-upstream region and complete open reading frame of a Gastrodia antifungal protein was isolated by screening of a genomic library from Gastrodia elata B1. To investigate the promoter act...A genomic DNA containing 5'-upstream region and complete open reading frame of a Gastrodia antifungal protein was isolated by screening of a genomic library from Gastrodia elata B1. To investigate the promoter activity, the 5'-flanking region - 1 157 lip upstream from the putative transcription start site was fused to the coding sequence of beta-glucuronidase (GUS) gene and transformed into Nicotiana tabacum. The strongest GUS activity was detected in the roots of transgenic tobacco, followed by stems. The leaves only showed a low GUS activity. Furthermore, the promoter established inducible expression pattern in transgenic tobacco upon fungus Trichoderma viride inoculation and jasmonic acid and salicylic acid treatments.展开更多
The copper-regulated gene expression system has been developed to control spacial and temporal expression of transgene in plant. It comprises two parts: (1) ace I gene encoding copper-responsive transcription factor u...The copper-regulated gene expression system has been developed to control spacial and temporal expression of transgene in plant. It comprises two parts: (1) ace I gene encoding copper-responsive transcription factor under the control of a constitutive or organ-specific promoter, and (2) a gene of interest under the control of a chimeric promoter consisting of the CaMV 35S (-90 to +8) promoter linked to the metal responsive element (MRE) carrying activating copper-metallothionein expression (ACE1)-binding sites. Here, the effectiveness of two different ACE1-binding cis -elements which derive from 5'-regulatory region of yeast metallothionein gene was investigated in transgenic tobacco (Nicotiana tabacum L. cv. W38). The results revealed that the MRE (-210 to -126) could increase the system inducibility by 50% - 100% compared with the previously reported MRE (-148 to -105). It is potential to use the copper-inducible system to control valuable gene traits in plant biotechnology.展开更多
[Objective] This study aimed to investigation the effects of straw covering and different types of potassium fertilizer on salinity accumulation in surface layer of tobacco-planted paddy soil in southern China. [Metho...[Objective] This study aimed to investigation the effects of straw covering and different types of potassium fertilizer on salinity accumulation in surface layer of tobacco-planted paddy soil in southern China. [Method] Tobacco variety ‘Yunyan87’ was used as the experimental material to investigate the effects of salinity accumulation in surface layer of tobacco-planted paddy soil on the growth and development of flue-cured tobacco using different types of potassium fertilizer and mulching cultivation methods. [Result] The results showed that K+ , Ca2+ , SO42and NO3-were the major salt ions in topsoil at different growth stages of flue-cured tobacco, Na + and Mg2+ contents were also relatively high at vigorous growth stage, indicating that these salt ions were easily accumulated in surface layer of soil; to be specific, the absolute increase of salt ion concentration showed a decreasing order of K+ SO42- NO3-Ca2+ Mg2+ Na+ Cl-, while the relative increase of salt ion concentration showed a decreasing order of Ca2+ K+ Na+ NO3-SO42-Mg2+ Cl-. At 60 d posttransplanting, total salt content in topsoil reached the minimum of 359.1 mg/kg in Treatment 2, total salt content in topsoil reached the maximum of 536.1 mg/kg in Treatment 5 (CK), which was significantly higher than that in other treatments. At 90 d post-transplanting, no significant difference was observed in total salt content among various treatments. At harvesting period, total salt content in topsoil reached the maximum of 3 278.4 mg/kg in Treatment 1, which was significantly higher than that in other treatments. Topsoil pH showed no significant differences among various treatments at three different periods, ranging from 5.39 to 5.59. Straw covering could effectively reduce salt content in topsoil, accelerate vigorous growth of tobacco, shorten vigorous growth period and increase plant height, leaf number and lead area; at vigorous growth stage, root vitality and root volume of tobacco were improved, but the yield and output value were relatively low. Major agronomic traits and yield of tobacco showed no significant difference among various treatments. Output value of tobacco reached the maximum of 24 196.8 yuan/hm2 in Treatment 3, which was significantly higher than that in other treatments. [Conclusion] Appropriate types and proportions of potassium fertilizer and straw covering can effectively reduce the total salt content in tobacco-planted paddy soil and increase the effective supply amount of K+ , Ca2+ , SO42-and NO3-, thereby promoting and improving the root vitality of tobacco, which is conducive to the growth and development of tobacco and will eventually enhance the yield, quality and economic benefits of flue-cured tobacco.展开更多
Cre site-specific recombinase-mediated DNA excision system was driven by the heat shock promoter Gmhsp17.5C. In this system, the DNA fragment with CaMV35S-GUS franked by two identical orientation loxp sites could be e...Cre site-specific recombinase-mediated DNA excision system was driven by the heat shock promoter Gmhsp17.5C. In this system, the DNA fragment with CaMV35S-GUS franked by two identical orientation loxp sites could be excised from the transgenic tobacco (Nicotiana tabacum L. cv. W38) by Cre expression under control of heat shock promoter. This transgenic system has been determined by quantitative PCR and showed Cre/lox mediated recombination efficiency. Results showed that 41% of DNA fragment with CaMV35S-GUS in the transgenic tobacco could be excised after a two-hour heat shock treatment. Based on several advantages of heat shock-inducible site-specific recombination system such as easy manipulation, sensitivity to heat shock and no background expression, it can be potentially used for inducible DNA manipulation in transgenic plant.展开更多
[Objective] The aim was to study the expression of cold resistant gene CAS19 of Gongnong No.2 Medicago sativa L. in tobacco. [Method] A pair of primers was designed according to nucleotide sequences of cold resistant ...[Objective] The aim was to study the expression of cold resistant gene CAS19 of Gongnong No.2 Medicago sativa L. in tobacco. [Method] A pair of primers was designed according to nucleotide sequences of cold resistant gene CAS19 of M. sativa,and then RT-PCR was used to amplify the protein gene of CAS19,which was then cloned into pMD18-T vector and subcloned into expression vector PBI121. The recombination expression plasmid PBCAS was constructed. And then it was transferred into tobacco genome via Agrobacterium,and Southern-blotting analysis was used for detecting transgenic plants. [Result] CAS19 gene was integrated into the tobacco genome and highly expressed. [Conclusion] This study had provided theoretical basis for further exploring the expression mechanism of cold resistant gene CAS19 in tobacco.展开更多
基金supported by the National Basic Research Program of China (2006CB400506)
文摘The modeling ability of a stand-alone version of the Simple Biosphere Model 2(SiB2) was tested mainly through diagnosing the simulated latent heat(LE),sensible heat(H),CO2 flux,and air temperature at the Tongyu field observation station(44°25'N,122°52'E,184 m elevation) of Coordinated Enhanced Observing Period(CEOP),where the land cover is cropland and grassland.In the whole year of 2003,the canopy height and the leaf area index was variable.During non-growth period,the surface would become bare,while during the growth period,the canopy height could reach 2.0 m high over cropland and 0.8 m high over grassland,respectively,and max leaf area index could reach 4.2 and 2.4,respectively.The model was initialized with measurement and driven by half-hourly atmospheric observations.The simulation values for 2003 were compared against measurements.Results show that the model is of a good ability of simulating the hourly latent heat(LE),sensible heat(H),CO2 flux and temperature during the growth period.Moreover,the daily LE,H and CO2 flux simulated by SiB2 could reflect their yearly change reasonably.However,the model may overestimate the H generally.
文摘Sex expression in Sagittaria guyanensis H.B.K. subsp. lappula (D. Don) Bojin is typically andromonoecious while the other species in the same genus are basically monoecious. The evolutionary advantages of male flowers and hermaphrodite flowers in S. guyanensis subsp. lappula were assessed by measuring sex allocation and pollen movements in two wild populations of the species. Two cultivated populations served as controls. The percentage of male flowers was very low in the two wild populations in Dongxiang, Jiangxi Province and Wuyishan, Fujian Province, viz., 2.48% and 0.96% respectively. In the two cultivated populations, male flower percentage significantly increased when the soil was of higher nutrient content. This indicates that the allocation to male versus female reproduction might change in response to environmental factors. Pollen production per male flower was 4.1 times higher than that of a hermaphrodite flower. The floral shape and size of male and hermaphrodite flowers were similar. No difference was observed between these dimorphological flowers in pollen germination rate in vitro and in the speed of pollen tube growth in vivo . Anthesis was only 4-5 h. Male flowers usually opened 0.5 h earlier than hermaphrodite flowers. An unexpected finding was that no pollen from the male flowers was found on the stigmas of the hermaphrodite flowers, in spite of the occasional visits by insects to both types of flowers in both wild and control populations. A consistent pattern of fruit development was found to exist in open pollinated flowers as well as in flowers that had been bagged. The sex ratios did not have significant influence on fruit set. Approximately 25% of the pistils in a gynoecium failed to develop into fruits because no pollen was deposited on them, indicating that the fruit set of this andromonoecious plant is mainly affected by pollen limitation rather than resource limitation. Reproduction in S. guyanensis subsp. lappula in the habitats was dependent on self_pollination in hermaphrodite flowers. The male flowers in this species might be a potential source of additional pollination and may facilitate cross_pollination. The fact that the flowers of monoecious species in Sagittaria pollinated by a wide diversity of insect visitors may contribute enormously to the diversification of sex expression in this genus.
基金Supported by National Natural Science Foundation of China(40971053)~~
文摘[Objective] This paper aimed at revealing the rules of phenotypic variation of Leymus chinensis in Zhalong wetlands and providing the scientific and theoretical bases for devising protection strategies of Leymus chinensis populations in Zhalong National Nature Reserve.[Method] Four phenotypic traits of five Leymus chinensis populations in Zhalong Wetlands were comparison and analysis using principal component analysis method and UPGMA cluster analysis method.[Result] There were significant differences among the four phenotypic traits of five populations,the order of coefficients of variation were node number〉plant height〉leaf width〉leaf length;the order of variation degrees of the populations from large to small was KQH,MD,JZ,ZK,TTG population.Results of principal component analysis suggested that the four traits were all factors led to the phenotypic differences among the populations of Leymus chinensis.Leymus chinensis of five populations were divided into three groups by cluster analysis,MD,JZ and TTG were classified as one group,KQH and ZK population were individually classified as one group.[Conclusion] Leymus chinensis had large-scale phenotypic variations and showed strong adaptability to different habitats,which was very important for selection,breeding of fine varieties and germplasm conservation.
基金Supported by National Natural Science Foundation of Zhejiang Province (Y3110432 )Huzhou Teachers College Science ResearchFoundation (2010YZ48)~~
文摘[Objective] The study aimed at cloning PKR gene from Ctenopharyngodon idellus induced by PolyI:C in vitro,so as to provide foundation for study on the anti-virus genes of C.idellus.[Method] By referring to the PKR gene sequences of zebra fish(AJ852023.1) and Carassius auratus(AY293929.1) in Genbank,three pairs of degenerate primers were designed with Primer Premier 5.0 software;in vitro C.idellus kidney cells(CIK) were treated with 100 μg/ml of Poly I:C for 12,36 and 48 h,and then total RNA of the cells treated was extracted for amplifying the PKR gene by RT-PCR.[Result] The PKR gene was amplified from the cells treated with Poly I:C for 36 and 48 h,but not from the cells treated for 12 h;in addition,the expression level increased with the processing time.Part of the amplified sequence of C.idellus shared the homology of 100% and 81.48% with the sequences of carp and zebra fish separately.[Conclusion] Part of the PKR gene sequence was cloned successfully from C.idellus.Moreover,we have proved that PolyI:C induction is effective for PKR protein expression,which will provide reference for treating viral diseases of C.idellus.
文摘Lectins and leghemoglobins in legumes play the important roles, respectively, in recognition of host plants to their own rhizobia, and lowering the oxygen partial pressure surround the bacteroids and protecting nitrogenase from oxygen in symbiotic nitrogen_fixing nodules.In order to investigate the non_leguminous recognition of rhizobial bacteria relating to nitrogen fixation, plant expression vectors containing pea lectin gene ( pl ) and Parasponia hemoglobin gene ( phb ) have been, respectively, constructed in a plasmid and the plasmid has been introduced into tobacco ( Nicotiana tabacum L.) using Agrobacterium tumefaciens (Smith et Townsend) Conn as a vehicle for transformation. PCR and Southern blot demonstrated that the two genes were integrated into the genome of the tobacco plants. Histochemical staining for GUS activity, Western blotting,and in situ hybridization of pea lectin showed that they were expressed at translational level in the plants. These results may provide a clue for exploring whether Rhizobium leguminosarum bv. viciae could extend its host range and make the transgenic tobacco plants have the possibility of being symbiotic, or associative to nitrogen fixation.
文摘The gene encoded for tryptophan decarboxylase (TDC), which is the key enzyme in terpenoil indole alkaloids pathway, was targeted to different subcellular compartments and stably expressed in transgenic tobacco (Nicotiana tabacum L.) plants at the levels detected by Western blot and tryptamine accumulation analysis. It was shown that the TDC was located in subcellular compartments, the chloroplasts and cytosol. The recombinant TDC targeted to chloroplasts and cytosol in tobacco plants was effectively expressed as soluble protein by Western blot analysis and enzymatic assay. The level of tryptamine accumulation in chloroplast was higher than that in cytosol and very low in vacuole and endoplasmic reticulum (ER) to be hardly detected by Western blot analysis. It was indicated that the highest amount of tryptamine was in chloroplasts, lower in endoplasmic reticula and the lowest in vacuoles as compared to those in wild type plants. The TDC targeted to different subcellular compartments of tobacco plants and its expression level were studied by different nucleotide sequences coding signal peptides at 5'-end of tdc gene in order to know the effects of the TDC in compartmentation on its functionality.
文摘The presence of a thatch layer in established pastures could reduce the contact between broiler litter and soil, thus increasing the potential for surface runoff contamination with litter P. We conducted a laboratory study to evaluate the effect of a thatch layer on the dynamics of water-soluble P in undisturbed cores taken from a pasture. Cores with and without a thatch layer received a surface application of broiler litter (5 thm-2) and were incubated at 25 oC for 56 d. The result showed that on the soil surface the contents of water soluble-P (39 kghm-2) of the cores with the thatch layer was higher than that (20 kghm-2) of the cores without the thatch layer. Therefore on well-established pastures fertilized with broiler litter, the presence of a thatch layer might lead to high concentrations of water-soluble P on the soil surface.
文摘Strictosidine synthase (STR) is a key enzyme involved in the biosynthesis of terpenoid indole alkaloids (TIA) by condensing tryptamine and secologanin into strictosidine. The transgenic tobacco plants targeting STR to subcellular compartments were established to express STR in chloroplast, vacuole and endoplasmic reticulum (ER) by the tobacco stable transformation. It was shown that STR was effectively expressed in the above subcellular compartments by Western blot analysis and STR enzymatic assay. In vitro , STR enzymatic assay was measured indirectly by fluorimetrically detecting depletion of tryptamine feeding on secologanin in the reaction mixture. The tryptamine were completely depleted by STR in the crude extract of leaves of transgenic tobacco plants targeting and expressing STR in the chloroplast, vacuole and ER, which ascertained the STR functionally targeted to the three subcellular compartments. To confirm STR correct targeting and expressing in chloroplast, the chloroplasts were isolated and the fractions of purified chloroplasts were analyzed by Western blot. The hypothesis of STR correct targeting to the chloroplast was tested. The results have implications on our understanding of the complex intracellular trafficking in metabolic intermediates of TIA biosynthesis.
文摘A genomic DNA containing 5'-upstream region and complete open reading frame of a Gastrodia antifungal protein was isolated by screening of a genomic library from Gastrodia elata B1. To investigate the promoter activity, the 5'-flanking region - 1 157 lip upstream from the putative transcription start site was fused to the coding sequence of beta-glucuronidase (GUS) gene and transformed into Nicotiana tabacum. The strongest GUS activity was detected in the roots of transgenic tobacco, followed by stems. The leaves only showed a low GUS activity. Furthermore, the promoter established inducible expression pattern in transgenic tobacco upon fungus Trichoderma viride inoculation and jasmonic acid and salicylic acid treatments.
文摘The copper-regulated gene expression system has been developed to control spacial and temporal expression of transgene in plant. It comprises two parts: (1) ace I gene encoding copper-responsive transcription factor under the control of a constitutive or organ-specific promoter, and (2) a gene of interest under the control of a chimeric promoter consisting of the CaMV 35S (-90 to +8) promoter linked to the metal responsive element (MRE) carrying activating copper-metallothionein expression (ACE1)-binding sites. Here, the effectiveness of two different ACE1-binding cis -elements which derive from 5'-regulatory region of yeast metallothionein gene was investigated in transgenic tobacco (Nicotiana tabacum L. cv. W38). The results revealed that the MRE (-210 to -126) could increase the system inducibility by 50% - 100% compared with the previously reported MRE (-148 to -105). It is potential to use the copper-inducible system to control valuable gene traits in plant biotechnology.
基金Supported by Project of Guangdong Zhongyan Industry Limited Liability Company[YYG15JO-QK(2011)-004]~~
文摘[Objective] This study aimed to investigation the effects of straw covering and different types of potassium fertilizer on salinity accumulation in surface layer of tobacco-planted paddy soil in southern China. [Method] Tobacco variety ‘Yunyan87’ was used as the experimental material to investigate the effects of salinity accumulation in surface layer of tobacco-planted paddy soil on the growth and development of flue-cured tobacco using different types of potassium fertilizer and mulching cultivation methods. [Result] The results showed that K+ , Ca2+ , SO42and NO3-were the major salt ions in topsoil at different growth stages of flue-cured tobacco, Na + and Mg2+ contents were also relatively high at vigorous growth stage, indicating that these salt ions were easily accumulated in surface layer of soil; to be specific, the absolute increase of salt ion concentration showed a decreasing order of K+ SO42- NO3-Ca2+ Mg2+ Na+ Cl-, while the relative increase of salt ion concentration showed a decreasing order of Ca2+ K+ Na+ NO3-SO42-Mg2+ Cl-. At 60 d posttransplanting, total salt content in topsoil reached the minimum of 359.1 mg/kg in Treatment 2, total salt content in topsoil reached the maximum of 536.1 mg/kg in Treatment 5 (CK), which was significantly higher than that in other treatments. At 90 d post-transplanting, no significant difference was observed in total salt content among various treatments. At harvesting period, total salt content in topsoil reached the maximum of 3 278.4 mg/kg in Treatment 1, which was significantly higher than that in other treatments. Topsoil pH showed no significant differences among various treatments at three different periods, ranging from 5.39 to 5.59. Straw covering could effectively reduce salt content in topsoil, accelerate vigorous growth of tobacco, shorten vigorous growth period and increase plant height, leaf number and lead area; at vigorous growth stage, root vitality and root volume of tobacco were improved, but the yield and output value were relatively low. Major agronomic traits and yield of tobacco showed no significant difference among various treatments. Output value of tobacco reached the maximum of 24 196.8 yuan/hm2 in Treatment 3, which was significantly higher than that in other treatments. [Conclusion] Appropriate types and proportions of potassium fertilizer and straw covering can effectively reduce the total salt content in tobacco-planted paddy soil and increase the effective supply amount of K+ , Ca2+ , SO42-and NO3-, thereby promoting and improving the root vitality of tobacco, which is conducive to the growth and development of tobacco and will eventually enhance the yield, quality and economic benefits of flue-cured tobacco.
文摘Cre site-specific recombinase-mediated DNA excision system was driven by the heat shock promoter Gmhsp17.5C. In this system, the DNA fragment with CaMV35S-GUS franked by two identical orientation loxp sites could be excised from the transgenic tobacco (Nicotiana tabacum L. cv. W38) by Cre expression under control of heat shock promoter. This transgenic system has been determined by quantitative PCR and showed Cre/lox mediated recombination efficiency. Results showed that 41% of DNA fragment with CaMV35S-GUS in the transgenic tobacco could be excised after a two-hour heat shock treatment. Based on several advantages of heat shock-inducible site-specific recombination system such as easy manipulation, sensitivity to heat shock and no background expression, it can be potentially used for inducible DNA manipulation in transgenic plant.
基金Supported by National High Technology Research and Development Program of China(2008AA10Z224)National Natural Science Foundation of China (30471229)~~
文摘[Objective] The aim was to study the expression of cold resistant gene CAS19 of Gongnong No.2 Medicago sativa L. in tobacco. [Method] A pair of primers was designed according to nucleotide sequences of cold resistant gene CAS19 of M. sativa,and then RT-PCR was used to amplify the protein gene of CAS19,which was then cloned into pMD18-T vector and subcloned into expression vector PBI121. The recombination expression plasmid PBCAS was constructed. And then it was transferred into tobacco genome via Agrobacterium,and Southern-blotting analysis was used for detecting transgenic plants. [Result] CAS19 gene was integrated into the tobacco genome and highly expressed. [Conclusion] This study had provided theoretical basis for further exploring the expression mechanism of cold resistant gene CAS19 in tobacco.