AIM: To transfer hepatitis E virus (HEV) ORF2 partial gene to tomato plants, to investigate its expression in transformants and the immunoactivity of expression products, and to explore the feasibility of developing a...AIM: To transfer hepatitis E virus (HEV) ORF2 partial gene to tomato plants, to investigate its expression in transformants and the immunoactivity of expression products, and to explore the feasibility of developing a new type of plantderived HEV oral vaccine.METHODS: Plant binary expression vector p1301E2,carrying a fragment of HEV open reading frame-2 (named HEV-E2), was constructed by linking the fragment to a constitutive CaMV35s promoter and nos terminator, then directly introduced into Agrobacterium tumefaciens EHA105. With leaf-disc method, tomato plants medicated by EHA105 were transformed and hygromycin-resistant plantlets were obtained in selective medium containing hygromycin. The presence and integration of foreign DNA in transgenic tomato genome were confirmed by Gus gene expression, PCR amplification and Southern dot blotting.The immunoactivity of recombinant protein extracted from transformed plants was examined by enzyme-linked immunosorbant assay (ELISA) using a monoclonal antibody specifically against HEV. ELISA was also used to estimate the recombinant protein content in leaves and fruits of the transformants.RESULTS: Seven positive lines of HEV-E2-transgenic tomato plants confirmed by PCR and Southern blotting were obtained and the immunoactivity of recombinant protein could be detected in extracts of transformants. The expression levels of recombinant protein were 61.22 ng/g fresh weight in fruits and 6.37-47.9 ng/g fresh weight in leaves of the transformants.CONCLUSION: HEV-E2 gene was correctly expressed in transgenic tomatoes and the recombinant antigen derived from them has normal immunoactivity. Transgenic tomatoes may hold a good promise for producing a new type of lowcost oral vaccine for hepatitis E virus.展开更多
The photosynthetic characteristics and ultrastructure of chloroplast of cucumber in solar-greenhouse were studied. The result showed that the photosynthetic rate (Pn), photosyntheticability (A350), carboxylation effic...The photosynthetic characteristics and ultrastructure of chloroplast of cucumber in solar-greenhouse were studied. The result showed that the photosynthetic rate (Pn), photosyntheticability (A350), carboxylation efficiency, light saturation point and light compensation pointall declined remarkably under low light density, indicating that the photosynthetic characteristicsof cucumber were closely related to light environment. Under low light density, the minimalfluorescence (Fo), alterable fluorescence (Fv), photochemical efficiency of PSⅡ(Fv/Fm), steadyfluorescence in light (Fs), maximal fluorescence (Fm) and actual efficiency of PSⅡ(φPSⅡ)etcincreased, indicating that the photochemical activity and efficiency for solar energy transformationenhanced, thus the light proportion used to electron transport also increased. The chlorophylla, b, a/b and carotenoid of shading leaves decreased. However, the depressed extent of Chl a andChl a/b were obviously larger than that of Chl b. The number of chloroplast and starch grainin cucumber leaves descended, but that of grana and lamella increased as a shaded result. Thesize of chloroplast and starch grain of shading leaves minished.展开更多
Using PCR degenerate primers, designed with reference to the sequences of the conserved amino acids of known expansins, to amplify cDNA fragments in litchi fruit by RT-PCR, two different cDNA fragments , named as Lc-E...Using PCR degenerate primers, designed with reference to the sequences of the conserved amino acids of known expansins, to amplify cDNA fragments in litchi fruit by RT-PCR, two different cDNA fragments , named as Lc-Exp1 and Lc-Exp2 , were cloned. Lc-Exp1 and Lc-Exp2 was respectively composed of 531 bp encoding 177 amino acids and 537 bp encoding 179 amino acids. Eight cysteine residues and three tryp-tophan residues, which is supposed to be the characteristics of expansins, are conserved in both Lc-Exp1 and c-Exp2. In addition, the homology between the two expansins is 71. 6% at nucleotide acid sequences and 76.3% at amino acid sequences. The homology of Lc-Exp1 with Fa-Exp2 or Pp-Exp1 was 92.7% or 92.1%, but that of Lc-Exp2 with Fa-Exp2 or Pp-Exp1 was only 77. 4% or 76.3% at amino acid sequences.展开更多
Influences of propylene treatment on fruit softening and ethylene biosynthesis of persimmon genotype, 'Hiratanenashi' were investigated. The treatment with propylene could accelerate the softening and enhance ...Influences of propylene treatment on fruit softening and ethylene biosynthesis of persimmon genotype, 'Hiratanenashi' were investigated. The treatment with propylene could accelerate the softening and enhance ethylene biosynthesis, with higher sensitivity of immature fruit to the propylene was consistent with mRNA increase derived from transcription of ACS and ACO genes. Furthermore, ethylene synthesis increase in immature fruits was controlled and regulated mainly by DK-ACS1, DK-ACS2, DK-ACO1 and DK-ACO2, but regulated only by DK-ACS1 and DK-ACO1 in mature fruits.展开更多
The photosynthetic rate (Pn) and carboxylation efficiency (CE) were observed to be the highest in mid-position leaves of cucumber in solar-greenhouse, second in upper and middle-lower position leaves, and lowest in lo...The photosynthetic rate (Pn) and carboxylation efficiency (CE) were observed to be the highest in mid-position leaves of cucumber in solar-greenhouse, second in upper and middle-lower position leaves, and lowest in lower-position leaves. The saturation light of the mid-position leaves was also the highest, while the photo compensation points of the upper, middle and lower position leaves decreased as the leaf-position descended. During the growth period, the Pn of most leaves enhanced as PFD increased. Pn curves of diurnal variation in different position leaves had single-peak which appeared at 12: 00 a. m. As the plant density increased, the PFD of different layer leaves decreased, especially of the lower position leaves. The effect of plant density on the Pn of the upper-position leaves was not visible, but on the light compensation points was obvious. As to lower position leaves, the Pn and saturation light decreased as the plant density increased, but the light compensation points were not obviously affected. Cucumber leaves had certain capacity of adaptation and adjustment to light intensity which expressed as the lower the PFD, the higher the apparent quantum yield (AQY). So the AQY increased as the leaf position descended and plant density increased.展开更多
Changes in carbohydrate, phenols, free amino acids and endogenous hormones in middle scales of Lilium davidii var.unicolor bulbs during the 101 days storage at 2, 6 and 10°C in moist sawdust were studied. The res...Changes in carbohydrate, phenols, free amino acids and endogenous hormones in middle scales of Lilium davidii var.unicolor bulbs during the 101 days storage at 2, 6 and 10°C in moist sawdust were studied. The results indicated that asthe storage time increased and the storage temperature delined, contents of starch and abscisic acid (ABA) decreasedmarkedly, and the level of total soluble sugar, phenols, gibberellic acid (GA3) and indole acetic acid (IAA) increasedsharply. In the first 34 days, the contents of the above substances changed most actively. Correlation analysis revealedthat the increase in content of total soluble sugar and phenols was respectively caused by activation of amylase andphenylalanine ammonia-lyase (PAL). During the storage, the content of free amino acids decreased, and the level ofarginine was the highest and changed most remarkably. According to the results of stepwise regression analysis and pathanalysis, we could primarily conclude that the metabolism of carbohydrates, phenols and free amino acids in the middlescales may be mainly regulated by endogenous GA3.展开更多
Studies on the reproduction and cytogenetic characterization of a primary amphidiploid Cucumis species C. hytivus Chen and Kirkbride (2n = 4x = 38) indicated that a more comprehensive cytogenetic analysis of this spec...Studies on the reproduction and cytogenetic characterization of a primary amphidiploid Cucumis species C. hytivus Chen and Kirkbride (2n = 4x = 38) indicated that a more comprehensive cytogenetic analysis of this species and its first selfed progeny would increase its potential utility in cucumber improvement. With tendrils used as source materials for mitotic analysis, chromosome numbers in all selfed progenies were 2n = 38, confirming chromosomal stability in this synthetic amphidiploid species. Detailed meiotic processes were described by comparing the primary and the selfed amphidiploids. Meiotic abnormalities, such as chromosome lagging, unequal separation, chromosome multi-polarization and polyads were observed frequently in all amphidiploid plants except for the selfed no.8, in which meiosis was arrested prior to metaphase Ⅰ. Generally, the frequency of multivalents was higher and the configurations were more complex in the selfed progenies, demonstrating a more extensive genetic exchange between cucumber and C. hystrix Chakr. Genome separation between cucumber and C. hystrix was observed through prophase Ⅰ to anaphase Ⅰ in both generations of the amphidiploids. Consequently, in addition to n = 19, a new gamete with n = 7 was produced, which was confirmed by the chromosome counts 2n = 14 in the backcrossing progenies from cucumber × amphidiploid mating. Fertility varied among the selfed amphidiploid plants. The selfed plant no.1 was found to have an improved fertility (e.g., pollen staining ability 40.8% and 25.6 seeds per fruit) and then was used as source germplasm in further introgression and gene exchange experiments.展开更多
We had investigated about the situation about garden-making of Changzhou City twice where soil was serious saline and alkaline. We had also investigated the natural environment of the city. Based on these cases, we di...We had investigated about the situation about garden-making of Changzhou City twice where soil was serious saline and alkaline. We had also investigated the natural environment of the city. Based on these cases, we discussed the possible measurements about landscaping project under these conditions, so that we can give out the possible project measurements for the same area.展开更多
The 1216bp5’upstream region of the gene encoding the class Ⅲ chitinase VCH3 was isolated from grapevine(Vitis amurensis Rubr．)(Genbank accession number AF441123)and two inverse salicylic acid(SA)responsive cis-acti...The 1216bp5’upstream region of the gene encoding the class Ⅲ chitinase VCH3 was isolated from grapevine(Vitis amurensis Rubr．)(Genbank accession number AF441123)and two inverse salicylic acid(SA)responsive cis-acting motifs(TGACG)were found at-1181bp and-293 bp upstream of the transcriptional start site．respectively．To characterize the vcH3promoter，four chimeric constructs varied in the length of promoter fragments from-1187bp，-892bp，-589bp and-276bpto+7bp relative to the transcriptional start site were placed to the upstream of the β-glucuronidase(GUS)coding region and transferred to Nicotlana tobacum L．CV．NC89 by Agrobacterium tumefaciens-mediated leaf discs transformation．The functional properties of each promoter fragment were examined by fluorometric and histochemical analysis of GUS activity in the transgenic tobacco root treated withSA．The VCH3(-276)GUS construct．containing only the TATA and CAAT boxes was shown to have little inducibility upontreatment with SA．However，the similarly higher level of GUS expression was observed in the VCH3(-589) GUS or VCH3(-892) GUS transgenic plants with only one cis-acting motif,while the most abundance of GUS expression was found in the full-1ength promoter(-1187bpto+7bp)with two cis-acting motifs．The seresults indicated that the twocis-acting motifs werere quired for the maximal expression of the GUS reporter gene by SA induction．In addition，the histochemical analysis of GUS activity showed that the four VCH3 promoter fragments were more active in vascular tissue than that in outer and inner cortexes of the transgenic tobacco roots treated by SA，suggesting that the region involved in vascular tissue-specific expression of VCH3 promoter upon SA inducibility appears to belocated between positions-276 bp and+7bp relative to the transcriptional start site．In general，these results indicate a potential use for the SA induction of VCH3 promoter in genetic engineering．展开更多
基金a grant from the Natural Science Foundation of Fujian Province,No.C9910004Xiamen Kaili Biologic Product Limited Company
文摘AIM: To transfer hepatitis E virus (HEV) ORF2 partial gene to tomato plants, to investigate its expression in transformants and the immunoactivity of expression products, and to explore the feasibility of developing a new type of plantderived HEV oral vaccine.METHODS: Plant binary expression vector p1301E2,carrying a fragment of HEV open reading frame-2 (named HEV-E2), was constructed by linking the fragment to a constitutive CaMV35s promoter and nos terminator, then directly introduced into Agrobacterium tumefaciens EHA105. With leaf-disc method, tomato plants medicated by EHA105 were transformed and hygromycin-resistant plantlets were obtained in selective medium containing hygromycin. The presence and integration of foreign DNA in transgenic tomato genome were confirmed by Gus gene expression, PCR amplification and Southern dot blotting.The immunoactivity of recombinant protein extracted from transformed plants was examined by enzyme-linked immunosorbant assay (ELISA) using a monoclonal antibody specifically against HEV. ELISA was also used to estimate the recombinant protein content in leaves and fruits of the transformants.RESULTS: Seven positive lines of HEV-E2-transgenic tomato plants confirmed by PCR and Southern blotting were obtained and the immunoactivity of recombinant protein could be detected in extracts of transformants. The expression levels of recombinant protein were 61.22 ng/g fresh weight in fruits and 6.37-47.9 ng/g fresh weight in leaves of the transformants.CONCLUSION: HEV-E2 gene was correctly expressed in transgenic tomatoes and the recombinant antigen derived from them has normal immunoactivity. Transgenic tomatoes may hold a good promise for producing a new type of lowcost oral vaccine for hepatitis E virus.
文摘The photosynthetic characteristics and ultrastructure of chloroplast of cucumber in solar-greenhouse were studied. The result showed that the photosynthetic rate (Pn), photosyntheticability (A350), carboxylation efficiency, light saturation point and light compensation pointall declined remarkably under low light density, indicating that the photosynthetic characteristicsof cucumber were closely related to light environment. Under low light density, the minimalfluorescence (Fo), alterable fluorescence (Fv), photochemical efficiency of PSⅡ(Fv/Fm), steadyfluorescence in light (Fs), maximal fluorescence (Fm) and actual efficiency of PSⅡ(φPSⅡ)etcincreased, indicating that the photochemical activity and efficiency for solar energy transformationenhanced, thus the light proportion used to electron transport also increased. The chlorophylla, b, a/b and carotenoid of shading leaves decreased. However, the depressed extent of Chl a andChl a/b were obviously larger than that of Chl b. The number of chloroplast and starch grainin cucumber leaves descended, but that of grana and lamella increased as a shaded result. Thesize of chloroplast and starch grain of shading leaves minished.
文摘Using PCR degenerate primers, designed with reference to the sequences of the conserved amino acids of known expansins, to amplify cDNA fragments in litchi fruit by RT-PCR, two different cDNA fragments , named as Lc-Exp1 and Lc-Exp2 , were cloned. Lc-Exp1 and Lc-Exp2 was respectively composed of 531 bp encoding 177 amino acids and 537 bp encoding 179 amino acids. Eight cysteine residues and three tryp-tophan residues, which is supposed to be the characteristics of expansins, are conserved in both Lc-Exp1 and c-Exp2. In addition, the homology between the two expansins is 71. 6% at nucleotide acid sequences and 76.3% at amino acid sequences. The homology of Lc-Exp1 with Fa-Exp2 or Pp-Exp1 was 92.7% or 92.1%, but that of Lc-Exp2 with Fa-Exp2 or Pp-Exp1 was only 77. 4% or 76.3% at amino acid sequences.
基金funded by the National Natural Science Foundation of China(30170662).
文摘Influences of propylene treatment on fruit softening and ethylene biosynthesis of persimmon genotype, 'Hiratanenashi' were investigated. The treatment with propylene could accelerate the softening and enhance ethylene biosynthesis, with higher sensitivity of immature fruit to the propylene was consistent with mRNA increase derived from transcription of ACS and ACO genes. Furthermore, ethylene synthesis increase in immature fruits was controlled and regulated mainly by DK-ACS1, DK-ACS2, DK-ACO1 and DK-ACO2, but regulated only by DK-ACS1 and DK-ACO1 in mature fruits.
文摘The photosynthetic rate (Pn) and carboxylation efficiency (CE) were observed to be the highest in mid-position leaves of cucumber in solar-greenhouse, second in upper and middle-lower position leaves, and lowest in lower-position leaves. The saturation light of the mid-position leaves was also the highest, while the photo compensation points of the upper, middle and lower position leaves decreased as the leaf-position descended. During the growth period, the Pn of most leaves enhanced as PFD increased. Pn curves of diurnal variation in different position leaves had single-peak which appeared at 12: 00 a. m. As the plant density increased, the PFD of different layer leaves decreased, especially of the lower position leaves. The effect of plant density on the Pn of the upper-position leaves was not visible, but on the light compensation points was obvious. As to lower position leaves, the Pn and saturation light decreased as the plant density increased, but the light compensation points were not obviously affected. Cucumber leaves had certain capacity of adaptation and adjustment to light intensity which expressed as the lower the PFD, the higher the apparent quantum yield (AQY). So the AQY increased as the leaf position descended and plant density increased.
基金This work was supported by the National Natural Science Foundation of China(30400307).
文摘Changes in carbohydrate, phenols, free amino acids and endogenous hormones in middle scales of Lilium davidii var.unicolor bulbs during the 101 days storage at 2, 6 and 10°C in moist sawdust were studied. The results indicated that asthe storage time increased and the storage temperature delined, contents of starch and abscisic acid (ABA) decreasedmarkedly, and the level of total soluble sugar, phenols, gibberellic acid (GA3) and indole acetic acid (IAA) increasedsharply. In the first 34 days, the contents of the above substances changed most actively. Correlation analysis revealedthat the increase in content of total soluble sugar and phenols was respectively caused by activation of amylase andphenylalanine ammonia-lyase (PAL). During the storage, the content of free amino acids decreased, and the level ofarginine was the highest and changed most remarkably. According to the results of stepwise regression analysis and pathanalysis, we could primarily conclude that the metabolism of carbohydrates, phenols and free amino acids in the middlescales may be mainly regulated by endogenous GA3.
基金This research was partially supported by the Trans-century Training Program Foundation for the Talents by the State Education Commission of China to Dr.Chen Jinfeng,by the National Natural Science Founda-tion of China(301 70644 and 30470120)by National Hi-Tech R&D Program(2002AA241251 and 2004 AA241120)by Tang's Cornell-China Scholar Program and by Pickle Seed Research Foundation of PPI.
文摘Studies on the reproduction and cytogenetic characterization of a primary amphidiploid Cucumis species C. hytivus Chen and Kirkbride (2n = 4x = 38) indicated that a more comprehensive cytogenetic analysis of this species and its first selfed progeny would increase its potential utility in cucumber improvement. With tendrils used as source materials for mitotic analysis, chromosome numbers in all selfed progenies were 2n = 38, confirming chromosomal stability in this synthetic amphidiploid species. Detailed meiotic processes were described by comparing the primary and the selfed amphidiploids. Meiotic abnormalities, such as chromosome lagging, unequal separation, chromosome multi-polarization and polyads were observed frequently in all amphidiploid plants except for the selfed no.8, in which meiosis was arrested prior to metaphase Ⅰ. Generally, the frequency of multivalents was higher and the configurations were more complex in the selfed progenies, demonstrating a more extensive genetic exchange between cucumber and C. hystrix Chakr. Genome separation between cucumber and C. hystrix was observed through prophase Ⅰ to anaphase Ⅰ in both generations of the amphidiploids. Consequently, in addition to n = 19, a new gamete with n = 7 was produced, which was confirmed by the chromosome counts 2n = 14 in the backcrossing progenies from cucumber × amphidiploid mating. Fertility varied among the selfed amphidiploid plants. The selfed plant no.1 was found to have an improved fertility (e.g., pollen staining ability 40.8% and 25.6 seeds per fruit) and then was used as source germplasm in further introgression and gene exchange experiments.
文摘We had investigated about the situation about garden-making of Changzhou City twice where soil was serious saline and alkaline. We had also investigated the natural environment of the city. Based on these cases, we discussed the possible measurements about landscaping project under these conditions, so that we can give out the possible project measurements for the same area.
文摘The 1216bp5’upstream region of the gene encoding the class Ⅲ chitinase VCH3 was isolated from grapevine(Vitis amurensis Rubr．)(Genbank accession number AF441123)and two inverse salicylic acid(SA)responsive cis-acting motifs(TGACG)were found at-1181bp and-293 bp upstream of the transcriptional start site．respectively．To characterize the vcH3promoter，four chimeric constructs varied in the length of promoter fragments from-1187bp，-892bp，-589bp and-276bpto+7bp relative to the transcriptional start site were placed to the upstream of the β-glucuronidase(GUS)coding region and transferred to Nicotlana tobacum L．CV．NC89 by Agrobacterium tumefaciens-mediated leaf discs transformation．The functional properties of each promoter fragment were examined by fluorometric and histochemical analysis of GUS activity in the transgenic tobacco root treated withSA．The VCH3(-276)GUS construct．containing only the TATA and CAAT boxes was shown to have little inducibility upontreatment with SA．However，the similarly higher level of GUS expression was observed in the VCH3(-589) GUS or VCH3(-892) GUS transgenic plants with only one cis-acting motif,while the most abundance of GUS expression was found in the full-1ength promoter(-1187bpto+7bp)with two cis-acting motifs．The seresults indicated that the twocis-acting motifs werere quired for the maximal expression of the GUS reporter gene by SA induction．In addition，the histochemical analysis of GUS activity showed that the four VCH3 promoter fragments were more active in vascular tissue than that in outer and inner cortexes of the transgenic tobacco roots treated by SA，suggesting that the region involved in vascular tissue-specific expression of VCH3 promoter upon SA inducibility appears to belocated between positions-276 bp and+7bp relative to the transcriptional start site．In general，these results indicate a potential use for the SA induction of VCH3 promoter in genetic engineering．
