The possible physiological mechanism of enhancement of cold tolerance by salicylic acid (SA) in banana seedlings ( Musa acuminata cv. Williams 8188) was explored. Measurements of leakage electrolyte after 2 d of re...The possible physiological mechanism of enhancement of cold tolerance by salicylic acid (SA) in banana seedlings ( Musa acuminata cv. Williams 8188) was explored. Measurements of leakage electrolyte after 2 d of recovery at 30/22 ℃ (day/night) following 3 d of cold stress at 7 ℃ showed that pretreatment with hydroponic solution containing SA 0.3-0.9 mmol/L as foliar spray under normal growth conditions (30/22 ℃) could significantly enhance cold tolerance of banana plants. The highest enhancing effect of SA occurred at 0.5 mmol/L and it showed the lowest leakage rate of electrolyte or smaller leaf wilting area after 2 d of recovery at normal temperature from 3 d of 7 ℃ or 5 ℃ cold stress. Higher concentrations (≥2.5 mmol/L) of SA, however, caused more electrolyte leakage, indicating that they aggravated chilling damage. Enhanced cold tolerance by SA could be related to H 2O 2 metabolism. Compared with water_treated seedlings (control), SA 0.5 mmol/L treatment inhibited activities of catalase (CAT) and ascorbate peroxidase (APX), increased peroxidase (POX) activity, but did not affect the activity of superoxide dismutase (SOD) under normal growth conditions, and these changes might lead to an accumulation of H 2O 2, whereas SA pretreatment enhanced the activities of CAT and APX, and reduced the increase in productions of H 2O 2 and thiobarbituric acid_reaction substances (TBARS) during subsequent 7 ℃ cold stress and recovery periods. Exogenous H 2O 2 treatments (1.5 -2.5 mmol/L) also increased cold tolerance of banana seedlings. Furthermore, pretreatment of banana seedlings with dimethylthiourea (a trap for H 2O 2) significantly inhibited cold tolerance induced by SA. These results suggested that endogenous H 2O 2 may be required for SA_enhanced cold tolerance. The significance of the interaction of SA, H 2O 2 and H 2O 2_metabolizing enzymes during cold stress has been discussed.展开更多
Camptotheca acuminata Decaisne is a tree unique to China, producing terpenoid indole alkaloid (TIA), camptothecin (CPT), and 10-hydroxycamptothecin (HCPT), which possesses strong anti-cancer bioactivity. The dynamics ...Camptotheca acuminata Decaisne is a tree unique to China, producing terpenoid indole alkaloid (TIA), camptothecin (CPT), and 10-hydroxycamptothecin (HCPT), which possesses strong anti-cancer bioactivity. The dynamics of HCPT and CPT during seed maturation, seed germination, postgerminative development and daily growth were measured by High Performance Liquid Chromatography (HPLC). This article provides some evidence for presenting the theory that each characteristic of HCPT and CPT accumulation is under developmental regulation and then attempt to elucidate the metabolic relationships between them. HCPT accumulates particularly in young tissues and organs and is relatively unstable, while the distribution of CPT is more ubiquitous and stable. Their different distribution properties suggest that HCPT and CPT are differentially regulated and play distinct roles:during development.展开更多
Objective To investigate the efficacy and safety of photodynamic therapy （PDT） with topical 5-aminolaevulinic acid （ALA） on cervical condylomata acuminata. Methods Patients with cervical condylomata （n=30） were...Objective To investigate the efficacy and safety of photodynamic therapy （PDT） with topical 5-aminolaevulinic acid （ALA） on cervical condylomata acuminata. Methods Patients with cervical condylomata （n=30） were allocated into primary and recurrent group, and were given topical ALA under occlusive dressing for 3 hours followed by irradiation with semiconductor laser at a dose of 100 Jcm 2 and a power of 100 roW. The treatment was repeated 7 days later if the lesion was not completely removed after the first treatment. Complete response rate and recurrence rate of wart lesions as well as rate of adverse reaction were analyzed. Results The total complete response rate of PDT was 100% and the total recurrence rate was 5% after 3 months of follow-up. Recurrence rate of recurrent group was significantly lower than that of prior managements （100%, P〈0.01）. The side effects of PDT in patients mainly included mild burning and/or stinging restricted to the illuminated areas, and was significant lower than their own control （25% vs. 100%, P〈0.05）. Conclusion Compared with conventional therapies, topical application of ALA-PDT is a simple, effective, safe, well-tolerated, and low recurrence rate treatment for cervical condylomata acuminata.展开更多
In order to investigate the correlation between the expression of the apoptotic regulatory proteins (Fas, Bcl 2) in peripheral blood lymphocytes (PBLC) and the level of IFN γ and IL 4 in serum of the patients with...In order to investigate the correlation between the expression of the apoptotic regulatory proteins (Fas, Bcl 2) in peripheral blood lymphocytes (PBLC) and the level of IFN γ and IL 4 in serum of the patients with condyloma acuminata (CA) in the immune pathogenesis of CA, indirect immunofluorescence labeling method of flow cytometer and solid sandwich ELISA method were performed for detecting the expression of Fas, Bcl 2 in PBLC and the level of IFN γ and IL 4 in serum of 60 cases of CA. The results showed the expression level of Fas in PBLC of CA was significantly higher than in the normal control group, but the expression level of Bcl 2 was significantly lower (both P< 0.01). The level of IFN γ in serum of CA was significantly lower than in the normal control group ( P< 0.01), but IL 4 was significantly lower (both P< 0.01). The expression of Fas in PBLC had a negative correlation with the level of IFN γ in serum of patients with CA, but had a positive correlation with the level of IL 4; The expression of Bcl 2 had a positive correlation with the level of IFN γ, but had a negative correlation with the level of IL 4. All the correlation coefficients had significant differerce by t test ( P< 0.01). It was suggested abnormal apoptosis in PBLC, the suppressed secretion of the THl associated cytokines (eg: IFN γ) and the increased secretion of the TH2 asssociated cytokines (eg: IL 4) existed in the patients with CA and might play an important role in the immune pathogenesis of CA.展开更多
The traditional culture-dependent plate counting and culture-independent small-subunit-ribosomal RNA gene-targeted molecular techniques, Single-Strand Conformation Polymorphism (SSCP) and ter-minal Restriction Fragmen...The traditional culture-dependent plate counting and culture-independent small-subunit-ribosomal RNA gene-targeted molecular techniques, Single-Strand Conformation Polymorphism (SSCP) and ter-minal Restriction Fragment Length Polymorphism (tRFLP) combined with 16S rDNA clone library were adopted to investigate the impacts of secretion from Camptotheca acuminata (abbreviated to Ca) roots on the quantities and structure of eukaryotic microbes and bacteria in the rhizosphere, and the possi-bility that Ca controls exotic invasive plant Eupatorium adenophorum (Ea). The counting results indi-cated that the number of bacteria increased in turn in rhizospheres of Ea, Ca-Ea mixed culture and Ca, while that of eukaryotic microbes decreased. PCR-SSCP profiles showed eukaryotic microbial bands (corresponding to biodiversity) in rhizosphere of Ea were more complex than those of Ca and CE. Meristolohmannia sp., Termitomyces sp. and Rhodophyllus sp. were the dominant populations in the rhizosphere of Ca. Bacterial terminal restriction fragments (TRFs) profiles showed no difference among three kinds of rhizospheres, and the sequences of the 16S rDNA clone library from Ca rhizospheres were distributed in 10 known phyla, in which phylum Proteobacteria were the absolute dominant group and accounted for 24.71% of the cloned sequences (δ-Proteobacteria accounted for up to 17.65%), and phyla Acidobacteria and Bacteroidetes accounted for 16.47% and 10.59% of the cloned sequences, respectively. In addition, high performance liquid chromatography detected a trace amount of camp-tothecin and hydroxycamptothecin in the rhizospheric soil of Ca and CE, but examined neither camp-tothecin nor hydroxycamptothecin in rhizospheric soil of Ea. Therefore, invasion and diffusion of Ea evidently depended on distinguishing the eukaryotic community structure, but not on that of the bac-terial pattern. Ca was able to alter the eukaryotic community structure of invasive Ea by secreting camptothecin and hydroxycamptothecin into rhizospheres, and may bene展开更多
Camptotheca acuminata produces camptothecin(CPT),a monoterpene indole alkaloid(MIA)that is widely used in the treatment of lung,colorectal,cervical,and ovarian cancers.Its biosynthesis pathway has attracted significan...Camptotheca acuminata produces camptothecin(CPT),a monoterpene indole alkaloid(MIA)that is widely used in the treatment of lung,colorectal,cervical,and ovarian cancers.Its biosynthesis pathway has attracted significant attention,but the regulation of CPT biosynthesis by the APETALA2/ethylene-responsive factor(AP2/ERF)transcription factors(TFs)remains unclear.In this study,a systematic analysis of the AP2/ERF TFs family in C.acuminata was performed,including phylogeny,gene structure,conserved motifs,and gene expression profiles in different tissues and organs(immature bark,cotyledons,young flower,immature fruit,mature fruit,mature leaf,roots,upper stem,and lower stem)of C.acuminata.A total of 198 AP2/ERF genes were identified and divided into five relatively conserved subfamilies,including AP2(26 genes),DREB(61 genes),ERF(92 genes),RAV(18 genes),and Soloist(one gene).The combination of gene expression patterns in different C.acuminata tissues and organs,the phylogenetic tree,the co-expression analysis with biosynthetic genes,and the analysis of promoter sequences of key enzymes genes involved in CPT biosynthesis pathways revealed that eight AP2/ERF TFs in C.acuminata might be involved in CPT synthesis regulation,which exhibit relatively high expression levels in the upper stem or immature bark.Among these,four genes(Cac AP2/ERF123,Cac AP2/ERF125,Cac AP2/ERF126,and Cac AP2/ERF127)belong to the ERF–B2 subgroup;two genes(Cac AP2/ERF149 and Cac AP2/ERF152)belong to the ERF–B3 subgroup;and two more genes(Cac AP2/ERF095 and Cac AP2/ERF096)belong to the DREB–A6 subgroup.These results provide a foundation for future functional characterization of the AP2/ERF genes to enhance the biosynthesis of CPT compounds of C.acuminata.展开更多
Plants interact with their environment by producing a diverse array of secondary metabolites, one of which is alkaloid. In this study, alkaloids, including camptothecin (CPT) and 10-hydroxycamptothecin (HCPT), malondi...Plants interact with their environment by producing a diverse array of secondary metabolites, one of which is alkaloid. In this study, alkaloids, including camptothecin (CPT) and 10-hydroxycamptothecin (HCPT), malondialdehyde (MDA) and chlorophyll contents were measured during heat shock in seedlings of Camptotheca acuminata Decaisne unique to China. Responses of different tissues, including young leaves, old leaves, buds and barks, to heat shock were examined in alkaloid changes. CPT and HCPT concentrations reached their peak values separately at 38 degreesC and 40 degreesC, which were below the lethal heat-shock temperature indicated by MDA and chlorophyll, and their great changes took place in young leaves. These results indicated that CPT and HCPT were involved in the C acuminata resistance against heat shock from its environment. Furthermore, plant rigidly observed the cost-benefit principle and mobilized and allocated limited alkaloid sources to young and reproductive tissues preferentially. In addition, HCPT displayed well-regulated changes during incubation at sublethal temperature, and this indicated that HCPT might play a more positively defensive role in enhancement of plant thermotolerance than CPT does.展开更多
Axillary buds from 3-yr.-old seedlings of Camptotheca acuminata in the greenhouse were cultured on the different basal media with different concentrations of growth regulators for shoot regeneration for studying the e...Axillary buds from 3-yr.-old seedlings of Camptotheca acuminata in the greenhouse were cultured on the different basal media with different concentrations of growth regulators for shoot regeneration for studying the effects of different basal media, different concen- trations of growth regulators (BA or TDZ), sucrose, agar and pH value on shoot regeneration from axillary bud. The results showed that B5 and WPM media were the optimal basal media and the optimal phyotohormone was BA of 1.0 mg/L or TDZ of 0.1mg/L; The concentrations of sucrose of 30g/L and agar of 6g/L were most suitable for the shoot regeneration; pH value from 5.8 to 6.6 were broadly effective, but the best at pH 5.8.展开更多
Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi （AMF）, Acaulospora m...Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi （AMF）, Acaulospora mellea, Glomus diaphanum and Sclerocystis sinuosa.. The height, biomass, and absorptions of nitrogen and phosphorus of C. acuminata seedlings inoculated with AMF were investigated. The results showed that the formation of AM promoted the height growth and biomass accumulation of seedlings significantly and improved the absorption of phosphorus in seedlings. The height and biomass of mycorrhizal seedlings were 1.2 and 1.6 times higher than those of the non-mycorrhizal seedlings. The absorption of nitrogen was less influenced by the formation of AM. The nitrogen content in mycorrhizal seedling was equal to that of non-mycorrhizal seedlings. Compared with non-mycorrhizal seedlings, the nitrogen content of mycorrhizal seedlings inoculated with A. mellea changed considerably in the root, stem and leaves. The difference in nitrogen content was not significant between mycorrhizal seedlings inoculated with G. diaphanum and S. sinuosa. The AM formation stimulated the absorption of phosphorus, especially in roots, and also changed the allocation of nitrogen and phosphorus in different organs of seedlings. Compared with non-mycorrhizal seedlings, the ratio of nitrogen and phosphorus in mycorrhizal roots increased, but reduced in stem and leaves.展开更多
Objective： Chilling tolerance of salicylic acid （SA） in banana seedlings （Musa acuminata cv., Williams 8818） was investigated by changes in ultrastructure in this study. Methods： Light and electron microscope ob...Objective： Chilling tolerance of salicylic acid （SA） in banana seedlings （Musa acuminata cv., Williams 8818） was investigated by changes in ultrastructure in this study. Methods： Light and electron microscope observation. Results： Pretreatment with 0.5 mmol/L SA under normal growth conditions （30/22 ℃） by foliar spray and root irrigation resulted in many changes in ultrastructure of banana cells, such as cells separation from palisade parenchymas, the appearance of crevices in cell walls, the swelling of grana and stromal thylakoids, and a reduction in the number of starch granules. These results implied that SA treatment at 30/22 ℃ could be a type of stress. During 3 d of exposure to 7 ℃ chilling stress under low light, however, cell ultrastructure of SA-pretreated banana seedlings showed less deterioration than those of control seedlings （distilled water-pretreated）. Conclusion： SA could provide some protection for cell structure of chilling-stressed banana seedling.展开更多
The determination method of 10-hydroxycamptothecin in Camptotheca acuminata fruits by high-performance liquid chromatogram (HPLC) was studied. The HPLC analysis was performed on a HIQ sil C18(4.6×250 mm) column w...The determination method of 10-hydroxycamptothecin in Camptotheca acuminata fruits by high-performance liquid chromatogram (HPLC) was studied. The HPLC analysis was performed on a HIQ sil C18(4.6×250 mm) column with mobile phase of acetonitrilewater (3:7, V:V), flow rate 1 mLmin-1 and UV detective wavelength 266 nm. Extracting 10-hydroxycamptothecin by ultrasonic method from fruits of C. acuminata to prepare samples for analysis was systematically discussed. The optimal extraction condition was carried out by 60% alcohol solution at 60℃ for 50 minutes.展开更多
文摘The possible physiological mechanism of enhancement of cold tolerance by salicylic acid (SA) in banana seedlings ( Musa acuminata cv. Williams 8188) was explored. Measurements of leakage electrolyte after 2 d of recovery at 30/22 ℃ (day/night) following 3 d of cold stress at 7 ℃ showed that pretreatment with hydroponic solution containing SA 0.3-0.9 mmol/L as foliar spray under normal growth conditions (30/22 ℃) could significantly enhance cold tolerance of banana plants. The highest enhancing effect of SA occurred at 0.5 mmol/L and it showed the lowest leakage rate of electrolyte or smaller leaf wilting area after 2 d of recovery at normal temperature from 3 d of 7 ℃ or 5 ℃ cold stress. Higher concentrations (≥2.5 mmol/L) of SA, however, caused more electrolyte leakage, indicating that they aggravated chilling damage. Enhanced cold tolerance by SA could be related to H 2O 2 metabolism. Compared with water_treated seedlings (control), SA 0.5 mmol/L treatment inhibited activities of catalase (CAT) and ascorbate peroxidase (APX), increased peroxidase (POX) activity, but did not affect the activity of superoxide dismutase (SOD) under normal growth conditions, and these changes might lead to an accumulation of H 2O 2, whereas SA pretreatment enhanced the activities of CAT and APX, and reduced the increase in productions of H 2O 2 and thiobarbituric acid_reaction substances (TBARS) during subsequent 7 ℃ cold stress and recovery periods. Exogenous H 2O 2 treatments (1.5 -2.5 mmol/L) also increased cold tolerance of banana seedlings. Furthermore, pretreatment of banana seedlings with dimethylthiourea (a trap for H 2O 2) significantly inhibited cold tolerance induced by SA. These results suggested that endogenous H 2O 2 may be required for SA_enhanced cold tolerance. The significance of the interaction of SA, H 2O 2 and H 2O 2_metabolizing enzymes during cold stress has been discussed.
文摘Camptotheca acuminata Decaisne is a tree unique to China, producing terpenoid indole alkaloid (TIA), camptothecin (CPT), and 10-hydroxycamptothecin (HCPT), which possesses strong anti-cancer bioactivity. The dynamics of HCPT and CPT during seed maturation, seed germination, postgerminative development and daily growth were measured by High Performance Liquid Chromatography (HPLC). This article provides some evidence for presenting the theory that each characteristic of HCPT and CPT accumulation is under developmental regulation and then attempt to elucidate the metabolic relationships between them. HCPT accumulates particularly in young tissues and organs and is relatively unstable, while the distribution of CPT is more ubiquitous and stable. Their different distribution properties suggest that HCPT and CPT are differentially regulated and play distinct roles:during development.
文摘Objective To investigate the efficacy and safety of photodynamic therapy （PDT） with topical 5-aminolaevulinic acid （ALA） on cervical condylomata acuminata. Methods Patients with cervical condylomata （n=30） were allocated into primary and recurrent group, and were given topical ALA under occlusive dressing for 3 hours followed by irradiation with semiconductor laser at a dose of 100 Jcm 2 and a power of 100 roW. The treatment was repeated 7 days later if the lesion was not completely removed after the first treatment. Complete response rate and recurrence rate of wart lesions as well as rate of adverse reaction were analyzed. Results The total complete response rate of PDT was 100% and the total recurrence rate was 5% after 3 months of follow-up. Recurrence rate of recurrent group was significantly lower than that of prior managements （100%, P〈0.01）. The side effects of PDT in patients mainly included mild burning and/or stinging restricted to the illuminated areas, and was significant lower than their own control （25% vs. 100%, P〈0.05）. Conclusion Compared with conventional therapies, topical application of ALA-PDT is a simple, effective, safe, well-tolerated, and low recurrence rate treatment for cervical condylomata acuminata.
文摘In order to investigate the correlation between the expression of the apoptotic regulatory proteins (Fas, Bcl 2) in peripheral blood lymphocytes (PBLC) and the level of IFN γ and IL 4 in serum of the patients with condyloma acuminata (CA) in the immune pathogenesis of CA, indirect immunofluorescence labeling method of flow cytometer and solid sandwich ELISA method were performed for detecting the expression of Fas, Bcl 2 in PBLC and the level of IFN γ and IL 4 in serum of 60 cases of CA. The results showed the expression level of Fas in PBLC of CA was significantly higher than in the normal control group, but the expression level of Bcl 2 was significantly lower (both P< 0.01). The level of IFN γ in serum of CA was significantly lower than in the normal control group ( P< 0.01), but IL 4 was significantly lower (both P< 0.01). The expression of Fas in PBLC had a negative correlation with the level of IFN γ in serum of patients with CA, but had a positive correlation with the level of IL 4; The expression of Bcl 2 had a positive correlation with the level of IFN γ, but had a negative correlation with the level of IL 4. All the correlation coefficients had significant differerce by t test ( P< 0.01). It was suggested abnormal apoptosis in PBLC, the suppressed secretion of the THl associated cytokines (eg: IFN γ) and the increased secretion of the TH2 asssociated cytokines (eg: IL 4) existed in the patients with CA and might play an important role in the immune pathogenesis of CA.
基金the Excellent Young Teacher’s Innovation Foundation of Northeast Forestry University to Yang FengJian,the Key Research Fund of Ministry of Educa-tion of China (Grant No.104191) the Forestry Noxious Plant Investigation Fund of State Forestry Administration of China to Zu YuanGang
文摘The traditional culture-dependent plate counting and culture-independent small-subunit-ribosomal RNA gene-targeted molecular techniques, Single-Strand Conformation Polymorphism (SSCP) and ter-minal Restriction Fragment Length Polymorphism (tRFLP) combined with 16S rDNA clone library were adopted to investigate the impacts of secretion from Camptotheca acuminata (abbreviated to Ca) roots on the quantities and structure of eukaryotic microbes and bacteria in the rhizosphere, and the possi-bility that Ca controls exotic invasive plant Eupatorium adenophorum (Ea). The counting results indi-cated that the number of bacteria increased in turn in rhizospheres of Ea, Ca-Ea mixed culture and Ca, while that of eukaryotic microbes decreased. PCR-SSCP profiles showed eukaryotic microbial bands (corresponding to biodiversity) in rhizosphere of Ea were more complex than those of Ca and CE. Meristolohmannia sp., Termitomyces sp. and Rhodophyllus sp. were the dominant populations in the rhizosphere of Ca. Bacterial terminal restriction fragments (TRFs) profiles showed no difference among three kinds of rhizospheres, and the sequences of the 16S rDNA clone library from Ca rhizospheres were distributed in 10 known phyla, in which phylum Proteobacteria were the absolute dominant group and accounted for 24.71% of the cloned sequences (δ-Proteobacteria accounted for up to 17.65%), and phyla Acidobacteria and Bacteroidetes accounted for 16.47% and 10.59% of the cloned sequences, respectively. In addition, high performance liquid chromatography detected a trace amount of camp-tothecin and hydroxycamptothecin in the rhizospheric soil of Ca and CE, but examined neither camp-tothecin nor hydroxycamptothecin in rhizospheric soil of Ea. Therefore, invasion and diffusion of Ea evidently depended on distinguishing the eukaryotic community structure, but not on that of the bac-terial pattern. Ca was able to alter the eukaryotic community structure of invasive Ea by secreting camptothecin and hydroxycamptothecin into rhizospheres, and may bene
基金supported by the National Key R&D Program of China(No.2019YFC1711100)the CAMS Innovation Fund for Medical Sciences(CIFMS,No.2016-I2M-3-016)。
文摘Camptotheca acuminata produces camptothecin(CPT),a monoterpene indole alkaloid(MIA)that is widely used in the treatment of lung,colorectal,cervical,and ovarian cancers.Its biosynthesis pathway has attracted significant attention,but the regulation of CPT biosynthesis by the APETALA2/ethylene-responsive factor(AP2/ERF)transcription factors(TFs)remains unclear.In this study,a systematic analysis of the AP2/ERF TFs family in C.acuminata was performed,including phylogeny,gene structure,conserved motifs,and gene expression profiles in different tissues and organs(immature bark,cotyledons,young flower,immature fruit,mature fruit,mature leaf,roots,upper stem,and lower stem)of C.acuminata.A total of 198 AP2/ERF genes were identified and divided into five relatively conserved subfamilies,including AP2(26 genes),DREB(61 genes),ERF(92 genes),RAV(18 genes),and Soloist(one gene).The combination of gene expression patterns in different C.acuminata tissues and organs,the phylogenetic tree,the co-expression analysis with biosynthetic genes,and the analysis of promoter sequences of key enzymes genes involved in CPT biosynthesis pathways revealed that eight AP2/ERF TFs in C.acuminata might be involved in CPT synthesis regulation,which exhibit relatively high expression levels in the upper stem or immature bark.Among these,four genes(Cac AP2/ERF123,Cac AP2/ERF125,Cac AP2/ERF126,and Cac AP2/ERF127)belong to the ERF–B2 subgroup;two genes(Cac AP2/ERF149 and Cac AP2/ERF152)belong to the ERF–B3 subgroup;and two more genes(Cac AP2/ERF095 and Cac AP2/ERF096)belong to the DREB–A6 subgroup.These results provide a foundation for future functional characterization of the AP2/ERF genes to enhance the biosynthesis of CPT compounds of C.acuminata.
文摘Plants interact with their environment by producing a diverse array of secondary metabolites, one of which is alkaloid. In this study, alkaloids, including camptothecin (CPT) and 10-hydroxycamptothecin (HCPT), malondialdehyde (MDA) and chlorophyll contents were measured during heat shock in seedlings of Camptotheca acuminata Decaisne unique to China. Responses of different tissues, including young leaves, old leaves, buds and barks, to heat shock were examined in alkaloid changes. CPT and HCPT concentrations reached their peak values separately at 38 degreesC and 40 degreesC, which were below the lethal heat-shock temperature indicated by MDA and chlorophyll, and their great changes took place in young leaves. These results indicated that CPT and HCPT were involved in the C acuminata resistance against heat shock from its environment. Furthermore, plant rigidly observed the cost-benefit principle and mobilized and allocated limited alkaloid sources to young and reproductive tissues preferentially. In addition, HCPT displayed well-regulated changes during incubation at sublethal temperature, and this indicated that HCPT might play a more positively defensive role in enhancement of plant thermotolerance than CPT does.
基金教育部重点项目，Application Fund of Agricultural Research Production
文摘Axillary buds from 3-yr.-old seedlings of Camptotheca acuminata in the greenhouse were cultured on the different basal media with different concentrations of growth regulators for shoot regeneration for studying the effects of different basal media, different concen- trations of growth regulators (BA or TDZ), sucrose, agar and pH value on shoot regeneration from axillary bud. The results showed that B5 and WPM media were the optimal basal media and the optimal phyotohormone was BA of 1.0 mg/L or TDZ of 0.1mg/L; The concentrations of sucrose of 30g/L and agar of 6g/L were most suitable for the shoot regeneration; pH value from 5.8 to 6.6 were broadly effective, but the best at pH 5.8.
基金This paper was supported by the Heilongjiang Province Foundation for Distinguished Youth Scholars (JC-02-11)
文摘Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi （AMF）, Acaulospora mellea, Glomus diaphanum and Sclerocystis sinuosa.. The height, biomass, and absorptions of nitrogen and phosphorus of C. acuminata seedlings inoculated with AMF were investigated. The results showed that the formation of AM promoted the height growth and biomass accumulation of seedlings significantly and improved the absorption of phosphorus in seedlings. The height and biomass of mycorrhizal seedlings were 1.2 and 1.6 times higher than those of the non-mycorrhizal seedlings. The absorption of nitrogen was less influenced by the formation of AM. The nitrogen content in mycorrhizal seedling was equal to that of non-mycorrhizal seedlings. Compared with non-mycorrhizal seedlings, the nitrogen content of mycorrhizal seedlings inoculated with A. mellea changed considerably in the root, stem and leaves. The difference in nitrogen content was not significant between mycorrhizal seedlings inoculated with G. diaphanum and S. sinuosa. The AM formation stimulated the absorption of phosphorus, especially in roots, and also changed the allocation of nitrogen and phosphorus in different organs of seedlings. Compared with non-mycorrhizal seedlings, the ratio of nitrogen and phosphorus in mycorrhizal roots increased, but reduced in stem and leaves.
基金Project (No. 30471112) supported by the National Natural Science Foundation of China
文摘Objective： Chilling tolerance of salicylic acid （SA） in banana seedlings （Musa acuminata cv., Williams 8818） was investigated by changes in ultrastructure in this study. Methods： Light and electron microscope observation. Results： Pretreatment with 0.5 mmol/L SA under normal growth conditions （30/22 ℃） by foliar spray and root irrigation resulted in many changes in ultrastructure of banana cells, such as cells separation from palisade parenchymas, the appearance of crevices in cell walls, the swelling of grana and stromal thylakoids, and a reduction in the number of starch granules. These results implied that SA treatment at 30/22 ℃ could be a type of stress. During 3 d of exposure to 7 ℃ chilling stress under low light, however, cell ultrastructure of SA-pretreated banana seedlings showed less deterioration than those of control seedlings （distilled water-pretreated）. Conclusion： SA could provide some protection for cell structure of chilling-stressed banana seedling.
基金This paper was supported by National Natural Science Foundation of China (No. 30070086).
文摘The determination method of 10-hydroxycamptothecin in Camptotheca acuminata fruits by high-performance liquid chromatogram (HPLC) was studied. The HPLC analysis was performed on a HIQ sil C18(4.6×250 mm) column with mobile phase of acetonitrilewater (3:7, V:V), flow rate 1 mLmin-1 and UV detective wavelength 266 nm. Extracting 10-hydroxycamptothecin by ultrasonic method from fruits of C. acuminata to prepare samples for analysis was systematically discussed. The optimal extraction condition was carried out by 60% alcohol solution at 60℃ for 50 minutes.
