首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 8 毫秒
1.
Production of the ipecac alkaloids, emetine and cephaeline was studied in cell suspension and excised root cultures of Cephaelis ipecacuanha. A two-stage cell suspension culture was developed for enhanced accumulation of the alkaloids. In the first-stage, suspension cultures were established in Murashige and Skoog's (MS) medium containing 2,4-D and NAA which was suitable for cell growth and the second-stage culture system was composed of MS medium containing IBA, IAA and 6% sucrose which favoured alkaloid production. The production of emetine and cephaeline was greatly increased in the two-stage culture method compared to the single-stage culture. Optimal alkaloid synthesis was obtained in excised root culture of the plant in medium composed of half-strength MS salts, IBA (0.25 mgl−1) and 2% sucrose. A discernible higher accumulation of cephaeline in two-stage cell suspension culture as well as in excised root culture in comparison to that of the three-year-old roots was a  相似文献   

2.
吐根作为治疗痢疾的特效药而著名,主要具有祛痰、催吐和抗阿米巴痢疾的作用。我国目前对吐根药材的需求全部依赖于进口,国内未有大规模种植,为此,该文对原产巴西的吐根进行了引种繁殖及栽培研究。结果表明:(1)云南省西双版纳傣族自治州景洪市的气候条件能满足吐根的正常生长发育的需求,可作为吐根的引种地。(2)吐根的分根和茎下段可用于扦插繁殖,其发根率和存活率分别100.0%和100.0%、68.0%和75.0%,前者优于后者。(3)用20 mg·L-1的IAA或IBA浸泡1 h,吐根茎下段的扦插成活率为90.0%或88.0%,均显著高于对照,可用于提高吐根茎下段的扦插成活率。(4)采用分根繁殖的吐根植株在植株生长和药材外观性状较好,单株总根体积较高,吐根一年生植株平均株高为10.66 cm,两年生平均株高为16.54 cm,一年生植株根总体积为2.71 mL,两年生根总体积为3.54 mL。(5)吐根栽培基质可用腐殖土:椰糠体积比为4:1。(6)在吐根的年周期生长中,地径1—3月和9—11月增长明显,株高7—11月增长明显,叶片长和宽3—9月增长明显,根据这些特点,可科学制定相应的水肥管理措施。该研究结果可为吐根的引种繁殖和栽培提供一定的科学参考。  相似文献   

3.
Euterpe edulis flowers at the beginning of the wet season and fruits over an extended period during the end of the wet season and the dry season. Reproductive plants produced an average of ca 1500 fruits within a season. Five species of birds belonging to the family Turdidae were observed to feed on and disperse the fruits. Most seeds fell directly to the ground, where there was some subsequent local dispersal by water. The dispersion of seeds was highly clumped with most seeds being found in close proximity to adult plants; the distance of dispersal could be described by a negative power curve. Germination was higher on wetter soils. The probability of seedlings advancing to the next size class within a year was inversely related to the density of seedlings, and occurred optimally at ca 4 m from adult plants. The latter observation indicates that the survival and growth of seedlings are suppressed in the immediate vicinity of conspecific adults.  相似文献   

4.
Three cyanidin glycosides have been identified in the black carrot: the known 3-lathyroside and two new pigments, a 3-xylosylglucosylgalactoside and its ferulyl derivative. The same pigments, together with the sinapyl derivative of the triglycoside, occur variously in other tissues of Daucus carota. Ferulyl and sinapyl derivatives of cyanidin 3-glucosylgalactoside occur exceptionally in stem of one subspecies, maritimus. One or other of the same pigments have been found to occur variously in 20 of 22 other umbellifer species surveyed. Both ferulyl and sinapyl derivatives occur in stem of Conium maculatum and Foeniculum vulgare. A further novel acylated pigment based on p-coumaric acid was found in wild celery, Apiurn graveolens. The systematic significance of these various findings is discussed.  相似文献   

5.
Twelve anthocyanins have been isolated from flax: the 3-glucosylrutinosides of pelargonidin, cyanidin and delphinidin; the 3-triglucosides of delphinid  相似文献   

6.
为探究三七绿紫过渡地上茎的花色苷和皂苷组织定位与含量的相关性,采用显微组织化学法研究云南文山三七的一年生植株绿紫过渡地上茎各茎段花色苷和皂苷的组织定位,用分光光度法检测茎段的总花色苷(TAC)和总皂苷含量(TSC),用高效液相色谱检测了茎段的皂苷单体含量。结果表明:(1)在三七绿紫过渡地上茎的中部横截面上,花色苷主要定位在皮层薄壁组织外侧的2层或2~3层细胞中,而皂苷主要定位在维管束中;各茎段的皂苷单体均主要为人参皂苷Rb1。(2)从茎顶向茎基,茎段中TAC、TSC和Rb1的含量总体上分别表现为一条"单峰"、"V形"和"降-升-降三段式"曲线;其中,花色苷主要积累在茎的中、上部,总皂苷在茎的下、基部,Rb1则在茎的上半段,而且TAC最高以及TSC和Rb1含量最低的茎段均恰好定位在中上部的黄金分割点处。(3)不同茎段间的TAC含量差异显著,Rb1含量差异极显著,但TSC含量的差异不显著;不同茎段间的TAC与TSC、Rb1含量呈不同的相关性,整个地上茎的TAC与TSC含量间呈极显著负相关关系、TAC与Rb1含量间呈不显著正相关。研究认为,在三七绿紫过渡地上茎中,花色苷和皂苷的横向组织定位不同,二者含量在纵向上总体呈负相关。  相似文献   

7.
该研究以黑粒青稞品种‘黑老鸦’籽粒为材料,克隆了青稞类黄酮3-O-葡萄糖基转移酶基因(HvtUF3GT),获得1 449 bp序列。HvtUF3GT基因包含一个1 434 bp开放阅读框,编码478个氨基酸,理论等电点为5.45,预测蛋白分子量为52 912.58 Da。蛋白质序列分析表明,HvtUF3GT为亲水性的不稳定酸性蛋白,且在C-末端具有一段典型的44个氨基酸PSPG box,在空间结构中含有β-α-β-α-βRossmann折叠结构,属于UDP糖基转移酶基因GT-B型超家族成员。进化树分析表明,HvtUF3GT与小麦族的大麦、乌拉尔图小麦、山羊草和二穗短柄草的糖基转移酶聚为一个分支,且与大麦的亲缘关系最近,与稻族的籼稻和短花稻的亲缘关系较远。半定量和定量PCR结果表明,在‘INB0N-7’蓝粒青稞和‘昆仑12号’白粒青稞的籽粒灌浆后期HvtUF3GT基因不表达,而在黑粒青稞和紫粒青稞中的表达强弱依次为‘黑老鸦’(黑粒)‘昆仑17号’(黑粒)‘达章紫’(紫粒)‘涅如姆扎’(紫粒)。研究推测,HvtUF3GT基因在青稞灌浆后期籽粒着色过程中发挥着重要作用。  相似文献   

8.
Effects of soil flooding on photosynthesis and growth of Genipa americana L. seedlings, a neotropical fruit-tree species used in gallery forest restoration programs, were studied under glasshouse conditions. Despite the high survival rate and wide distribution in flood-prone habitats of the neotropics, previous studies demonstrated that growth of G. americana is reduced under soil flooding. Using leaf gas exchange and chlorophyll fluorescence measurements, we tested the hypothesis that stomatal limitation of photosynthesis is the main factor that reduces carbon uptake and growth rates of G. americana seedlings. Throughout a 63-day flooding period, the survival rates were 100%. The maximum values of the net photosynthetic rate (A) and stomatal conductance to water vapor (gs) of control seedlings were 9.86 μmol CO2 m−2 s−1 and 0.525 mol H2O m−2 s−1, respectively. The earliest effects of flooding were significant decreases in gs and A, development of hypertrophied lenticels and decrease in the dry weight of roots. A strong effect of the leaf-to-air vapor pressure deficit (LAVPD) on gs and A were observed that was enhanced under flooded conditions. Between 14 and 63 days after flooding, significant reductions in gs (31.7% of control) and A (52.9% of control) were observed followed by significant increments in non-photochemical quenching (qN) (187.5% of control). During the same period, there were no differences among treatments for the ratio between variable to initial fluorescence (Fv/F0), the maximum quantum efficiency of the photosystem II (Fv/Fm) and photochemical quenching (qP), indicating that there was no damage to the photosynthetic apparatus. Based on the results, we conclude that decreases in stomatal opening and stomatal limitation of photosynthesis, followed by decrease in individual leaf area are the main causes of reductions in carbon uptake and whole plant biomass of flooded seedlings.  相似文献   

9.
The algicidal effects of crude and pure rice hull extracts on the growth of Microcystis aeruginosa were investigated using cultured unicellular and colonial strains. Upon treatment with rice hull crude extract (RHE), growth inhibition of unicellular M. aeruginosa was much higher than that of colonial M. aeruginosa. However, purified compounds from the crude extract, β-sitosterol-β-d-glucoside and dicyclohexanyl orizane, powerfully inhibited the growth of colonial M. aeruginosa cells. At the same concentrations, the two compounds were almost equipotent (66% and 80% growth inhibition for colonial M. aeruginosa, respectively; P < 0.05). As rice hulls are readily obtainable, and as extracts show high algicidal activity (targeting colonial algae rather than unicellular organisms) at low concentrations, the results suggest that some pure compounds extracted from rice hulls, such as β-sitosterol-β-d-glucoside and dicyclohexanyl orizane, may serve as environmentally friendly agents for controlling the growth of toxic colonial M. aeruginosa in eutrophic waters.  相似文献   

10.
为优化八仙花花色苷提取条件,探究具有不同花色可调性的八仙花花色苷组分和理化稳定性差异,初步解释八仙花花色可调性存在差异的原因,该文以花色不可调的‘蒂亚娜(Tijana)’和花色可调的‘拉维布兰(Ravi Brent)’八仙花(Hydrangea macrophylla)为材料,通过L9(33)正交试验确定超声波法提取花色苷的最优条件,利用UPLC-Q-TOF-MS法进行花色苷组分的鉴定,分析离体条件下温度、光照、金属离子和糖类对八仙花花色苷理化稳定性的影响。结果表明:(1)花色苷提取的最优条件是‘蒂亚娜’和‘拉维布兰’的乙醇浓度分别为70%和80%,料液比均为1∶20,提取时间均为20 min。(2)二者的主要花色苷组分均为飞燕草素-3-O-葡萄糖苷。(3)八仙花花色苷在温度≤70℃暗处保存效果更好。(4)花色不可调的‘蒂亚娜’八仙花花色苷对光照、糖类和大多金属离子更稳定;只有花色可调的‘拉维布兰’八仙花花色苷加入中低浓度(10~30 mmol·L-1)Al3+后由粉色变为蓝色且稳定性提高,而‘蒂亚...  相似文献   

11.
孙爽  胡颖  陆晶宇  杨章旗  陈虎 《广西植物》2022,42(4):580-595
MYB类转录因子在植物生长发育、代谢、应答生物胁迫和非生物胁迫的响应等生物过程发挥重要作用。为探究马尾松R2R3-MYB基因结构及功能,该研究以转录组数据为研究区域,从中筛选获得了17个马尾松R2R3-MYB基因,利用生物信息学对基因进行理化性质、系统进化树等分析,同时利用荧光定量PCR技术分析基因的组织特异性以及在花发育时期和非生物胁迫下的表达模式。结果表明:(1)17个PmMYBs亚细胞定位于细胞核,均无跨膜结构,且均含有Motif1、Motif2保守基序。系统发育进化树将马尾松PmMYBs划分为9个亚家族,且与火炬松、白云杉等裸子针叶植物关系较近。(2)17个基因均属于组成型表达,但在不同组织的表达量不同;所有基因均参与了花发育和非生物胁迫,不同基因在花发育不同时期的表达存在差异,有7个基因可能参与了雌雄性状转变;大部分基因响应非生物胁迫上调表达,但响应胁迫的时间存在差异;少数基因在胁迫中下调表达,尤其是PmMYB11基因在所有胁迫中均明显下调表达。该研究较系统地分析了马尾松R2R3-MYB基因的结构特征、系统进化及其在花发育时期和非生物胁迫下的表达模式,为深入探究马尾松R2R3...  相似文献   

12.
Of 80 fluorescent pseudomonad strains screened for phosphate solubilization, three strains (BFPB9, FP12 and FP13) showed the ability to solubilize tri-calcium phosphate (Ca3(PO4)2). During mineral phosphate solubilization, decrease of pH in the culture medium due to the production of organic acids by the strains was observed. These phosphate solubilizing strains produced indole-3-acetic acid (IAA) and protease as well as exhibited a broad-spectrum antifungal activity against phytopathogenic fungi. When tested in PCR using the gene-specific primers, strain BFPB9 showed the presence of hcnBC genes that encode hydrogen cyanide. On the basis of phenotypic traits, 16S rRNA sequence homology and subsequent phylogenetic analysis, strains BFPB9, FP12 and FP13 were designated as Pseudomonas aeruginosa, P. plecoglossicida and P. mosselii, respectively. Present investigation reports the phosphate solubilization potential and biocontrol ability of new strains that belong to P. plecoglossicida and P. mosselii. Because of the innate potential of phosphate solubilization, production of siderophore, IAA, protease, cellulase and HCN strains reported in this study can be used as biofertilizers as well as biocontrol agents.  相似文献   

13.
14.
The gene cluster (ery) governing the biosynthesis of the macrolide antibiotic erythromycin A by Saccharopolyspora erythraea contains, in addition to the eryA genes encoding the polyketide synthase, two regions containing genes for later steps in the pathway. The region 5′ of eryA that lies between the known genes ermE (encoding the erythromycin resistance methyltransferase) and eryBIII (encoding a putative S-adenosylmethionine-dependent methyltransferase), and that contains the gene eryBI (orf2), has now been sequenced. The inferred product of the eryBI gene shows striking sequence similarity to authentic β-glucosidases. Specific mutants were created in eryBI, and the resulting strains were found to synthesise erythromycin A, showing that this gene, despite its position in the biosynthetic gene cluster, is not essential for erythromycin biosynthesis. A␣mutant in eryBIII and a double mutant in eryBI and eryBIII were obtained and the analysis of novel erythromycins produced by these strains confirmed the proposed function of EryBIII as a C-methyltransferase. Also, a chromosomal mutant was constructed for the previously sequenced ORF19 and shown to accumulate erythronolide B, as expected for an eryB mutant and consistent with its proposed role as an epimerase in dTDP-mycarose biosynthesis. Received: 13 August 1997 / Accepted: 27 November 1997  相似文献   

15.
The internal flavonoid patterns of Pityrogramma triangularis fronds were found to distinguish diploids and tetraploids of two exudate chemotypes (the ceroptin and the kaempferol methyl ether types). The flavonoid data suggest that the tetraploid-kaempferol methyl ether chemotype is of alloploid origin involving the two diploid chemotypes because the flavonoid pattern for the former represents a pattern additive of the two diploids, while the tetraploid-ceroptin chemotype may be of autoploid origin, as deduced from the similarity of the diploids and tetraploids.  相似文献   

16.
Ankyrins are a family of adapter molecules mediating linkages between integral membrane and cytoskeletal proteins. Ankyrin repeat is one of the most frequently observed amino acid motifs in protein databases. A novel ANK-like gene of Chinese mitten crab Eriocheir japonica sinensis (denoted as EjsANK) was identified and cloned by expressed sequence tag and rapid amplification of cDNA end approaches. The full-length cDNA of EjsANK is 4375 bp and contains an open reading frame of 1095 bp which encodes a 364 amino acids polypeptide (40.23 kD) bearing seven ankyrin repeats. EjsANK cDNA has a 3073 bp uniquely long 3′ untranslated region with three K-box elements, one GY-like box domain and one Brd-like box domain. Sequence alignment and three-dimensional structural analyses revealed that EjsANK should be a novel cytosolic member of the ankyrin family. Fluorescent real-time quantitative RT-PCR approach was performed to examine the expression profiles of EjsANK mRNA by testing its relative level in three types of tissues at three different developmental stages, respectively. We found that the relative level of EjsANK mRNA expression was significantly higher in the abdomen at the first crab stage. Functional bioinformatics prediction analyses indicated that EjsANK has an analogical effect like IκB which is a key component of IκB/NF-κB complex in mammalian cells playing very important roles in the development process. Results suggest that EjsANK gene is involved in the early developmental regulation of Chinese mitten crab, especially brachyurization regulation.  相似文献   

17.
A new cyanogenic glucoside, isolated from pods of Acacia sieberiana var. woodii, was shown to be (2R)-2- (β-d-glucopyranosyloxy)-3-hydroxy-3-methylbutanenitrile by spectroscopic and chemical methods. The absolute configuration of this glucoside was correlated with that of proacacipetalin by oxymercuration of the latter, followed by borohydride reduction of the product.  相似文献   

18.
The purpose of the present study is to investigate the effect of methanolic extracts of Aegles marmelos and Syzygium cumini on a battery of targets glucose transporter (Glut-4), peroxisome proliferator activator receptor gamma (PPARgamma) and phosphatidylinositol 3' kinase (PI3 kinase) involved in glucose transport. A. marmelos and S. cumini are anti-diabetic medicinal plants being used in Indian traditional medicine. Different solvent extracts extracted sequentially were analysed for glucose uptake activity at each step and methanol extracts were found to be significantly active at 100ng/ml dose comparable with insulin and rosiglitazone. Elevation of Glut-4, PPARgamma and PI3 kinase by A. marmelos and S. cumini in association with glucose transport supported the up-regulation of glucose uptake. The inhibitory effect of cycloheximide on A. marmelos- and S. cumini-mediated glucose uptake suggested that new protein synthesis is required for the elevated glucose transport. Current observation concludes that methanolic extracts of A. marmelos and S. cumini activate glucose transport in a PI3 kinase-dependent fashion.  相似文献   

19.
β-chitin and its chitosan from the pens of Loligo lessoniana and Loligo formosana has been isolated, prepared, and physico-chemically characterized to demonstrate a potential chitin source. Without deminerization due to negligible ash content, only deproteinization was used in the chitin isolation with an yield of 35–38%, without significant difference either between the two species or the collection seasons. Reducing step not only saves production cost but also obviates acid pollutant. Mild alkaline deacetylation with various time periods was employed in the chitosan preparation. Optical rotation and thermal transition of chitin from both species suggested the weak intermolecular forces compared with shrimp chitin. The results of nitrogen contents indicate the effectiveness of the deproteinization method used. The samples were categorized as a Class III: moderate hygroscopicity. Traces of elements presented in pens markedly decreases but are incapable to be got rid of within the step of chitin–chitosan preparation. In addition, a small amount of cadmium, as the contamination, was detected in the samples from L. formosana.  相似文献   

20.
枫香(Liquidambar formosana)因其叶片入秋后逐渐变红而极具观赏价值,是优良的景观生态树种。为了解枫香叶片结构变化与叶色的关系,该文通过连续监测枫香叶片变红过程中组织结构、光合特性及色素含量的变化,分析叶片结构与其光合特性和色素的关系。结果表明:(1)叶片变色过程中,表皮细胞均为椭圆形,紧密排列,未观察到明显的细胞变异,表面未附着绒毛和蜡质,且上表皮细胞与栅栏组织细胞间排列紧密,未出现较大的气室。(2)随着叶片逐渐变红,叶片结构变化显著,其中叶片、上表皮、栅栏组织和海绵组织厚度及气孔开度均逐渐减小,而气孔器长和宽、单个气孔器面积则逐渐增大。(3)随着叶片结构的变化,其叶绿素含量逐渐减少,致使净光合速率逐渐减小,在出现光破坏时,叶片通过在栅栏组织细胞液泡内合成花色苷来自我保护,而大量的花色苷致使叶片表面呈现红色。综上认为,叶绿素含量降低,花色素苷大量积累是导致枫香叶片变红的直接原因,而枫香叶色变红则是其一系列生理结构特征综合作用的结果。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号