The Construction of Fusion Expression Vector Carrying GFP and TP of GGPPS from Ginkgo biloba L.

[Objective]The aim was to construct the fusion gene expression vector which consisted of GFP and TP gene of GGPPS from the Ginkgo biloba L.[Method]The transit-peptide（TP） sequence of GGPPS from cDNA of Ginkgo biloba L.was successfully cloned by using DNA recombination technology,which was then linked to the efficient plant expression vector p1304 ＋ to construct the fusion gene expression vector p1304 ＋-TP.Then engineering strain EHA105-p1304 ＋-TP was constructed by transformed p1304 ＋-TP to Agrobacterium rhizogenes EHA105 using freeze-thaw method.[Result]The fusion gene expression vector which consisted of GFP and TP gene of GGPPS from the Ginkgo biloba L.and engineering strain EHA105-p1304 ＋-TP were successfully constructed.[Conclusion]It lays a foundation for further study of subcellular localization of TP transit peptide,which can help to clarify the molecular mechanism of a key step in biosynthesis of ginkgolides precursors,and also provides an important basis for the research on metabolic engineering of ginkgolide.

Cloning and Functional Analysis of HDR Gene from Ginkgo biloba L

[Objective] The aims were to obtain cloning of HDR gene from Ginkgo biloba.and study its function.[Method] The coding sequence of HDR gene was cloned from G.biloba by reversed transcription polymerase chain reaction,which was designated as GbHDR （GenBank accession No.：DQ364231）.The cDNA full-length of GbHDR is 1 827 bp containing a 1 425-bp open reading frame （ORF） encoding a 474-amino-acid polypeptide and constructed into the prokaryotic expression vector pTrcGbHDR.The β-carotene biosynthetic pathway in E.coli strain XL1-Blue was reconstructed by transforming with pAC-BETA.This engineered XL1-Blue was transformed with pTrcGbHDR.[Result] A 1 441 bp GbHDR was obtained containing a 1 425-bp ORF encoding a 474-amino-acid residues of protein,the predicted molecular weight was 53.2 kD,and predicted isoelectric point was 5.76.Functional complementation assay indicated that GbHDR could promote theβ-carotene accumulation in engineered XL1-Blue harboring pTrcGbHDR and pAC-BETA,and as a result,the engineered bacteria showed the brightly orange given by β-carotene.This suggested that GbHDR had the typical function of known HDR genes.[Conclusion] A engineered bacteria of E.coli which could highly accumulate β-carotene was obtained,which will provide candidate genes and targets for realizing β-carotene metabolic engineering.

Preliminary Study on Water Physiological Characters of Male and Female Ginkgo biloba L.

[Objective] The experiment aimed to study the difference of water physiology of male and female Ginkgo biloba L. for discussing the strategy of water utilization as well as the important role of this difference during evolution process. [Method] The stem sap flow, stomatal conductance(Gs), transpiration rate(Tr) and water use efficiency (WUE) of male and female Ginkgo biloba L. were comparatively studied. [Result] The day-night processes of flow on male and female Ginkgo biloba L. were similar. The flow on male and female Ginkgo biloba L. in day were almost same while the flow at night on male Ginkgo biloba L. was bigger than that on female Ginkgo biloba L. The Tr and Gs of male and female Ginkgo biloba L. were high in morning and at night but low at noon ,while Tr and Gs of female Ginkgo biloba L. in morning and at night were higher than these of male Ginkgo biloba L. at the same time point. However, these indexes of female plant were lower than these of male plant from 11:00 to 14:00. WUE changing trends of male and female Ginkgo biloba L. were similar, while average water utilization rate of female Ginkgo biloba L. was slightly lower than that of male Ginkgo biloba L. [Conclusion] Compared with other companion plants, water physiology of male and female Ginkgo biloba L. had strong homoplasy. The phenomenon might be a survival strategy of dioecious plants under long term evolutionary pressure.

孑遗植物银杏(Ginkgo biloba L.)雌雄株水分生理特征初步研究

[目的]研究银杏雌雄株在水分生理上的差异，探讨其水分利用策略，以及在进化过程中的重要作用。[方法]对银杏雌雄株的树干液流（sap flow）、气孔导度（Gs）、蒸腾速率（Tr）以及水分利用效率（WUE）进行对比研究。[结果]雌雄银杏的液流昼夜进程具有相似的规律，且白天雌雄株液流基本相同，夜间雄株液流大于雌株；不同性别银杏的丹和岱同样呈现为早晚高、午间低的曲线趋势，早晚雌株有比雄株更高的Tr和Gs，但中午11：00-14：00之间雌株的值低于雄株；雌雄银杏的WUE曲线变化趋势相似，但雌株的平均水分利用效率略小于雄株。[结论]与其他伴性植物比较分析得知，不同性别银杏的水分生理有较强的趋同特征。这可能是在长期进化的压力下，雌雄异株植物的一种生存策略。

Dynamic changes of telomeric restriction fragment (TRF) lengths in cells during the developmental process from embryos to seedlings and a comparison with the embryonal calli in Ginkgo biloba L.

Telomeres are the structures that locate at the terminals of linear eukaryotic chromosomes. They can play essential roles in many cellular processes. The terminal location ofArabidopsis-type TTTAGGG tandem repeats were thought to be highly conserved. The terminal location of Ginkgo biloba L. consisting of TTTAGGG tandem repeats, were confirmed by Bal31 exonuclease degradation and Southern blotting. By comparing telomeric restriction fragment （TRF） lengths at different developmental stages from embryos to seedlings, a fluctuant tendency towards variation was found in these samples. The TRF length of embryos was also compared with that of embryonal calli and an upward trend was discovered in callus culture. The results suggest that there should be a telomerase mechanism or/and ALT mechanism for the maintenance of telomere length.

Cloning and Analysis of Telomere-associated Sequences of Ginkgo biloba L..

Total genomic DNA was extracted from leaves of Ginkgo biloba L. by the method of hot CTAB. After determining quantification of DNA sample by microclorimetric spectrophotography, Arabidopsis-type telomere primer and Sau3AⅠ cassette primer were used to isolate telomere-associated sequences from G. biloba L. by the method of cassette-ligation-mediated polymerase chain reaction (PCR). Using this method, two telomere-associated sequences, TAS1 and TAS2, were isolated. The authors preformed Southern hybridization of EcoRⅠ-treated G. biloba genomic DNA with each clone. The hybridization pattern showed that the clones obtained were derived from G. biloba genomic DNA. There are the Arabidopsis-type TTTAGGG tandem repeats in telomeres of G. biloba.

Mechanism of Ginkgo biloba L.leaf in the treatment of ischemic stroke based on network pharmacology,bioinformatics and molecular docking

Ginkgo biloba L.leaf(GBL)has been reported to protect against ischemic stroke(IS),one of the leading causes of death and longterm disability worldwide,while there is a lack of systematic study on the exact mechanism.Here,network pharmacology and bioinformatics were used to predict the active components,important targets,and potential mechanisms of GBL in the treatment of IS.Active compounds of GBL were screened based on drug-like index and oral bioavailability,key target genes were screened based on network pharmacology and gene chip,downstream pathways for the regulation of key target genes were predicted based on gene set enrichment analysis,and the interaction between key targets and active compounds was verified based on molecular docking.The results showed that GBL played a protective role in cerebral ischemia with mainly 14 active compounds,such as isoquercitrin,luteolin-4’-glucoside,beta-sitosterol,campesterol,diosmetin,ginkgolide B,ginkgolide C,ginkgolide J,ginkgolide M,isogoycyrol,laricitrin,luteolin,sesamin,and stigmasterol.Further studies revealed that GBL played important role in immunomodulation and inflammation inhibition after cerebral ischemia by acting on its peripheral targets ARG1 and MMP9 to regulate Toll-like receptor,Chemokine and Notch signaling pathway.Meanwhile,GBL played important role in reducing neuroinflammation and blood-brain barrier damage after cerebral ischemia by acting on its central targets,CCL2,PTGS2,IL6,IL1B and MMP9 to regulate the Cytokine-cytokine receptor interaction,Jak-STAT,and Toll-like receptor signaling pathway.Additionally,molecular docking verified that the active compounds mentioned above could bind to ARG1,MMP9,CCL2,PTGS2,IL6,and IL1B.The present study shows the multicomponent,multitarget and multichannel pharmacological effects of GBL on cerebral ischemia and provides a new strategy for the treatment of IS.

Extraction Process and Content Determination of Total Flavonoids in Ginkgo( Ginkgo biloba L. ) Leaves

[Objectives]This study was conducted to study the extraction process and the content determination of flavonoids in ginkgo( Ginkgo biloba L.) leaves.[Methods]Ethanol extraction and methanol extraction of total flavonoids in ginkgo leaves were studied,and the optimal extraction conditions for flavonoids were determined by orthogonal test; and with quercetin as reference substance,total flavonoid content in ginkgo leaves was determined by UV spectrophotometry.[Results]The optimal extraction process was 4 h of Soxhlet extraction with methanol; and the total flavonoid contents had a good linear relation in the range of 0. 006 5-0. 039 mg/ml( R^2= 0. 999 9),the average content was stabilized at 1. 135%,and the average recovery of the method was 102. 0%. [Conclusions]This study selected the optimal extraction process for total flavonoids in ginkgo leaves. The test method is simple with high accuracy and precision,and is suitable for the extraction and determination of total flavonoids in ginkgo leaves.

Effects of Coupling Treatment of Acid and Aluminum under Soilless Culture on Water Content of Ginkgo biloba L.

In this experiment,two-factor 7-level uniform design scheme was applied.Separate treatment of each factor was performed for single effect test.Then,it analyzed the effects of acid and aluminum stress under soilless culture on the water content of plant during the growth of Ginkgo biloba L.seedlings,so as to provide a theoretical basis for studying the connection between plant water and physiological stress.The results showed that the water content of G.biloba plants declined with the decrease of p H,but the water content of G.biloba plants declined with the increase in the concentration of aluminum treatment,indicating that the stronger the acid and aluminum stress,the lower the water content of the plants,affecting the normal absorption of water content of G.biloba plants,accordingly leading to lack of water.According to the analysis of the degree of influence on the water content,p H is the first factor influencing the growth of G.biloba plants.If p H is lower than 3.5,G.biloba plants will not growth,while p H is higher than 5.0,aluminum has no significant effect on the water content of G.biloba plants.In conclusion,the water content of G.biloba plants can be used as an essential indicator for acid and aluminum stress.

Determination of the Content of Kaempferol from Fermented Ginkgo( Ginkgo biloba L.) Leaves

[Objectives] This study was conducted to determine kaempferol content in ginkgo( Ginkgo biloba L.) leaves subjected to microbial fermentation.[Methods]Bacillus licheniformis was selected for solid-state fermentation of ginkgo leaves,and the content of kaempferol in ginkgo leaves was determined by RPHPLC method. At first,methanol was used to extract flavonoid glycosides,which were then hydrolyzed by hydrochloric acid solution. HPLC was performed with Platisil ODS column C18( 150 mm ×4. 6 mm,5 μm) using mobile phase Vmethanol∶ Vwater( 0. 4% phosphoric acid solution) = 55∶45 at a flow rate of 1 ml/min,and the eluate was detected with a shimadzu HPLC ultraviolet detector at 360 nm. [Results]With kaempferol as the reference substance,the correlation coefficient was0. 999 2 in the range of 0. 001 06-0. 016 96 g/L. The content in the fermented product was less than that in the non-fermented product by 28%. [Conclusions]The method is simple,accurate,and is suitable for determination of kaempferol. This study will provide an experimental basis for the development and utilization of ginkgo.

Simultaneous quantification of flavonol glycosides, terpene lactones, polyphenols and carboxylic acids in Ginkgo biloba leaf extract by UPLC-QTOF-MS^E based metabolomic approach

Abstract： In the present study, we established an ultra performance liquid chromatography coupled with time-of-flight mass spectrometry （UPLC-QTOF-MSE） method to simultaneously quantify 33 components in Ginkgo biloba leaf extracts （GBEs）, including 17 flavonol glycosides, five terpene trilactones （TTLs）, four polyphenols and seven carboxylic acids. This optimized method was successfully applied to analyze the explicit compositions of GBE samples collected from different places. Furthermore, the data were processed through unsupervised principal component analysis （PCA） and supervised orthogonal partial least squared discrimination analysis （OPLS-DA） to evaluate the quality and compare the differences between the samples according to the contents of the 33 chemical constituents. Bilobalide, protocatechuic acid, shikimic acid, quinic acid, ginkgolide B, ginkgolide J, kaempferol-3-O-rutinoside, isorhamnetin-3-O-rutinoside, quercetin-3-O-ct-L-rhamnopyranocyl-2＂-（6＇＂-p-coumaroyl）-β-D-glucoside and rutin were recognized as characteristic chemical markers that contributed most to control the quality of GBEs. Based on the fact that GBEs should be standardized with the characteristic components as quality control chemical markers, it is most important to maintain the quality of GBEs stable and reliable, and this method also provided a good strategy to further rectify and standardize the GBEs market.

Comparative study on main compounds in Ginkgo biloba L. base on mathematical statistics

In this paper,an HPLC-DAD-ELSD method was developed to determine main 20 components of Ginkgo biloba L.leaves from different ages and sources,including six flavonol glycosides,five terpene lactones and nine organic acids.Using statistics method and establishing relevant mathematics models,the measured data has proceeded correlation analysis,principal component analysis,and regression statistics and the results showed generality and specific characteristics.We defined p-hydroxybenzoic acid,catechinic,KRcG and ginkgolide A as characteristic indexes representing commonness and speciality of Ginkgo biloba L.leaf.The four characteristic indexes can reflect the quality of Ginkgo biloba L.leaf,and the intermal relations between them are significant.The contents of other compounds could define the quantity relation with characteristic markers.It simplified the approach of quality control,and provided a basis for quality control of Ginkgo biloba L.

Experimental Study on Inhibition of Neuronal Toxical Effect of Levodopa by Ginkgo Biloba Extract on Parkinson Disease in Rats

In order to observe neuronal toxical effect of Levodopa and investigate if using Levodopa together with Ginkgo Bilobar Extract (EGb) would be an workable method to treat Parkinson disease, rat models of Parkinson disease (PD) were made by injecting 6-OHDA stereotaxically to right side of the mesencephic ventral tegmental area (VTA) and substantia nigra pars compacta (SNc). Rotational behavioral observation, TUNEL, immunocytochemistry, Nissl's body staining were performed to measure the difference between group treated by Levodopa (50 mg/kg every day for 3 days, 5 days, 7 days, L-dopa group) and group treated by Levodopa combined with EGb (100 mg/ kg every day, E-D group). The results showed that in the L-dopa group, the numbers of apoptosis of substantial nigra, rings of rotational behavior were more than those in the E-D group (P<0. 05). The numbers of Nissl's cells in L-dopa group were fewer than in E-D group (P<0. 05). The results suggested that Levodopa had neur toxic effect and EGb may decrease the toxicity of levodopa. The combined use of EGb with Levodopa may be a workable method to treat PD and may be better than using Levodopa alone.

Histological Observation of Somatic Embryogenesis and Adventitious Buds Induction from Ginkgo biloba L.Different Explants in vitro Culture

The differentiation process including somatic embryogenesis in different Ginkgo explants in vitro culture were studied by cytological observation.The results are as follows:1) two complete cotyledons and a embryo bud were observed in mature embryos and several secretory acavitives appeared in maturation region of embryo buds,hypocotyls,cotyledons and radicles after culturing 20 days;two incomplete cotyledons and a embryo bud primordia were found in large cotyledon embryos.The proembryo of two cells,four cells, multi-cellular,and globular embroy were developed from the callus of the small cotyledon embryos.2) The differentiation of cotyledon explants started from epidermal cells,and gradually formed meristematic cell mass in the cortical cells,and eventually adventitious buds were observed.3) The adventitious roots of Ginkgo originated in the cells at the cross of vascular cambium and vascular rays. 4) The type of rooting belongs to induction type by root primordium.The formed adventitious roots were observed after 20 days.

Biotransformation of 14-Deacetoxy-13-oxo sinenxan A by Ginkgo Cell Cultures

Deacetoxy-13-oxo sinenxan A (1) was converted to 9a-hydroxy-13-oxo-2a, 5a, 10b-triacetoxy-4(20),11-taxadiene (2) and 10b-hydroxy-13-oxo-2a,5a,9a-triacetoxy- 4(20), 11- taxadiene (3) by Ginkgo cell suspension cultures in 45% and 15% yields, respectively.

Transformation of Ginkgo Hairy Root and Establishment of Its Suspension Culture Clone

Tender leaves,buds and stems of ginkgo biloba L .were transformed successfully by Agrobacterium rhizogenes with Ri plasmid,and its suspension cultured clone was eastablished.The result of detection of opines suggested that A.rhizogenes had integrated the T DNA of the Ri plasmid into genomic DNA of ginkgo cells.A new way is offered to exploit ginkgo resources with biological technology.

Studies on Biological Characteristics of Ginkgo Hairy Root Culture

The comparative studies on properties of growth and cultivated conditions of seven transformed ginkgo hairy root clones were reported. Different clones display various phenotypes characterized by growth rate.The results show that the suitable inoculum is benefical to the growth of ginkgo hairy root.NH + 4/NO - 3, pH ,sucrose, and inositol have important effects on the growth of ginkgo hairy root.

γ-氨基丁酸/L-瓜氨酸增强白果分离蛋白凝胶性

以白果分离蛋白(GSPI)为成胶基质材料,将γ-氨基丁酸(GABA)和L-瓜氨酸(L-Cit)分别加入到GSPI水溶液中,均质后再将溶液pH分别调至5.0、6.0和7.0,制备了热诱导凝胶。采用物化分析法、机械力学、蛋白凝胶电泳、SEM及FTIR表征了溶胶的物性、凝胶性和微观结构,并探讨GABA、L-Cit对GSPI凝胶性能的影响及其机制。结果表明,GABA、L-Cit对GSPI溶解度无提升作用,但能显著降低蛋白疏水性;GABA促进溶胶聚集并降低其ζ-电位,而L-Cit在pH 7.0时则促进解聚和提高ζ-电位;两者均能促进蛋白分子疏水基团向内折叠。在pH5.0和pH7.0时,以上两种氨基酸特别是L-Cit显著提高蛋白凝胶性能,而在pH6.0时则弱化凝胶性能。其影响机制可能是氨基酸与GSPI之间的静电作用,而这种效应依赖于所在体系的pH。

利用AFLP技术筛选与银杏性别相关的分子标记

利用 amplified fragment length polymorphism(AFLP)技术 ,应用 4 8个引物组合 ,检测了雌雄银杏基因组DNA的多态性 ,筛选与银杏性别相关的分子标记 ,其中 3个引物组合各提供了 1个与雌性相关的分子标记 .经Southern点杂交证实有两个标记为银杏雌性基因组所特有 .这些分子标记的获得 ,为寻找性别特异的探针或PCR引物 。

银杏LEAFY同源基因的分离与克隆

The flower meristem identity gene LEAFY is a developmental switch,sufficient for flower initiation in diverse plants. Ginkgo biloba is a kind of gymnosperm,and a dioecious tree species.The nucleotide DNA sequence was cloned from the genomic DNA of the tender leaves collected from a male tree in Ginkgo biloba L.cv.Dafushou.The analysis of DNA sequence structure indicated that the gene was composed of 3450 bp,and inferred the sequence to LEAFY gene of the male Ginkgo .Comparing the gene with LEAFY gene of the female Ginkgo reported in the relative references,the rate of homology was 99%,only lacking 3 nucleotides.The research work laid a sound foundation for studing the regulation and controlling flowering mechanism in Ginkgo biloba L.at the molecuar level in the future.