Somatic embryogenesis and plant regeneration in zygotic embryo cultures of balloon flower

Mature zygotic embryos of balloon flower (Platycodon grandiflorum) formed embryogenic calluses at a frequency of 43% when cultured on Murashige and Skoog medium supplemented with 4.52 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Cell suspension cultures were established from embryogenic calluses using MS liquid medium with 4.52 μM 2,4-D. Following transfer to solid MS basal medium, cell suspension cultures gave rise to somatic embryos, which then developed into plantlets. Plantlets were transplanted to potting soil and grown to maturity. This revised version was published online in June 2006 with corrections to the Cover Date.     

A homogalacturonan from the radix of Platycodon grandiflorum and the anti-angiogenesis activity of poly-/oligogalacturonic acids derived therefrom

A polysaccharide, PGA4-3b, with an average molecular weight of 8.9 kDa estimated by high-performance gel-permeation chromatography (HPGPC), was isolated from radix of Platycodon grandiflorum (Jacq.) A. DC. Using monosaccharide analysis, methylation analysis and NMR spectroscopy, PGA4-3b was elucidated to be a linear poly-(1→4)-α-d-galactopyranosyluronic acid that contains no methyl ester groups. Partial acid hydrolysis of PGA4-3b yielded a series of poly- or oligogalacturonic acids with different degrees of polymerization (DP), that is, 4-3bde, 4-3bde-O-1, 4-3bde-O-2, 4-3bde-O-3, and 4-3bde-O-4. Cell tube formation inhibition tests with human microvascular endothelial cells (HMEC) for antiangiogenesis analysis showed that 4-3bde-O-1 and 4-3bde-O-2, the fractions with higher molecular weights, could inhibit tube formation, while the native PGA4-3b and low molecular weight fraction 4-3bde-O-3 and 4-3bde-O4 are ineffective. Moreover, 4-3bde-O-2 with DP 5-10 impaired cell tube formation in a dose-dependent way, suggesting its potential to be developed as an anti-angiogenesis drug. This is the first time oligogalacturonic acids are reported to show an anti-angiogenesis effect.     

桔梗水浸提液对小麦幼苗的化感作用

采用培养皿滤纸法研究了不同浓度桔梗水浸提液对小麦的幼苗生长及生理生化指标的影响,探讨桔梗植株水浸提液对小麦的化感作用,推测其可能的生理机制。结果表明：桔梗植株水浸提液对小麦幼苗的地上部生长表现为低浓度（≤1mg／mL）促进、高浓度（5—20mg／mL）抑制作用;对根部生长为抑制作用,且抑制强度大于地上部。随处理浓度的升高,小麦幼苗体内POD活性、脯氨酸含量、MDA含量逐渐升高;CAT活性、根系活力、光合色素含量先升高后降低;可溶性蛋白含量和伤害率先降低后升高。桔梗植株水浸提液对小麦总体的化感效应表现为低促高抑,小麦可作为桔梗的轮作作物种植。     

桔梗科4种植物分离配囊的比较研究

应用酶解技术分离出桔梗科四种植物(桔梗、轮叶沙参、杏叶沙参和羊乳)的胚囊。对胚囊的形态结构和贮藏物质的变化作了观察比较。它们的成熟胚囊结构基本相同,均由卵细胞、一对助细胞和中央细胞组成。反足器退化较早。但形态、大小等有一定差异。桔梗胚囊狭长,细胞质浓密;沙参(包括轮叶沙参与杏叶沙参)的胚囊也较狭长,细胞质不如前者浓密;羊乳胚囊非常宽大,而细胞质相当稀薄,与前三种植物的差异较大。它们均含有贮藏物质,显微化学反应表明主要系多糖物质。多糖颗粒的形状、大小各有特点,在胚囊受精前后的消长变化也有不同。其中羊乳与其它三种植物之间的差别较大。     

桔梗内生真菌的分离鉴定及其生物学特性研究

为了解药用植物桔梗(Platycodon grandiflorum)内生真菌的组成情况,利用组织分离法,从桔梗的根部分离得到菌落形态一致的链格孢菌,根据其形态特征及生物学特性,鉴定为桔梗链格孢(Alternaria platycodonis T.Y.Zhang)。     

桔梗雄性不育花药的发育解剖学研究

通过田间观察和石蜡切片法对桔梗不育和可育花药的形态及其解剖结构进行了比较研究,结果表明:桔梗可育和不育花器形态、花药长度无明显差异,而开花后,可育花药饱满、有光泽、有花粉粒散出,不育花药皱瘪、无光泽、无花粉粒散出;不育花药绒毡层提前退化解体,导致小孢子发育异常。     

桔梗RAPD反应体系的优化

以通化桔梗为材料,用改进的CTAB法提取桔梗叶片的总DNA,通过对不同镁离子浓度、dNTP浓度、模板DNA含量、引物浓度、DNA聚合酶量条件下的RAPD扩增反应的效果,建立了一个适合桔梗的比较稳定的RAPD反应体系,用于桔梗遗传多样性分析。结果表明,桔梗RAPD扩增反应的最佳体系为:模板DNA20ng,dNTP150μmol/L,引物0.3μmol/L,Mg2+浓度2.0mmol/L,TaqDNA聚合酶1Unit,10×Buff-er2.0μL,PCR反应总体积为20μL。按此优化RAPD条件进行实验,重现性良好。     

Biotransformation of chinensiolide B and the cytotoxic activities of the transformed products

Biotransformation of chinensiolide B, 10α-hydroxy-1α,5α,15-H-3-oxoguaia-11(13)-en-6α,12-olide (1), yielded three selectively reduced products, 3β,10α-dihydroxy-1α,5α,15α-H-guaia-11(13)-en-6α,12-olide (2), 3α,10α-dihydroxy-1α,5α,15α-H-guaia-11(13)-en-6α,12-olide (3), and 3β,10α-dihydroxy-1α,5α,11β,15α-H-guaia-6α,12-olide (4) by the cell suspension cultures of Catharanthus roseus. 2 and 3 were also obtained from 1 incubated with cell cultures of a fungus Abisidia coerulea IFO 4011 and Platycodon grandiflorum, respectively. Among them, 2, 3 are two new compounds. The three products, 2–4, along with 1 were preliminarily evaluated for their in vitro cytotoxic activity against 3 cell lines (HepG2, WI-38 and VA-13) and all showed potent inhibitory effects on the cell proliferation. Of the four compounds, 3 was the most toxic to the three cell lines tested with IC₅₀ values of 22.7, 0.33 and 3.30 μM, respectively.     

桔梗花粉萌发与花粉管生长研究

以2年生桔梗植株为材料,采用液体培养法研究了培养基种类、PEG、蔗糖、pH以及培养温度、培养时间对桔梗花粉离体萌发生长的影响,结果表明:(1)浓度为100~150 g.L-1的PEG可显著促进桔梗花粉萌发和花粉管的生长;200~250 g.L-1PEG显著促进花粉萌发,但对花粉管生长的作用不显著。(2)100 g.L-1的蔗糖有利于花粉萌发和花粉管生长,高浓度蔗糖(200 g.L-1)有明显抑制作用;(3)桔梗花粉离体萌发和花粉管生长的适宜培养基为ME3+BK+10%蔗糖+150 g.L-1PEG(pH5.8);(4)25~40℃条件下桔梗花粉均可较好萌发,以30℃培养1.5 h为最佳培养条件。     

桔梗的核型研究

本文观察和分析了桔梗的体细胞染色体,2n=18,核型公式为K(2n)=10m+8sm(2SAT),有较高的对称性,属“2A”型,在桔梗科中处于较为原始的地位。它与近缘属似有基数渐减的进化趋势。