发根农杆菌介导的菠菜毛状根遗传转化体系的建立

发根农杆菌(Agrobacterium rhizogenes)侵染植物后可诱导植物产生毛状根。菠菜(Spinacia oleracea)是常见的食用蔬菜, 目前尚未见菠菜毛状根的研究报道。经筛选得到适合诱导菠菜毛状根的发根农杆菌菌株LBA9402, LBA9402侵染菠菜外植体茎后, 毛状根的诱导率最高可达16%。菠菜毛状根呈白色, 具有丰富的根毛, 能在无外源激素的固体培养基上快速增殖生长。通过诱导菠菜毛状根产生愈伤组织并进行分化, 获得了菠菜毛状根的再生植株, 再生率为8%。此外, LBA9402可将含有Ri质粒的T-DNA和携带外源GFP基因的Ti质粒T-DNA共同导入外植体中。PCR检测和荧光显微观察结果显示, rolB及GFP基因在菠菜毛状根基因组中稳定表达, 共转化频率为50%。     

发根农杆菌介导的野葛毛状根遗传转化体系

为建立高效的野葛(Puerarialobata)毛状根遗传转化体系,以野葛组培苗为外植体,探讨不同因素对野葛毛状根遗传转化效率的影响。结果表明,基因型是建立野葛毛状根高效遗传转化体系的主要限制因子;发根农杆菌K599为最适宜的菌株;以培养5–13代组培苗继代培养8天、第1–2节位刚展开的幼嫩叶片为最佳外植体材料,预培养3天,菌液侵染15分钟,毛状根诱导率最高,可达22.4%。野葛毛状根继代增殖的最佳培养基类型为固体培养基,其毛状根鲜重是液体培养基中毛状根鲜重的75倍; PCR检测和荧光显微观察结果显示, GFP及rolB基因在野葛毛状根基因组中稳定表达,共转化率为80%。研究初步建立了发根农杆菌介导的野葛毛状根遗传转化体系,旨在为野葛基因功能研究奠定基础。     

发根农杆菌介导的金花茶毛状根活体遗传转化体系的建立

金花茶（Camellia petelotii）是我国特有的植物资源,具有较高的观赏价值和药用价值,建立转基因体系可为开展金花茶特定基因功能鉴定和金花茶性状遗传改良提供基本方法。本研究以金花茶成熟叶片为材料,分别以携带红色荧光蛋白基因DsRed2和发育调节因子GRF5的发根农杆菌（Agrobacterium rhizogenes）进行离体转化,利用石蜡切片观察叶柄切口处愈伤组织和毛状根的细胞形态。结果表明,金花茶叶柄切口处在发根农杆菌侵染后22 d时就有愈伤组织出现,72 d时生根率达到10.00%左右,而ddH₂O对照处理的金花茶叶柄切口处愈伤组织形成的时间较晚,且无毛状根产生。同时,发根农杆菌K599可将外源基因DsRed2和发育调节因子GRF5转入毛状根基因组中,转基因效率为0.83%～3.33%。石蜡切片显示GRF5转基因金花茶愈伤组织中活性细胞较DsRed2转基因愈伤组织中的多,GRF5转基因毛状根中可观察到从内皮层产生毛状根原基,内皮层及中柱鞘细胞染色程度深,细胞活性强。本研究用携带荧光蛋白和发育调节因子基因的发根农杆菌侵染金花茶离体成熟叶片的叶柄切口,诱导金花茶产生转基因毛状根,初步建立了金花茶转基因毛状根诱导体系,为后续金花茶花色和药用次生代谢物含量等性状的遗传改良提供了新思路。     

发根农杆菌诱导桑树毛状根体系的建立

应用发根农杆菌ACCC10060,以直接接种和共培养2种方法侵染桑树10 d龄子叶,并将2种处理的外植体分别接种于MS+AS(乙酰丁香酮,100 μmol/L)的平板,暗培养2 d后转接至MS+CS(头孢霉素,200 mg/L)平板培养3周,每3 d转接1次以除去其中所含的发根农杆菌菌体,结果2种侵染方法均成功诱导桑树产生毛状根,诱导效率分别为14%和17%.在无激素MS培养基上离体培养除菌后的毛状根,呈现旺盛的生长态势和典型的发状根结构特点.CTAB法提取毛状根基因组并进行PCR检测,结果扩增出了423 bp的rolB基因片段,表明Ri质粒的T-DNA已经成功整合到桑树的基因组中.     

发根农杆菌介导的药用植物遗传转化研究

利用发根农杆菌(Agrobacterium rhizogenes)诱导药用植物产生的毛状根具有生长迅速,合成能力强和遗传性稳定等优点,已成为一种新的培养系统。就影响发根农杆菌介导的药用植物遗传转化的因素作一概述。     

发根农杆菌介导的尾巨桉遗传转化体系的建立

发根农杆菌（Agrobacterium rhizogenes）的建立对植物功能基因的验证具有重要意义,为了在桉树（Eucalyptus）中建立发根农杆菌介导的遗传转化体系,本研究以不同的发根农杆菌菌株侵染尾巨桉（Eucalyptus urophylla × E. grandis）的叶片和茎段,确定合适的农杆菌菌株和外植体类型,在此基础上开展农杆菌浓度、侵染时间对毛状根诱导的影响。结果表明：采用发根农杆菌菌株MSU440,以叶片为外植体进行发根诱导,最高获得了81.0%的毛状根诱导率,毛状根平均根长达到3.23 cm。在发根农杆菌浓度为OD₆₀₀=0.3、侵染时间为30 min时,共培养48 h后经过20 mg·L^-1卡那霉素筛选培养,通过PCR分子鉴定和GUS染色证实外源基因稳定地整合在桉树毛状根基因组中,转化率达20.2%。初步建立了发根农杆菌介导的桉树遗传转化体系,为桉树基因功能鉴定和进一步的转基因育种奠定基础。     

发根农杆菌介导的药用植物遗传转化研究进展

发根农杆菌介导的植物遗传转人旨近年来发展起来的一项新的植物遗传转化技术。本文就发根农杆菌Ｒ１闰的结构、发根农杆菌介导的植物遗传转化的方法和步骤,以及运用这一技术获得药用植物次生代谢产物的研究进展作一全面介绍。     

发根农杆菌介导的野葛毛状根遗传转化体系

为建立高效的野葛(Pueraria lobata)毛状根遗传转化体系, 以野葛组培苗为外植体, 探讨不同因素对野葛毛状根遗传转化效率的影响。结果表明, 基因型是建立野葛毛状根高效遗传转化体系的主要限制因子; 发根农杆菌K599为最适宜的菌株; 以培养5-13代组培苗继代培养8天、第1-2节位刚展开的幼嫩叶片为最佳外植体材料, 预培养3天, 菌液侵染15分钟, 毛状根诱导率最高, 可达22.4%。野葛毛状根继代增殖的最佳培养基类型为固体培养基, 其毛状根鲜重是液体培养基中毛状根鲜重的75倍; PCR检测和荧光显微观察结果显示, GFP及rolB基因在野葛毛状根基因组中稳定表达, 共转化率为80%。研究初步建立了发根农杆菌介导的野葛毛状根遗传转化体系, 旨在为野葛基因功能研究奠定基础。     

发根农杆菌对黄瓜的遗传转化

发根农杆菌对黄瓜的遗传转化施和平李玲潘瑞炽（华南师范大学生物系广州５１０６３１）关键词发根农杆菌,黄瓜,毛状根,冠瘿碱ＧＥＮＥＴＩＣＴＲＡＮＳＦＯＲＭＡＴＩＯＮＯＦＣＵＣＵＭＩＳＳＡＴＩＶＵＳＢＹＡＧＲＯＢＡＣＴＥＲＩＵＭＲＨＩＺＯＧＥＮＥＳＳＨＩ...     

激素对转基因雪莲毛状根植株再生及类黄酮产生的影响

为了研究外源激素GA3和IAA对3个转基因新疆雪莲类黄酮高产毛状根系C17、C27、C46的植株再生及其总黄酮含量的影响,在培养基中添加不同浓度的GA3和IAA,结果发现,GA3浓度高于1.0 mg/L时,可诱导毛状根系产生不定芽,其中以GA3浓度为2.0 mg/L时,转基因毛状根系C17的不定芽再生率最高,可达82％。高压液相色谱以及紫外分光光度法测定结果表明,与未用激素处理的毛状根和它的再生植株相比,外源激素GA3和IAA能显著提高毛状根培养物中芹菜素和总黄酮的含量。毛状根系的组织干重与类黄酮的含量没有相关性,但毛状根系的再生率与类黄酮的含量几乎呈反相关性。     

Plant regeneration from cell suspensions of spinach

Friable calluses induced from root segments of spinach (Spinacia oleracea L.) with a high amount of growth regulators (indole-3-acetic acid 48.52 μM and gibberellic acid 10 μM) were suspended in liquid medium. The cell fraction sized between 100 and 200 μm was used to establish suspension cultures. Adventitious shoots and roots were obtained from the suspensions (3.2 x 10⁵ cells per ml) by procedures comprising successive subcultures on two or three different media. In both of these procedures, the composition of the second culture medium (concentrations of plant growth regulators) had a key influence on the organogenesis of the suspensions. Regenerated shoots elongated and rooted on different solid media. Plantlets transplanted in soil grew and developed normally until flowering and produced seeds. This revised version was published online in June 2006 with corrections to the Cover Date.     

Isolation of plasma membrane and tonoplast fractions from spinach leaves by preparative free-flow electrophoresis and effect of photoinduction

A membrane fraction enriched in plasma membrane and tonoplast vesicles was isolated from green leaves of Spinacia oleracea L. and subjected to subfractionation by free-flow electrophoresis. The most electronegative membrane vesicle fraction collected after the free-flow electrophoretic separation was identified as derived from tonoplast, while the least electronegative fraction was identified as derived from plasma membrane. The identification of the fractions was based on membrane morphology, and on the presence or absence of biochemical markers. The plasma membrane fraction was enriched in thick (9–11 nm) membranes which bound N-1-naphthylphthalamic acid (NPA), and reacted with phosphotungstic acid at low pH on thin sections for electron microscopy. The tonoplast fraction was enriched in vesicles with 7–9 nm thick membranes that neither bound NPA nor reacted with phosphotungstic acid at low pH. Both the plasma membrane and the tonoplast fraction were about 90% pure, with a cross-contamination of not more than 2%. Membrane vesicles originating from dictyosomes, endoplasmic reticulum, mitochondria, plastids, or peroxisomes contaminated the plasma membrane and the tonoplast fractions by a few % only. In leaves of photoinduced plants (24 h light period), the plasma membranes were thicker than in control leaves (8 h light, 16 h dark). The plasma membrane fraction obtained from photo-induced leaves by free-flow electrophoresis retained this increase in thickness, showing not only that photoinduction alters plasma membrane structure, but also that this change is stable to isolation.     

农杆菌转化的小冠花发状根的诱导及其植株再生

利用野生型发根农杆菌15834菌株感染小冠花15日龄无菌苗子叶和下胚轴切段,建立了高效的发状根培养及其体细胞胚胎发生再生体系。发状根可直接从受伤的外植体表面产生,也能在外植体诱导的愈伤组织上发生,在无外源激素的MS固体和液体培养基上,转化根能自主生长,表现出典型的发根特征。用适宜浓度的乙酰丁香酮处理对数生长期的农杆菌菌液2h,感染预培养2d的子叶获得了最高的转化频率(87.4%)。在附加0.2mgL2,4_D,0.5mgLNAA和0.5mgLKT的MS培养基上,发状根能100%形成胚性愈伤组织,并于含0.5mgLKT,0.2mgLIBA和300mgL脯氨酸的MS培养基上顺序经过体细胞胚胎发育的各个典型时期,转换成完整植株。再生植株除具有发达的侧根外,其它形态特征与未转化植株未见明显的差异,但在获得的5个转化克隆中,其中1个的发状根及其再生植株叶片中有毒物质3_硝基丙酸的含量显著下降,分别为未转化对照的57.68%和58.17%。冠瘿碱纸电泳检测和rolB基因PCR扩增检测均证明农杆菌Ri质粒上的T_DNA已经整合到小冠花转化细胞的基因组中。     

Comparison of properties of leaf and root glutathione reductases from spinach

Glutathione reductase (GR; EC 1.6.4.2) was purified from spinach roots (rGR) to homogeneity in terms of SDS-PAGE, and its properties were compared with those of the enzyme from spinach leaves (IGR). The two enzymes had similar native molecular (118000) and subunit masses (58000) and immunochemical properties, but different pH optima (ca pH 7.8 for IGR, ca pH 7.2 for rGR) and amino acid compositions. Peptide maps of two GRs showed that they differed from each other. The N-terminal amino acid of the IGR was glycine and that of the rGR was blocked. The partial amino acid sequence of the N-terminal region of the IGR was determined to the 11 th residue and it was found that the sequence of 8 amino acids of the IGR had 100% homology with that of the putative chloroplast GR from Arabidopsis and pea.     

甘蓝下胚轴原生质体再生植株

经纯化后,甘蓝下胚轴原生质体的产量为1．5×10⁶g^-1(Fw),采用液体浅层培养的方法进行培养。2～3d后,发生第一次分裂,第10天,统计分裂频率为6l％,5周内形成大量的细胞团和小愈伤组织,统计植板率为1．1％,把小愈伤组织转到与原生质体培养基相同激素的MS固体培养基上增殖。当愈伤组织长到3～5mm大小时,接到分化培养基上,芽分化率为46.7％．分化出来的芽长到3～4cm长时,从基部切下,插入生根培养基,两星期左右即可长成完整植株。