发根农杆菌LBA9402 Bin19转化红豆草及再生转基因植株

用含pBin19和pRi1855的发根农杆菌菌株对红豆草下胚轴切段进行遗传转化,种苗年龄和下胚轴切段的预培养时间明显影响转化频率.纸电泳分析表明70%的发状根培养系能够合成农杆碱.发现发状根诱导愈伤组织比发状根具有更强的再生力;发状根切段在含0-9.05μmol/L2,4-D和0-2.22μmol/L6-BA的MS培养基上诱导产生愈伤组织,然后在不含植物激素和卡那霉素的MS培养基上进行再生试验.愈伤组织诱导培养基中的植物激素组成和浓度显著影响愈伤组织后期的再生植株能力.再生频率和每块愈伤组织的芽点发生数随愈伤组织诱导培养基中2,4-D浓度的增加(4.52-9.05μmol/L)而下降,随6-BA浓度增加(0-2.22μmol/L)而上升.在附加4.52μmol/L2,4-D和2.22μmol/L6-BA的MS培养基上,愈伤组织的诱导频率只有14.2%,但愈伤组织在MS0培养基上的再生频率高达58.1%,每块愈伤组织的芽点发生数平均为37.2.对来自8个发状根系的32株再生植株进行Southern分子杂交分析,25株整合有不同拷贝的nptⅡ基因.     

香石竹毛状根诱导、离体培养及其植株再生

为了探讨利用发根农杆菌遗传转化所产生的毛状根来创新香石竹种质的可能性,本文采用叶盘法,建立了发根农杆菌Agrobacterium rhizogenes对香石竹Dianthus caryophyllus L.叶片外植体的遗传转化及其植株再生体系。结果表明,发根农杆菌ATCC15834感染香石竹幼嫩叶片外植体12 d后,从叶片外植体切口中脉处产生白色毛状根,21 d后约90%的叶片外植体产生毛状根。所获得的无菌毛状根能在无外源激素的MS固体和液体培养基中快速自主生长。PCR扩增和硅胶薄层层析结果显示发根农杆菌Ri质粒的rol B和rol C基因以及冠瘿碱合成酶基因已在香石竹毛状根基因组中整合并得到表达。将毛状根置于MS+6-BA 1.0-3.0 mg/L+NAA 0.1-0.2 mg/L中培养15 d后产生淡黄绿色的疏松愈伤组织。愈伤组织不定芽分化的最适培养基为MS+6-BA 2.0 mg/L+NAA 0.02 mg/L,培养6周后不定芽分化率为100%;平均每个愈伤组织产生30-40个不定芽;将不定芽转至1/2 MS或1/2 MS+0.5 mg/L NAA的培养基中10 d后产生不定根,发育成再生植株。再生植株移植于栽培基质中20 d后,成活率达95%以上。     

发根农杆菌对骆驼刺的转化及转化组织的形态发生

将骆驼刺离体再生苗的茎切段经发根农杆菌A4菌株感染后,在含500mg/L头孢霉素的MS无激素培养基上培养,产生了转化的发根和愈伤组织.转化根在附加2mg/L2,4-D和0.5-1mg/L6BA的MS培养基上培养后,亦可诱导出愈伤组织.在含3mg/L6BA和0.5mg/LNAA的培养基上诱导出了苗的分化.冠瘿碱分析表明,在95%以上的发根和75%的转化愈伤组织及再生植株中都显示了T-DNA的整合和表达.染色体检查发现,约81%的发根细胞具有正常染色体数(2n=18),其余则存在染色体数目的变化,在继代培养一年之后,转化体仍维持旺盛的再生能力.     

发根农杆菌转化怀地黄再生植株

利用发根农杆菌15834菌株感染怀地黄组培苗子叶、叶柄和茎切段,建立了有效的毛状根培养及其植株再生体系。毛状根可直接从受伤的外植体产生,能在无外源激素的1/2MS固体和液体培养基上自主生长,表现出典型的发根特征。用100μmol/L乙酰丁香酮处理对数生长期的农杆菌菌液感染子叶获得了46.7%的最高转化频率;在附加0.2mg/L KT和3.0mg/L 6/BA的1/2 MS培养基上,毛状根能100%形成愈伤组织,51.49%分化出芽;分化芽在1/2 MS培养基上100%生根,形成具有矮化、节间短和根系发达等特征的转化再生植株且移栽后生长旺盛;1个转化毛状根克隆的梓醇含量为0.557mg/g,是鲜地黄梓醇含量的48.5%,是生地鲜重梓醇含量的18%。rolB基因PCR、Southem blot分析、冠瘿碱纸电泳和RT-PCR扩增检测证明农杆菌Ri质粒上的T-DNA整合到怀地黄基因组中并表达。     

荞麦高频离体再生及发根农杆菌转化体系的建立

荞麦无菌苗下胚轴切段在不同激素配比的MS培养基上诱导愈伤组织,出愈率均为100％。在2．0mg/L2,4-D和1．5mg/L 6-BA组合下诱导产生的愈伤组织;转入2．0mg/L 6-BA和1．0mg/L KT的MS培养基,再生苗分化率在80％以上。根尖色体分析表明再生植株具一定的遗传稳定性。发根农杆菌A4转化荞麦下胚轴和子叶获得发状根,纸电泳检测所有随机取样测定的发状根均有相应冠瘿碱的存在。     

发根农杆菌转化大豆的研究

本文利用发根农杆菌感染大豆不同外植体,在成熟胚靠近子叶节部位诱导产生毛状根。经冠瘿碱检测表明,毛状根及由此产生的愈伤组织均有甘露碱存在,说明Ri质粒的T-DNA已整合到大豆的转化根及愈伤组织中。转化根再生实验表明,在含NAA和IAA8mg/L的MS培养基上得到不定根的分化,MS和B_3培养基及6％蔗糖对转化丛生芽的诱导有利。转化的丛生芽在MS基本培养基上进一步长成小植株。     

五寸石竹毛状根诱导及其植株再生

建立了五寸石竹(Dianthus chinensis)毛状根诱导及其植株再生体系。用含野生农杆碱型Ri质粒的发根农杆菌(Agrobacterium rhizogenes)15834感染五寸石竹叶片外植体10天后,从其形态学下端产生白色不定根;30天后,叶片外植体的生根率为95%;所产生的毛状根能在无外源生长调节剂的固体和液体MS培养基上快速自主生长。遗传转化鉴定结果表明,发根农杆菌Ri质粒的生根基因(rol)已在毛状根基因组中整合并表达。五寸石竹毛状根的根段在成分为MS+2.0 mg·L~(–1)6-BA+0.2 mg·L~(–1) NAA的培养基中培养15天后产生浅绿色疏松愈伤组织;将愈伤组织转入成分为MS+1.0 mg·L~(–1) 6-BA+0.02 mg·L~(–1) NAA的培养基中培养30天后逐渐形成不定芽。盆栽的五寸石竹毛状根再生植株与非转化植株(对照)相比节间缩短,开花期提前18天。     

除虫菊发状根的诱导及培养条件优化

以除虫菊（Pyrethrum cinerariifolium Trey.）无菌苗为外植体,研究除虫菊发状根的诱导、培养条件优化,并对发状根中的除虫菊素进行检测和生物活性测定。结果显示,乙酰丁香酮能促进除虫菊下胚轴和子叶发状根的诱导,当乙酰丁香酮浓度为150 μmol/L时除虫菊下胚轴和子叶的诱导率为对照的2.29倍和2.66倍,预培养6 d时,下胚轴发状根诱导率为对照的2.25倍,发根农杆菌A4的诱导率均高于ATCC15834,愈伤组织较适合发状根的诱导,愈伤组织侵染后适合在无激素的MS培养基上进行发状根诱导,250 mL三角瓶中添加50 mL MS培养基较适合发状根的生长。对除虫菊发状根进行PCR检测发现,发根农杆菌含有的Ri T-DNA的rolB基因已整合进入发状根基因组中。通过GCMS检测发现,愈伤组织中除虫菊素的6种成分均未检测到,而发状根中检测到瓜菊素Ⅰ、茉酮菊素Ⅰ和茉酮菊素Ⅱ 3种成分,发状根对粘虫的拒食作用明显优于愈伤组织。本研究为通过组织培养方式生产除虫菊素奠定了基础。     

Ri质粒介导GUS基因转化商陆的研究

发根农杆菌Ar1334工程菌株与商陆叶片共培养,诱导效率不同程度地受到发根农杆菌生理状态、浓度、浸泡时间、共培养时间的影响:采用稀释5倍的处于对数生长期的Ar1334工程菌株,感染商陆无菌苗幼嫩叶圆片5min,在MS培养基上共培养2d,可达最大转化效率82.2%;诱导的根在附加20mg·L-1Kan的MS无激素MS培养基上,呈现旺盛的生长态势和典型的发状根结构特点,经PCR检测扩增出了560bp的rolC基因的目的片断,组织化学检测也证实了GUS基因在发状根中的表达.     

发根农杆菌诱导玉米毛状根发生及再生植株

发根农杆菌(Agrobacterium rhizogenes)侵染玉米愈伤组织15天左右获得毛状根. 转化根在不含激素的培养基上快速生长, 并表现出典型的毛状根性状. 在含ZT 1.6 mg/L和NAA 0.4 mg/L的MS培养基上, 毛状根再生成完整转化植株. PCR-Southern杂交证实T-DNA已整合入转化株的染色体组.     

Agrobacterium rhizogenes-mediated transformation and the regeneration of transformants in Alhagi pseudalhagi]

The regenerated shoot segments of Alhagi pseudalhagi were sliced and infected with Agrobacterium rhizogenes strain A4. The hairy roots and transformed calli were obtained through selection on hormone free MS medium. The transformants were cultured on MS medium with 2 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) and 0.5-1 mg/L 6-benzylaminopurine (6-BA) to induce calli. 3 mg/L 6-BA and 0.5 mg/L naphthalene acetic acid (NAA) were applied for shoot differentiation. Shoots were planted on MS medium with 2 mg/L indole-3-butyric acid (IBA) and produced roots. Opine analysis proved the integration and expression of T-DNA in over 95% hairy roots, 75% transformed calli and transformed plantlets respectively. The 81% hairy root cells had normal chromosome numbers (2n = 18). The alterations of chromosome number were observed. After one year of subculturing, the regeneration ability of transformants was maintained.     

Genetic Transformation of Brassica juncea var. tsatsi Induced by Ri T-DNA of Agrobacterium rhizogenes

Hairy roots of mustard (Brassica juncea var. tsatsi) cv. "Paoye' were obtained from in vitro inoculation of reversely inserted petioles with Agrobacteriurn rhizogenes strain LBA9402 harbouring the agropine-type Ri plasmid (pRi1855). The root inducing rate was 100%. Transformed roots grew rapidly on hormone-free MS medium and showed typical hairy root phenotype. Transformed plantlets regenerated from hairy roots on MS medium supplemented with BA 8.0 mg/L and NAA 0.6 mg/L. Opine analysis evidenced the integration and expression of TR-DNA, PCR analysis and Southern hybridization confirmed the integration of TL-DNA including 862 bp rol B sequence in the transformed plants.     

烟草毛状根多倍体诱导及其植株再生

为了提高烟草的烟碱含量,采用发根农杆菌遗传转化和人工染色体加倍技术,进行了烟草毛状根及其多倍体诱导、植株再生及其烟碱含量测定。结果表明,发根农杆菌ATCC15834感染烟草叶片外植体8 d后产生白色毛状根,15 d后所有叶片外植体产生毛状根。毛状根能在无外源激素的MS固体和液体培养基上自主生长。PCR扩增结果显示发根农杆菌Ri质粒的rol B和rol C基因以及冠瘿碱合成酶基因已在烟草毛状根基因组中整合并得到表达。烟草毛状根多倍体诱导的最适条件为0.1%的秋水仙素溶液处理36 h,其多倍体诱导率为64.71%。经秋水仙素加倍的烟草毛状根多倍体植株再生的最适宜培养基为MS+6-BA 2.0 mg/L+NAA0.2 mg/L。与对照(二倍体非转化植株)相比,烟草二倍体毛状根再生植株的顶端优势减弱,腋芽增多,叶片变窄;而烟草毛状根多倍体再生植株茎更粗,节间变短,叶色更深,叶片的宽度和厚度均较对照明显增大。根尖细胞染色体压片观察证实,所获得的烟草毛状根多倍体再生植株为四倍体,其根尖细胞染色体数约为4n=96。盆栽实验表明,烟草二倍体毛状根植株和多倍体毛状根再生植株比对照植株延迟约21 d开花。GC-MS检测表明,烟草毛状根多倍体再生植株的烟碱含量比对照及二倍体毛状根再生植株显著提高,分别约为对照及二倍体毛状根再生植株的6.90倍和4.57倍。     

发根农杆菌LBA9402Bin19转化红豆草及再生转基因植株

Hypocotyl segments of Onobrychis viciaefolia were transformed by Agrobacterium rhizogenes LBA9402 which harboured pBin19 and pRi1855. Seedling age and preculture time of hypocotyl segments influenced the transformation frequency. Paper electrophoresis revealed that 70% of single hairy root cultures could synthesize agropine. Calli were induced from hairy root segments on MS medium containing 0-9.05 mumol/L 2,4-D and 0-2.22 mumol/L 6-BA at first, then they were transferred onto MS0 medium without kanamycin for regeneration. Constitution and concentration of phytohormones in callus induction media affected subsequent regeneration of calluses on MS0 medium remarkably. Regeneration frequency and shoot number per callus declined when 2,4-D concentration in callus induction media increased from 4.52 to 9.05 mumol/L, while they ascended when 6-BA in callus induction media increased from 0 to 2.22 mumol/L. On MS medium supplemented with 4.52 mumol/L 2,4-D and 2.22 mumol/L 6-BA, only 14.2% hairy root segments could produce calluses, but the regeneration frequency reached 58.1% and the shoot number per callus was 37.2. In 32 analysed plants regenerated from 8 kanamycin resistant hairy root lines, 25 were nptII positive and showed different copy numbers.     

新疆雪莲毛状根的诱导及其植株再生体系的建立

利用发根农杆菌R1601、R1000、LBA9402感染新疆雪莲的叶片、叶柄和根段外植体,诱导产生毛状根。毛状根接种量为2.8 g/L(FW)时,20d生长量可达66.7 g/L,黄酮含量达到干重的10.23%。冠瘿碱的检测和rolB基因的PCR分析表明,Ri质粒中的T_DNA片段已经整合到毛状根细胞的基因组中。预培养时间、外植体类型以及发根农杆菌的菌株属性对毛状根诱导有着重要的影响。其中预培养2 d的新疆雪莲根段外植体,经过R1601感染后,毛状根的诱导率可达100%。诱导产生的毛状根在附加生长素的液体培养基中,有少量愈伤组织产生。由毛状根再生的植株与雪莲外植体再生的植株在形态上无明显区别,但前者的黄酮含量仅为后者的53%。     

Cucurbita pepo L. can be transformed by Agrobacterium rhizogenes

Two-week-old in vitro grown Cucurbita pepo L. intact plants and cotyledons (detached and undetached from the mother-plant) were transformed by Agrobacterium rhizogenes strain NCPPB 1855, grown for 48 h at 25 °C on YMB medium. All infected material formed vigorous hairy roots in about seven days. The transformed roots were successfully grown in liquid MS medium without plant growth regulators for an indefinite number of transfers. Genetic transformation of root DNA was proven by Southern analysis performed with a rolABC probe and a vir probe. Our results demonstrate that, in contrast with previous literature, A. rhizogenes could represent an efficient and reproducible system to transform C. pepo plants. Furthermore, we verified that plant age and incubation times/temperatures of bacterial strain influence transformation efficiency. This revised version was published online in June 2006 with corrections to the Cover Date.