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。     

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。     

3种农杆菌对茶树发状根诱导的影响

以茶树‘福云6号’和‘铁观音’成熟种子下胚轴、未成熟种子下胚轴和愈伤组织为材料,以发状根诱导率为指标,探究菌液浓度、农杆菌菌株、外植体类型和预培养时间对发状根诱导的影响。结果表明:(1)菌液浓度OD600在0.4~1.2范围内,‘福云6号’成熟种子下胚轴发状根诱导率先升高后降低,ATCC15834在OD600为0.6时发状根诱导率最高为23.96%,A4和K599在OD600为0.8时,发状根诱导率最高,分别为10.51%和13.11%。(2)3种发根农杆菌致根能力不同,ATCC15834侵染力最强,致根能力大小依次为ATCC15834>K599>A4。(3)发状根诱导率与外植体有关,茶树成熟种子下胚轴可被诱导产生发状根,诱导率‘福云6号’大于‘铁观音’,未成熟种子下胚轴和愈伤组织难以产生发状根。(4)不经预培养和预培养时间为1~2 d的愈伤组织易褐变,无法产生发状根;预培养3 d的愈伤组织经侵染可产生发状根,诱导率为1.85%(‘福云6号’)和0.59%(‘铁观音’)。(5)PCR琼脂糖凝胶电泳检测和GUS组织化学染色证实GUS基因已被整合进‘福云6号’和‘铁观音’愈伤组织和成熟种子下胚轴发状根基因组中并表达。研究发现,发根农杆菌ATCC15834在OD600为0.6时,对茶树‘福云6号’成熟种子下胚轴发状根诱导率最高。该研究结果对改进发根农杆菌介导的茶树遗传转化系统提供理论依据,对茶树高效遗传转化体系的优化和新型受体的开发具有重要意义。     

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.     

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.     

苦荞胚性愈伤组织诱导与植株再生研究

以苦荞子叶和下胚轴为外植体,进行了不同浓度激素组合的MS和SH固体培养基对胚性愈伤组织诱导及植株再生的研究。结果发现,MS培养基比SH培养基更有利于胚性愈伤组织诱导;2,4-D是诱导愈伤组织的有效激素,KT能有效促进胚状体的形成;下胚轴和子叶都能有效诱导出胚性愈伤组织和再生植株。下胚轴在MS 1.5mg·L-12,4-D 1.5mg·L-1BA培养基,子叶在MS 2mg·L-12,4-D 0.5~1.5mg·L-1BA上能高效诱导出愈伤组织;愈伤组织在MS 2mg·L-12,4-D 0.1mg·L-1KT培养基中继代,能有效诱导胚性愈伤组织;来自下胚轴的胚性愈伤组织在1/2MS 2.0mg·L-1BA 0.5mg·L-1KT 0.1mg·L-1NAA培养基上能够高频再生出芽,来自子叶的胚性愈伤组织在1/2MS 1.0mg·L-1BA 0.1mg·L-1KT 0.1mg·L-1NAA培养基上芽诱导率较高;MS 1mg·L-1NAA是适宜的再生苗生根培养基。     

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。     

白刺花胚性愈伤组织诱导及体细胞胚发生和萌发

探讨不同因素对白刺花下胚轴、子叶2种外植体胚性愈伤组织诱导及体细胞胚发生和萌发的影响。以B5和MS为基本培养基,研究2,4-D、6-BA和TDZ对白刺花下胚轴和子叶胚性愈伤组织的诱导;在MS培养基上添加不同浓度2,4-D,研究胚性愈伤组织增殖情况;采用ABA,探究对体细胞胚发生的影响。结果表明:下胚轴比子叶更易诱导胚性愈伤组织,筛选出2种外植最佳的胚性愈伤组织诱导培养基均为MS+2.0 mg/L 2,4-D+0.5 mg/L TDZ+0.5 mg/L 6-BA,胚性愈伤组织诱导率分别为77.3%和41.0%。15.0 mg/L ABA、0.2 mg/L 2,4-D和2.0 mg/L 6-BA有利于体细胞胚发生,1/3MS+0.2 mg/L NAA+0.1 mg/L 6-BA+2.0 g/L活性炭+25 g/L蔗糖+7 g/L琼脂的培养基可使体细胞胚萌发率达80%以上,再生植株移栽成活率高达90%。白刺花外植体种类及培养基类型均会影响胚性愈伤组织的诱导,其中下胚轴诱导效果优于子叶;MS培养基较适合启动细胞脱分化形成愈伤组织,2,4-D对胚性愈伤组织的增殖保持有调控作用,ABA有利于体细胞胚的发生。     

发根土壤杆菌体外转化甘草子叶及下胚轴

利用发根土壤杆菌农杆碱型15834、A_4菌株和甘露碱型8196、K_(599)菌株体外转化甘草子叶及下胚轴。结果表明:除K_(599)菌株外,其余三种菌株都能诱导产生甘草发状根无性系。其中15834菌株的诱导率最高,下胚轴的诱导率高于子叶。组织学观察表明,在感染后4天左右,下胚轴维管束鞘外细胞、特别是形成层部分细胞大量启动形成分生细胞及分生细胞团,并进一步分裂形成根原基。6—8天后根原基具单向极性生长形成完整的发状根结构。发状根能在无外源激素的培养基上迅速生长。高压纸电泳检测到发状根中存在农杆碱及甘露碱,说明Ri质粒T-DNA编码的这两种冠瘿碱合成酶基因在甘草细胞中得到了表达。     

宁夏枸杞发根农杆菌转化系的建立及影响转化因素的研究

以发根农杆菌Ａ４菌株介导,对宁夏枸杞叶片和茎切段的遗传转化进行了初步研究,建立了发状根体系,并优化了转化条件。乙酰丁香酮的添加、农杆菌液的浓度、共培养时间、外植体取材部位及时间,均可以影响发状根的诱导频率。采用添加１００μｍｏｌ／Ｌ的 乙酰丁香酮、振荡培养２４ｈ的Ａ４菌液感染３周龄的叶片切段,并共培养３ｄ,可以得到最佳的转化效果,发状根的诱导率为４８．９％。在同样的转化条件下,只有１３．６％的茎切     

Establishment of <i>Rhodiola quadrifida</i> Hairy Roots and Callus Culture to Produce Bioactive Compounds

Rhodiola quadrifida is a rare mountain medicinal plant whose root extracts are used in traditional Chinese medicine as a hemostatic, antitussive, and tonic in the treatment of gynecological diseases. The aim of the study was to obtain R. quadrifida cultures at different degrees of differentiation in vitro and compare their growth characteristics and the content of salidroside and rosavin. Hairy roots were obtained by incubating cotyledons and hypocotyls in a suspension of Agrobacterium rhizogenes strain A4. The presence of the rolB and rolC genes was proven by polymerase chain reaction. The obtained roots were cultivated in Murashige-Skoog medium (MS). Calluses were obtained from the hairy roots in MS medium with the addition of hormones: 3 mg/L 2,4 D and 0.5 mg/L BAP. The presence of the main secondary metabolites of R. quadrifida, salidroside and rosavin, in calluses and salidroside in hairy roots by HPLC/MS was confirmed. The content of salidroside in callus culture was significantly higher than in hairy roots, 0.158 and 0.047%, respectively. The content of rosavin in callus culture was 0.07%. The content of rosavin and salidroside in callus culture was close to the level of these substances in the rhizomes of R. quadrifida plants growing in vivo, making this culture promising for its possible biotechnological use.     

Establishment of Gymnema sylvestre hairy root cultures for the production of gymnemic acid

Gymnema sylvestre is an important medicinal plant that bears bioactive compound namely gymnemic acid. In the present study, G. sylvestre was transformed by Agrobacterium rhizogenes. Seedling explants namely roots, stems, hypocotyls, cotyledonary nodal segments, cotyledons and young leaves were inoculated with A. rhizogenes strain KCTC 2703. Transformed (hairy) roots were induced from cotyledons and leaf explants. Six transgenic clones of hairy roots were established and confirmed by polymerase chain reaction (PCR) and RT-PCR using rolC specific primers. Hairy roots cultured using MS liquid medium supplemented with 3 % sucrose showed highest accumulation of biomass (97.63 g l^?1 FM and 10.92 g l^?1 DM) at 25 days, whereas highest accumulation of gymnemic acid content (11.30 mg g^?1 DM) was observed at 20 days. Nearly 9.4-fold increment of biomass was evident in suspension cultures at 25 days of culture and hairy root biomass produced in suspension cultures possessed 4.7-fold higher gymnemic acid content when compared with the untransformed control roots. MS-based liquid medium was superior for the growth of hairy roots and production of gymnemic acid compared with other culture media evaluated (B5, NN and N6), with MS-based liquid medium supplemented with 3 % sucrose was optimal for secondary metabolite production. The current results showed great potentiality of hairy root cultures for the production of gymnemic acid.     

Establishment of Withania somnifera hairy root cultures for the production of withanolide A

Withanla sominifera (Indian ginseng) was transformed by Agrobacterlum rhizogenes.Explants from seedling roots,stems,hypocotyls,cotyledonary nodal segments,cotyledons and young leaves were inoculated with A.rhizogenes strain R1601.Hairy (transformed) roots were induced from cotyledons and leaf explants.The transgenic status of hairy roots was confirmed by polymerase chain reaction using nptll and roIB specific primers and,subsequently,by Southern analysis for the presence of nptll and roIB genes in the genomes of transformed roots.Four clones of hairy roots were established;these differed in their morphology.The doubling time of faster growing cultures was 8-14 d with a fivefold increase in biomass after 28 d compared with cultured,non-transformed seedling roots.MS-based liquid medium was superior for the growth of transformed roots compared with other culture media evaluated (SH,LS and N6),with MS-based medium supplemented with 40 g/L sucrose being optimal for biomass production.Cultured hairy roots synthesized withanolide A,a steroidal lactone of medicinal and therapeutic value.The concentration of withanolide A in transformed roots (157.4 μg/g dry weight) was 2.7-fold more than in non-transformed cultured roots (57.9 μg/g dry weight).     

唐古特大黄组织培养技术的研究

试验选用唐古特大黄(Rheum tunguticum Maxim．ex Regel．)种了萌发的无菌苗及无菌苗子叶、下胚轴、胚根和幼根作为材料,研究唐古特大黄不同外植体的离体培养技术。结果表明,唐古特大黄的无菌苗和无菌苗子叶、下胚轴、胚根和幼根都可以作为离体培养的良好外植体。唐古特大黄的最适分化培养基足：B5 NAA0．1mg／L 6-BA3mg／L;最适乍根培养素是：1／2MS NAA1mg／L 3%蔗糖或1／2MS NAA0．5mg／L 3％蔗糖;愈伤组织诱导培养基是：MS 2,1-D 1mg／L NAA1mg/L 6BA1mg／L。     

大花金挖耳愈伤组织诱导与增殖

以大花金挖耳无菌苗的子叶、下胚轴和根为外植体,进行愈伤组织诱导与增殖研究。结果表明:大花金挖耳无菌苗的根是诱导愈伤组织的理想外植体;其愈伤组织诱导的最适培养基为:B5 3.0mg/L NAA 0.2mg/L6-BA,诱导率可达100%;愈伤组织的增殖在45g/L的蔗糖、pH5.7、光照12h/d培养条件下可延迟愈伤组织褐化出现的时间,并维持其良好的组织结构,愈伤组织的最适继代周期为30~40d。     

Formation of embryogenic callus in hairy roots of pumpkin (<Emphasis Type="Italic">Cucurbita pepo</Emphasis> L.)

Summary Excised cotyledons from 8-d-old pumpkin (Cucurbita pepo L.) seedlings were inoculated with Agrobacterium rhizogenes and cultured on hormone-free Murashige and Skoog medium. At the site of inoculation, transformed hairy roots were successfully induced by using wild strains 8196 (mannopine-type) and 15834 (agropine-type). After a subsequent transfer on a solid MS medium without hormones, roots obtained by transformation with strain 15834 failed to form stable hairy root cultures, while several hairy root lines were established with strain 8196. Three hairy root lines, Cp1, Cp2, and Cp31, have spontaneously generated callus with embryo-like structures after more than 3 yr of growth on the solid medium. The callus proliferation was more frequent when the autoclaving of nutrient medium, pH 5.7, was prolonged to 30 min. Separated calluses continued to proliferate and generated embryos with abnormal morphology. The combination of indole-3-acetic acid and benzyladenine had a favorable influence on embryogenesis and organogenesis in the Cp31 callus line. The Southern analysis of Cp31 root and embryo DNA confirmed the presence of the T-DNA of Agrobacterium rhizogenes.