白桦的遗传转化及转基因植株的抗虫性

应用农杆菌介导法首次向白桦(Betula platyphylla Suk.)基因组中导入抗虫基因[蜘蛛杀虫肽与苏云金杆菌杀虫毒蛋白基因(Bt基因)C肽序列的嵌合基因].转化结果表明:共培养2 d的脱菌及防止腐烂的效果和转化率均高,液体共培养及液体除菌优于固体共培养及固体除菌;最佳外植体为大叶片;侵染2个月之后产生抗性愈伤组织,转化率达到22%.卡那霉素抗性植株中,GUS阳性率为43%.进行杀虫肽和nptⅡ基因的PCR(聚合酶链式反应)均检测出目的带.转化植株目的基因的PCR Southern(DNA印记杂交)杂交呈阳性,证明获得了转基因植株.初步的喂虫试验表明转基因白桦具有一定的抗虫性.     

农杆菌介导韭菜遗传转化相关因素的研究

以"汉中冬韭"韭菜品种为试验材料,用含有pCAMBIA3301质粒的根癌农杆菌菌株EHA105对影响韭菜遗传转化效率的多种因素进行研究。结果表明,诱导40 d的愈伤组织,GUS基因瞬时表达率达到93%,且最适宜于不定芽的分化;当乙酰丁香酮(AS)的浓度为100μmol/L时,愈伤的GUS表达率达到91%,植株再生率为7.9%,AS浓度增加时其值也不会增加;菌液OD600值为0.6侵染10 min时,与其他组合相比,外植体受伤程度小,GUS表达率及再生率最高;侵染后的愈伤共培养3 d后,农杆菌生长较少,GUS表达率为91.1%,而再生率达到7.2%,为最佳的共培养时间。通过试验得到韭菜遗传转化因素的最佳条件,为今后的遗传转化提供一些参考。     

红树林耐盐相关基因转化水稻的研究

运用农杆菌介导法将红树林耐盐相关基因mangrin转入粳稻品种‘日本晴’中,通过GUS基因检测愈伤组织转化率,确定农杆菌菌液浓度OD600为0.5,浸染时间30min,共培养时间3d为最佳转化体系;经潮霉菌筛选,获得抗性再生植株。通过PCR扩增检测、Southern blot分析和GUS基因活性检测,结果表明,mangrin基因整合到再生水稻的染色体DNA上。耐盐性测定结果表明,转基因植株在200mmol/L NaCl胁迫下,成活率保持在83.3%,株高增长20%~40%,mangrin基因能提高转基因水稻对盐胁迫的抗性。     

农杆菌介导的蓖麻转化体系优化

针对影响农杆菌侵染效率的主要因素进行条件优化,确立了以OD600为0.8的菌液侵染、预培养5 d后的外植体为最佳侵染条件;侵染外植体经过5 d的共培养并除菌后,转到含有250 mg/L Kan的培养基中进行再生诱导,获得了多株具有Kan抗性的再生植株;通过在共培培养基中添加20 mg/L AS,124 mg/L Na2S2O3和152.4 mg/L DTT,有效地抑制了侵染后外植体的褐化现象,提高了筛选阶段抗性芽的成活率;对具有Kan抗性的再生植株进行PCR和Southern blot验证,共获得18株包含外源基因的阳性转化株。     

高羊茅和黑麦草农杆菌介导转化体系的研究

利用C58C1农杆菌菌系（携带的表达载体上含GUS基因和nptII基因）感染4个草坪草品种追寻者、爱神特、腾跃和守门员成熟胚来源的愈伤组织,共培养后部分愈伤组织进行X-Gluc组织化学染色检测,其余愈伤组织在含G418 10-25 mg/L的MS改良培养上先后筛选抗性愈伤组织和分化抗性再生植株,对移栽成活的144棵抗性再生植株分别进行了ELISA检测、PCR检测和组织化学染色检测。愈伤组织阶段X-Gluc染色检测结果表明,4个草坪草品种GUS基因瞬间表达率8.6%～46.9%,爱神特愈伤组织对农杆菌侵染最为敏感,其次是腾跃和守门员,追寻者最不敏感;ELISA检测结果表明,45株呈现阳性,证明nptII基因已转入草坪草并已表达;PCR检测结果与ELISA检测结果一致,表明nptII基因确实已经整合到了草坪草基因组中,且没有发生沉默现象;转基因植株X-Gluc染色检测结果表明,GUS基因在43株中得到了稳定表达,在2株中发生了沉默现象。4个草坪草品种抗性再生植株分化率0～43.5%,转化率0～21.5 %。结果还表明,GUS基因瞬间表达率与稳定转化率在草坪草上很不一致,不能作为衡量基因型转化效果的指标。     

简单高效的根癌农杆菌介导的水稻基因转化方法

本文在研究影响农杆菌介导的水稻转化的主要因素基础上,建立了一套简单、高效的水稻转基因系统。将水稻成熟胚来源的愈伤组织用农杆菌EHA101/pHQ9,EHA 101/pHQ 10,EHA 101/pHQ T3感染后,筛选抗性愈伤,经分化获得转化株。抗性愈伤的平均得率为约100个愈伤/g愈伤外植体,抗性愈伤的分化频率平均高达85%。转基因植株的GUS染色、Southern杂交结果表明,T-DNA上的外源基因已整合进转基因植物的基因组中。转基因植株T1代对潮霉素的抗性表明,多数转基因株系符合孟德尔分离比3∶1。该系统的建立将有助于应用T-DNA标签法和基因打靶法进行水稻功能基因组的研究。     

EuFPS基因表达载体构建及对杜仲遗传转化的研究

本实验用EcoRⅠ和BamHⅠ双酶切植物表达载体pSH737和含有目的基因的pUC-FPS,定向连接得到重组质粒pSH-FPS,将其导入农杆菌EHA105.采用农杆菌介导法对杜仲进行遗传转化,研究了卡那霉素(kanamycin,Km)浓度、预培养时间、菌液浓度及侵染时间、乙酰丁香酮(acetosyringone,AS)浓度、共培养时间等对杜仲遗传转化效率的影响.结果表明,选择无菌苗苗龄15 d的杜仲下胚轴,卡那霉素浓度50mg/L,农杆菌浓度OD600值0.3-0.6,侵染时间8 min,侵染时菌体重悬液中添加50 μmol/L乙酰丁香酮,共培养时间3 d,抗性芽的获得率最高.对再生植株进行GUS检测发现有45%的植株呈阳性.     

农杆菌介导巨桉Eg5高效遗传转化

以巨桉(Eucalyptus grandis)无性系Eg5叶片为外植体, 探讨了农杆菌(Agrobacterium tumefaciens)侵染时间、共培养pH值和共培养时间对瞬时转化效率的影响, 分析了不同筛选策略对遗传转化植株筛选效果的影响。结果表明, 外植体侵染45分钟, 共培养pH值为5.8, 共培养3天所得到的瞬时转化效率最高; 逐步提高卡那霉素(Km)浓度筛选转基因植株有效, 筛选率达到15%, 转化率达到0.26%。经过GUS染色分析和PCR检测, 证实为转基因植株。     

简单高效的根癌农杆菌介导的水稻基因转化方法

本文在研究影响农杆菌介导的水稻转化的主要因素基础上,建立了一套简单、高效的水稻转基因系统。将水稻成熟胚来源的愈伤组织用农杆菌EHA101／pHQ9,EHA101／pHQ10,EHA101／pHQT3感染后,筛选抗性愈伤,经分化获得转化株。抗性愈伤的平均得率为约100个愈伤／g愈伤外植体,抗性愈伤的分化频率平均高达85％。转基因植株的GUS染色、Southern杂交结果表明,T-DNA上的外源基因已整合进转基因植物的基因组中。转基因植株T1代对潮霉素的抗性表明,多数转基因株系符合孟德尔分离比3：1。该系统的建立将有助于应用T—DNA标签法和基因打靶法进行水稻功能基因组的研究。     

影响农杆菌介导的大豆子叶节遗传转化的因素

利用携带pCAMBIA1301质粒（含hpt和gus基因）的超毒根癌农杆菌菌株EHA105对大豆子叶节外植体进行遗传转化,研究了影响农杆菌介导的大豆子叶节遗传转化的因素。研究结果表明．农杆菌侵染液和共培养培养基中添加200μmok/L乙酰丁香酮和50mg／L抗坏血酸可以有效促进农杆菌对大豆子叶节的转化。农杆菌与子叶节共培养后羧苄青霉素（250mr／L）和头孢霉素（100mg／L）结合使用能有效抑制农杆菌过度繁殖并提高转化芽诱导频率;在转化细胞的分化和转化芽伸长过程中,改进的筛选策略可以明显改善对转化芽的筛选效果,从而提高转化频率。应用优化后的转化体系．获得了3个国内大豆主栽品种的转基因植株,PCR阳性植株频率为3．8％～7．6％。转化植株叶片总DNA的PCR和Southern blot实验表明,T-DNA上的外源基因已经整合到大豆基因组中。     

影响农杆菌介导白细胞介素-2基因转化番茄的因素研究

利用农杆菌介导法将白细胞介素-2基因（il-2）导入番茄中,对影响其转化的因素进行了分析。结果表明：农杆菌菌种（EHA105和C58C1）、外植体类型（子叶和下胚轴）、带有不同筛选标记（Kan^r、PPT^r、Hyg^r）的载体质粒几个因素对芽诱导分化及转化均有影响。实验共接种转化2018个子叶和下胚轴外植体,获得了47株抗性再生株,对其进行il-2的PCR扩增检测,有44株呈阳性。PCR-Southern杂交证实PCR结果可靠,显示il-2基因已导入到番茄中。     

影响农杆菌介导的木薯基因转化因素的研究

Factors influencing agrobacterium-mediated cassava transformation were investigated. Among the four Agrobacterium strains tested, LBA 4404 (pTOK 233) and LBA 4404 (pBin9GusInt) gave higher transient expression than C 58 C1 (pIG121Hm) and EHA 105 (pBin9Husint). Pretreatment of explants by bombardment or vaccum had no significant effect on transient expression while preinduction of Agrobacterium with acetosyringone showed better effects, and preculture of explants showed worse effects. All the cultivars tested were susceptible to Agrobacterium infection, while the types of explants and the physiological state of the explants had a strong influence on the transient expression efficiency. The 15-day-old somatic cotyledons and the fully expanded leaves from in vitro plantlets were the most susceptible to Agrobacterium infection. The results also showed that all the four selective reagents (hygromycin, geneticin, PPT, and kanamycin) synchronously suppressed the growth of callus, shoot organogenesis and shoot rooting in a dose dependent manner.     

Study of the factors influencing Agrobacterium-mediated transformation of pea (Pisum sativum L.)

Factors influencing the efficiency of Agrobacterium-mediated transformation of pea were tested using highly efficient, direct regeneration system. The virulence of three Agrobacterium strains (octopine LBA 4404, nopaline C58C1 and succinamopine, hypervirulent EHA 105) clearly varied giving 1 transgenic plant per 100 explants for LBA 4404, 2.2 for C58C1 and 8.2 for EHA 105. To test the efficacy of selection agents we used the hypervirulent EHA 105 strain carrying pGPTV binary vector with one of four different selection genes: nptII, hpt, dhfr or bar. The mean number of transgenic, kanamycin-resistant plants for two cultivars tested was 4.2 per 100 explants and was slightly higher than the number of phosphinothricin-resistant plants (3.6 plants per 100 explants). The proportion of transgenics among kanamycin-selected plants was also higher than among phosphinothricin-resistant plants (35% and 28% respectively). There was no regeneration on hygromycin or methotrexate media (transformation with hpt and dhfr genes). Acetosyringone had no apparent influence on efficiency of transformation with hypervirulent EHA 105 strain, however it did affect the rate of transformation when moderately virulent C58C1 was used. Recovery of transgenic plants was enhanced after application of 5-azacytidine. The presence of integrated T-DNA was checked by PCR and confirmed by Southern hybridization. T-DNA was stably transmitted to the next generation.     

基于高遗传转化率及低幼苗玻璃化率的黑果枸杞叶片组合培养体系

【目的】建立高效稳定的黑果枸杞遗传转化体系,有效降低其再生幼苗玻璃化率,促进其基因功能研究和提高遗传改良效率。【方法】以黑果枸杞叶片作为外植体,利用农杆菌(LBA4404、EHA105)介导的遗传转化法,通过调整基础培养基类型并添加相应浓度的植物激素,筛选出最适愈伤组织诱导培养基、分化和选择培养基、生根诱导培养基,将黑果枸杞遗传转化率提高到65%以上,同时降低幼苗玻璃化率至10%以下。【结果】(1)黑果枸杞叶片高效组合培养体系中最佳农杆菌侵染浓度(OD₆₀₀)为0.6,侵染时间为25 min,在此条件下侵染叶片抗性愈伤诱导率达78.2%～96%;(2)黑果枸杞遗传转化中最适分化和选择培养基为：MS+肌醇50 mg/L+烟酸0.25 mg/L+维生素B₆ 0.25 mg/L+铁盐母液1 mL/L+甘氨酸1.0 mg/L+维生素B₁ 0.05 mg/L+6-BA 0.25 mg/L+蔗糖30 g/L+琼脂6 g/L+卡那霉素30 mg/L+特美汀300 mg/L (pH=6.0);最适生根诱导培养基为：WPM+IBA 0.2...     

影响农杆菌介导的木薯基因转化因素的研究

本文研究了影响农杆菌介导的木薯基因转化的因素。结果表明,供试的4个菌种中,LBA4404(pBin9GusInt)及LBA4404(pTOK)瞬时表达效果较好。对农杆菌的诱导处理能增强瞬时表达效果,外植体的预处理对瞬时表达无影响,而外植体的预培养显著降低瞬时表达。所有供试的木薯品种都能被农杆菌侵染,但外植体的类型及生理状况对农杆菌的侵染力影响很大,成熟胚状体的子叶(萌发15d)及试管苗完全展开的叶片对农杆菌亲和性最高。四种筛选剂(kanamycin、hygromycin、phosphinothricin及geneticin)均表现出剂量效应且能同步抑制芽器官发生、愈伤生长及芽切段生根。     

马铃薯遗传转化体系的优化建立及其主要影响因素

植物基因转化的成功依赖于一个良好的转化系统,能有效地将外源基因导入受体细胞,并得以表达。通过农杆菌介导的马铃薯遗传转化体系主要受基因型、预培养、菌液浓度及侵染时间、共培养等因素的影响,由于转化受体的异质性,有必要根据实际情况进行验证和改进,以获得最适转化条件。本研究以马铃薯无菌苗的叶片、茎段为外植体,通过农杆菌介导法,将抗马铃薯X病毒和Y病毒的RNA干扰型基因结构转入马铃薯。通过研究外植体预培养、菌液浓度及侵染时间、共培养等不同转化条件及影响因素对马铃薯遗传转化的影响,建立一种高效的马铃薯遗传转化体系,试验得出最佳转化条件为外植体预培养2 d,然后用OD600=0.5的农杆菌液侵染10 min,共培养2 d。本研究为下一步的对PVX和PVY双抗的马铃薯无标记转基因研究提供技术参考。     

转TaDREB基因提高芦荟抗低温特性的研究

以库拉索芦荟(Aloe vera L.)幼茎为外植体,利用农杆菌介导法将携带小麦功能基因TaDREB的表达载体pBIR1转化库拉索芦荟,在添加3.0mg/L BA、250mg/L Carbenicillin和15~25mg/L G418的MS培养基上诱导、筛选丛生芽,连续筛选几代后,将2.0~3.0cm高的抗性再生芽转移到1/2MS生根培养基上壮苗,共获得58株生长良好的抗性植株。根据标记基因npt Ⅱ及目的基因TaDREB的序列设计上游引物,对所有抗性植株进行PCR检测,共获得3株PCR阳性植株,结果表明目的基因的转化效率为0.5%。将转基因阳性植株置于4℃低温处理2周,20℃冷冻处理30min,发现对照植株发生严重冻害,而转基因植株生长良好,抗低温特性明显提高。对低温胁迫条件下培养14天的转基因植株SOD、POD酶活性进行分析,结果表明低温胁迫下转基因植株SOD、POD活性均呈降－升－升－升趋势变化,与非转基因植株的变化趋势降－升－降－降有所不同。进一步利用电导率法检测,结果转基因植株电导率的平均值为0.456,明显低于对照的0.685;说明转基因芦荟细胞膜的稳定性得到很好的改善,是其抗低温特性提高的内在生理基础。     

Agrobacterium-mediated transformation of African violet

A method for genetic transformation of Saintpaulia ionantha by co-cultivation of in vitro-grown leaves and petioles with Agrobacterium tumefaciens is described. Two bacterial strains, EHA105 and A281 both harbouring the binary plasmid pKIWI105 carrying the genes uidA and nptII, were used in the experiments. Regenerants were not obtained using the disarmed strain EHA105. The oncogenic strain A281 resulted in efficient transient and stable expression of the transferred traits for petiole explants only. After transformation and regeneration, the integration of the transgenes in the plant genome was confirmed by PCR analysis and Southern hybridization.     

农杆菌介导的小麦遗传转化几个影响因素的研究

采用携带gus和（或）bar基因双元表达载体（p3301,pBTAaB)的3个根癌农杆菌（Agrobacterium tumefaciens)菌株（AGL-1,EHA105和LBA4404）对普通小麦（Triticum aestivumL.)冬性栽培品种农大170和农大146的幼胚及幼胚愈伤组织进行了遗传转化,结果表明,菌液浓度OD6001.0和侵染时间1h对外植体的生存和转化最为有利;侵染前对外植体进行高渗处理较明显地提高了抗性愈伤获得率;乙酰丁香酮（AS）对小麦转化的作用随菌株和外植体的不同而异;菌株/质粒组合,受体基因型及外植体的类型,年龄和生理状态对转化效率有很大的影响,条件优化后,得到大量具有PPT抗性的愈伤和一些抗性植株,抗性愈伤的GUS染色阳性率在50%-60%之间,所检测的抗性苗呈GUS阳性,对6株抗性苗的PCR和Southern检测初步证明,外源基因已经整合到其中3株的基因组中。     

Transgenic Medicago truncatula plants obtained from Agrobacterium tumefaciens -transformed roots and Agrobacterium rhizogenes-transformed hairy roots

Medicago truncatula, barrel medic, is a forage crop that has been developed into a model legume. The development of new transformation methods is important for functional genomic studies in this species. Based on Agrobacterium tumefaciens-mediated transformation of root explants, we developed an effective system for producing M. truncatula (genotype R108) transgenic plants. Among the four A. tumefaciens strains (AGL1, C58C1, EHA105 and LBA4404) tested, EHA105 and AGL1 were most effective in regenerating transgenics. Callus induction frequency from root explants was 69.8%, and plantlet/shoot regeneration frequency was 41.3% when EHA105 was used. Transgenic nature of the regenerated plants was confirmed by PCR and Southern hybridization analyses. Progeny analysis revealed stable Mendelian meiotic transmission of transgenes. Because M. truncatula is particularly useful for the study of root endosymbiotic associations, we further developed a plant regeneration system from A. rhizogenes-transformed hairy roots of M. truncatula. Fertile true transgenic plants were regenerated from the hairy roots, thus allowing the assessment of gene functions at the whole plant level. Segregation analysis revealed that the hairy root genes could be segregated out in the progenies. By coupling A. rhizogenes-mediated hairy root transformation and the regeneration system reported here, once potential genes of interest are identified, the transformed hairy roots carrying such genes could be directly regenerated into plants for more detailed characterization of the genes.