抗生素对农杆菌的抑制和对油菜外植体分化的影响

通过哌拉青霉素、氨苄青霉素、青霉素钠、羧苄青霉素、头孢拉定、头孢唑啉钠、磷霉素钠、乳糖酸红霉素、白霉素9种抗生素对根癌农杆菌EHA105和LBA4404的抑制效果,以及对油菜子叶柄分化影响的研究,结果表明：羧苄青霉素在500mg／L时对农杆菌EHA105的抑菌效果最好,而其它8种抗生素对EHA105无明显的抑菌作用;对于LBA4404浓度为200mg／L的羧苄青霉素、氨苄青霉素和头孢唑啉钠都有良好的抑菌效果。不同抗生素对油菜子叶柄的分化试验结果表明,羧苄青霉素和头孢唑啉钠对离体油菜子叶柄再生分化及生长没有影响,磷霉素钠、乳糖酸红霉素、自霉素几乎完全抑制了油菜子叶柄分化。同时对卡那霉素(作为筛选剂)的浓度进行了筛选,确定了油菜33B的筛选浓度为15mg／L,油菜918B的筛选浓度为10mg／L。     

不同抗生素对雪莲愈伤组织生长的影响

以雪莲叶片为外植体,探讨了卡那霉素(kanamycin,Kan)、潮霉素(hygromycin B,Hyg)、羧苄青霉素(car-benidillin,Car)3种抗生素对雪莲愈伤组织诱导、生长及分化的影响,以确定农杆菌介导的遗传转化研究中筛选剂和抑菌剂的最适浓度。结果表明:40mg/L的卡那霉素已抑制雪莲愈伤组织生长,当卡那霉素为50mg/L时,愈伤组织的生长基本停止;8.0mg/L潮霉素能够有效抑制雪莲愈伤组织的生长,当潮霉素为20mg/L时则生长的愈伤组织块较小、褐化、甚至死亡。同时,低浓度(0.5～2.0mg/L)的潮霉素可以提高雪莲愈伤组织的分化率;作为农杆菌抑菌剂,不同浓度羧苄青霉素对雪莲愈伤组织生长的影响差异极显著,当羧苄青霉素的浓度超过400mg/L时对雪莲愈伤组织的出愈及生长均有明显的抑制作用。     

胡杨遗传转化体系的建立及抗生素浓度的优化

探讨了不同激素浓度对胡杨叶片分化以及卡那霉素、G418、羧苄青霉素和头孢霉素4种抗生素对胡杨不同培养阶段外植体生长、分化或生根的影响,确定了由农杆菌介导的胡杨遗传转化研究中抗生素种类和转化体的筛选浓度,建立了适于胡杨叶片转化的遗传转化体系。结果表明:胡杨叶片再生的最佳培养基为MS+BA0.5mg/L+NAA0.1～0.2mg/L+白砂糖25g/L+琼脂5g/L;在叶片转化筛选阶段,卡那霉素和G418的适宜浓度分别为10mg/L和7.5mg/L,羧苄青霉素和头孢霉素的适宜浓度为200～600mg/L和200～400mg/L;在抗性芽生根培养时,卡那霉素和G418分别为15～20mg/L和10～15mg/L,羧苄青霉素和头孢霉素为200～800mg/L和200～600mg/L。     

中国传统菊花品种‘小林静’再生及转化体系的建立

以中国传统菊花品种‘小林静’叶片为外植体,建立了‘小林静’较好的再生体系及遗传转化体系.结果表明,‘小林静’叶盘最适不定芽分化培养基为MS+2.0 mg/L 6-BA+1.5 mg/L NAA,不定芽分化率为92.76％,平均再生不定芽数为2.3767个;试管苗最佳生根培养基为1/2MS,生根率达100％.移栽采用灭菌的蛭石,再生苗移栽成活率达90％以上.采用根癌农杆菌C58C1介导的叶盘转化法进行‘小林静’的遗传转化试验,农杆菌OD600=0.5-0.6,侵染10 min后,将叶片外植体接种到MS+2.0 mg/L 6-BA+1.5mg/L NAA的培养基中黑暗共培养2d,之后转接到附加10 mg/L硫酸卡那霉素和400 mg/L羧苄青霉素的分化筛选培养基中进行转化细胞的筛选,待长出抗性芽后转接至生根培养基中进行培养,最终建立了菊花品种‘小林静’的遗传转化体系.     

带内含子卡那霉素抗性基因双元载体构建及烟草转化

农杆菌介导法是植物基因转化的常用方法,然而由于筛选培养基中常用的抗生素头孢霉素和羧苄青霉素具有类植物激素活性,影响外植体的再生和转化频率,将一个植物的内含子插入卡那霉素抗性基因编码区的N端。合成了一个带内含子的卡那霉素抗性基因。构建带该基因的植物双元表达载体pYP1202并转化烟草,受外植体在含卡那霉素50－200mg/L的选择培养基中抗性芽分化频率不受卡那霉素浓度影响,然而具有GUS活性的转化子占分化芽的比例却随着卡那霉素浓度的增加而升高。当培养基中加入500mg/L羧苄青霉素后受侵外植体产生的抗性芽频率比单一的卡那霉素筛选提高近1倍,高达91.4％,然而具GUS活性的转化子占抗性芽的比较仅有26.7％,在200mg/L的卡那霉素筛选下,比例升至93.3％。用带内含子卡那霉素抗性基因构建的植物表达载体转化植物可以减少假抗性芽的产生。     

带内含子卡那霉素抗性基因双元载体构建及烟草转化

农杆菌介导法是植物基因转化的常用方法,然而由于筛选培养基中常用的抗生素头孢霉素和羧苄青霉素具有类植物激素活性,影响外植体的再生和转化频率。将一个植物的内含子插入卡那霉素抗性基因编码区的N端,合成了一个带内含子的卡那霉素抗性基因。构建带该基因的植物双元表达栽体pYP1202并转化烟草,受侵外植体在含卡那霉素50～200mg/L的选择培养基中抗性芽分化频率不受卡那霉素浓度影响,然而具有GUS活性的转化子占分化芽的比例却随着卡那霉素浓度的增加而升高。当培养基中加入500mg/L羧苄青霉素后受侵外植体产生的抗性芽频率比单一的卡那霉素筛选提高近1倍,高达91.4％,然而具GUS活性的转化子占抗性芽的比例仅有26.7％,在200m/L的卡那霉素筛选下,比例升至93.3％。用带内含子卡那霉素抗性基因构建的植物表达载体转化植物可以减少假抗性芽的产生。     

农杆菌介导的橡胶草遗传转化体系的建立

以橡胶草为试验材料,利用农杆菌介导法进行遗传转化研究。结果表明：50 mg/L的卡那霉素(Kan)对橡胶草的抗性芽具有很好地筛选效果,生根筛选时,Kan的适宜质量浓度为35 mg/L;最佳抑菌抗生素为羧苄青霉素（cb）,适宜质量浓度为500 mg/L,获得35株抗性试管苗,通过GUS染色及分子生物学检测,最终获得6株转基因植株,转化率为17.1%。可见,获得的橡胶草转基因植株,为橡胶草后续的遗传转化研究奠定了基础。     

农杆菌介导的紫花苜蓿高效遗传转化体系的研究

为建立高效的农杆菌介导的紫花苜蓿的遗传转化体系,对影响转化体系的若干因素进行了研究.结果表明,最适宜的条件分别为抗菌素为350 mg/L的羧苄青霉素(Carb);卡那霉素(Kan)筛选的浓度为60 mg/L;基因型为WL-323;外植体为下胚轴;农杆菌菌液浓度OD600值为0.4-0.6;侵染时间10 min;乙酰丁香酮(AS)的浓度为10 mg/L.     

根癌农杆菌介导D32基因

以烟草品种'中烟99'的无菌苗叶片为转化受体材料,通过根癌农杆菌C58C1介导对大豆中克隆的抗逆性基因D32进行转化,获得了抗卡那霉素的再生植株,并对转化植株进行了PCR检测.结果表明,烟草叶片分化和再生的卡那霉素选择压力为150 mg/L;外植体预培养对转化率有影响;优化的烟草转化方法是:经预培养2 d的外植体用OD600值为0.7的菌液侵染5 min, 共培养2 d后用无菌水冲洗5～6次,羧苄青霉素(Cb)和头孢霉素(Cef)浓度为400 mg/L的脱菌液浸泡120 min,超净工作台上吹风60 min,于筛选分化培养基生长50 d,可获得26.7%卡那抗性苗.对抗性植株经PCR检测证明,外源D32基因已初步整合到烟草基因组中.     

发根农杆菌诱导甘薯发根条件的优化

通过诱导甘薯(徐薯18)发根的条件进行优化,分别时侵染时间(10min、20min和30min)、培养基[MS、MSJ(MS BA0.1mg/L NAA0.2mg/L)和MSS(MS BA0.2mg/L NAA0.1mg/L)]、诱导材料(叶片、叶柄和茎切段)和除菌药物剂量(羧苄青霉素浓度0.5mg/L、1.0mg/L和1.5mg/L)进行优化.试验按L9(34)正交设计,每个处理3次重复.然后通过PCR检测徐薯18和其发根中的rol基因.结果表明用发根农杆菌A4经20min侵染,通过MSJ活化的徐薯18的茎切段生成发根的发根诱导率最高,最佳的除菌羧苄青霉素浓度为1.0mg/L.PCR检测证明得到的发根是发根农杆菌诱导产生的.在此优化条件下诱导的发根诱导率高,得到发根的可靠性强,且生成的发根粗壮、生长迅速、分支众多.     

抗生素对大豆愈伤组织的诱导和生长的影响

用红霉素、头孢唑唑钠、头孢拉定、头孢霉素（国产和进口）等5种抗生素对农杆菌LBA4404进行抑菌试验,以头孢霉素的抑菌效果最好。头孢霉素作为抑菌剂用大于豆遗传转化试验时,在下胚轴浓度以300mg/L,在子叶节以500mg/L。大豆品种对卡那霉素的反应在出愈率上表现相似,在褐化率上表现有些不同。大豆不同外植体对卡那霉素的反应存在较大差异,以真叶反应最敏感,下胚轴反应最迟钝。在以卡那霉素作为抗性选择标记时,选择压力真叶和子叶节以50－100mg/L为好,下胚轴以100－200mg/L为宜。     

'早红'草莓高效遗传转化受体系统的建立

本文以草莓主栽品种'早红'组培苗离体叶片和叶柄为外植体,进行叶龄、暗培养、植物生长调节剂配比及抗生素敏感性研究,建立草莓高效遗传转化的受体系统.在含3.0 mg/L 6-BA与0.1 mg/L 2,4-D的MS培养基上,30 d叶龄的叶片再生频率高达98.31%,平均每叶片再生芽数5.09个,叶柄切段的再生频率为89.25%,平均每叶柄切段再生芽数4.92个,叶片的再生频率略高于叶柄;不定芽在含0.2 mg/L 6-BA与0.2 mg/L GA_3的MS继代培养基上培养成苗.将生长状态良好的不定芽转至含0.2 mg/L IBA的1/2 MS培养基上生根,生根率达100%,平均生根数量16.27条,平均根长1.85 cm.抗生素敏感性试验表明,草莓外植体适宜的卡那霉素选择压力为25 mg/L,头孢霉素的筛选浓度为300mg/L.本研究建立的再生体系可作为草莓遗传转化的受体系统.     

农杆菌介导南瓜遗传转化体系的建立

以南瓜金辉一号（Cucurbita moschata＇ Jinhui1＇）为实验材料,利用根癌农杆菌（Agrobacterium tumefaciens）介导转化南瓜子叶节,研究了预培养时间、侵染时间、乙酰丁香酮（AS）浓度和共培养时间,抗生素羧苄青霉素（Carb）、头孢霉素（Cef）以及筛选剂卡那霉素（Kan）等因素对离体不定芽的影响,建立了南瓜最适遗传转化体系。结果表明：外植体预培养0天,侵染时间30分钟,AS浓度为100mg·L^-1,共培养5天可获得最高遗传转化效率;最适除菌剂为Cef,其最适浓度为500mg·L^-1;最适Kan筛选浓度为100mg·L^-1;在MS培养基上培养抗性芽生根,经PCR和Southern blot检测,证明为转基因植株。     

Kanamycin sensitivity of cultured tissues of Vitis

Summary The kanamycin sensitivity of callus growth and adventitious shoot and root formation was studied in several cultivars of Vitis vinifera L. and in V. rupestris Scheele cv. St. George to investigate the suitability of kanamycin resistance as a selectable marker for grape transformation. Kanamycin concentrations ranged from 0 to 30 mg/l. Carbenicillin was added to the medium in all experiments at concentrations of 500 or 250 mg/l, as normally used in cocultivation experiments with Agrobacterium. Callus formation, root initiation, and adventitious shoot formation were completely inhibited by 20, 10, and 7 mg/l kanamycin, respectively; suggesting that these are the minimum concentrations that should be necessary to select transformed plants. Carbenicillin produced inhibitory effects that sometimes resembled those of growth regulators. The high kanamycin sensitivity of adventitious shoot formation in grape exceeds that reported for any other plant species and is likely to hinder the recovery of transformed plants.     

The toxicity of antibiotics and herbicides on in vitro adventitious shoot formation of Pinus pinea L. cotyledons

Summary The toxicity of three antibiotics commonly used to eliminate Agrobacterium tumefaciens from plant tissue during transformation were tested to determine their effect on Pinus pinea L. morphogenesis. Cefotaxime and vancomycin at a dose of 250 μg ml⁻¹, as well as ticarcillin at 300 μg ml⁻¹, were essentially nontoxic to the culture and significantly enhanced regeneration and shoot development. Kanamycin, a widely used selection agent for plant transformation, strongly inhibited regeneration even at very low doses. On the contrary, phosphinothricin and its ammonium salt glufosinate in the commercial formulation Finale? proved to be the best selection agents because they were less toxic to stone pine cotyledons. Thus, they could be applied immediately after transformation to avoid escapes. Other schemes for selection and recovery of transgenic stone pine trees are discussed.     

Micropropagation of thirteen Malus cultivars and rootstocks,and effect of antibiotics on proliferation

Several factors that affect in vitro establishment, proliferation, and rooting of thirteen Malus cultivars and rootstocks were studied. Apple shoot tips (1.5±0.5 cm in length) were established using ascorbic and citric acids as antioxidants. Four proliferation media containing 1.0 mg 1^–1 BA and different concentrations of IBA and GA₃ were tested. Proliferation rates varied depending on the genotype and medium used. The highest proliferation rate was obtained for a rootstock that produced 11.6±2.5 shoots (1.5±0.8 cm in length) per tube per month. Rooting was induced with IBA for all the genotypes tested. The optimal IBA concentration was cultivar dependent (between 0.1 and 1.0 mg 1^–1 IBA), and lower concentrations were necessary to induce rooting in liquid rather than in solid medium.The effects on shoot-tip proliferation of cefotaxime, carbenicillin and kanamycin, three antibiotics commonly used for transformation studies, were also evaluated. Cefotaxime at 200 mg 1^–1 stimulated shoot growth and development, but at 500 mg 1^–1 caused abnormal shoot morphology. Carbenicillin at 500 mg 1^–1, alone or in combination with cefotaxime at 200 mg 1^–1, inhibited proliferation and caused excessive enlargement of the basal leaves, inducing callus formation and release of phenolic compounds in the medium. Kanamycin at 50 mg 1^–1 was phytotoxic and caused shoot chlorosis and necrosis. Consideration of the toxicity of these antibiotics is critical when designing transformation schemes for selection and recovery of transgenic apple plants.Abbreviations BA benzyladenine - cef cefotaxime - crb carbenicillin - GA₃ gibberellic acid - IBA indole-3-butyric acid - Kan kanamycin - ms Murashige and Skoog [19] macro- and micro-nutrients - NAA naphthalene-acetic acid     

番茄ACC合酶反义基因对河套蜜瓜的转化

河套蜜瓜（CucumismeloLcvHetau）的子叶经预培养。芽诱导和生根培养,获得再生小植株,诱导率达58％。取带有番茄ACC合酶反义基因的双元载体pMQ6／JM109与农杆菌（Agrobacteriumtumefaciens）LBA4404经三亲融合后,与在MS0上萌发5d、并在MS＋1mg／LNAA培养基上预培养3d的子叶共培养48h,然后转入含50mg／L卡那霉素的MS＋6mg／LZT的芽诱导培养基中,1l个月后诱导生芽,待芽长1．5－2cm时转入生根培养基中,1－2周后可诱导产生大量的根,形成完整的转基因小植株。经PCR和分子杂交检测证明,目的基因已整合入河套蜜瓜的基因组中。     

Transformation of Cucumis melo cv. Hetau with Tomato Antisense ACC Synthase Gene

An efficient in vitro plant regeneration system of Cucumis melo L. cv. Hetau was established. Regenerated plantlets were obtained from cotyledons after preculture, shoot inducing culture and root inducing culture. A high regeneration rate was achieved up to 58%. Cucumis melo was transformed with the antisense tomato ACC synthase gene in binary vector pMQ6 via Agrobacterium tumefaciens mediated gene transfer. Kanamycin resistant plantlets were obtained on MS medium with 6 mg/L zeatin, 50 mg/L kanamycin and 650 mg/L cefotaximine. PCR and molecular hybridization analysis showed that tomato ACC synthase antisense cDNA was integreted into the genome of C. melo.