发根农杆菌介导的白花草木樨毛状根转化体系的建立

白花草木樨（Melilotus albus Medic.ex Desr.）是草木樨最常见的栽培用种之一，具有较强的抗逆性和固氮能力。为了开发一套高效的草木樨转化体系，本研究以白花草木樨为材料，以结瘤基因MaROP6为目的基因，建立了发根农杆菌（Agrobacterium rhizogenes）介导的高效白花草木樨毛状根转化体系。结果表明：利用该方法可以在两周左右获得毛状根，其发生率可达78%，MaROP6基因的毛状根转化率可达70.8%。qRT-PCR鉴定结果表明，MaROP6转基因毛状根的平均相对表达量为对照的36.87倍。毛状根转化体系的建立为白花草木樨基因功能的验证奠定了基础。     

农杆菌介导霞多丽葡萄胚性细胞系遗传转化条件的优化

为建立葡萄(Vitis vinifera)遗传转化技术体系,以霞多丽葡萄(Chardonnay)胚性细胞系为靶组织,采用GUS检测法,对影响农杆菌介导葡萄遗传转化效率的主要因素进行了研究。结果表明,超声波处理时间长短对转化效率有较大影响,在所试的0.5、1、5、10 min 4种不同时间的超声波处理中,以5 min时转化效率较好,平均达到9.11个蓝色斑点;AS浓度对转化效率有明显差异,当浓度为50μmol/L时,平均蓝色斑点数为8.89个,100μmol/L时,达到12.44个;DTT质量浓度对转化效率也有较大影响,在所试的3种质量浓度(1,2,3 mg/L)中,以3 mg/L为最佳,有16.67个蓝色斑点。通过GUS瞬时表达检测,确立了农杆菌介导葡萄胚性细胞系遗传转化的几个最适影响因素,从而为葡萄遗传转化技术体系的建立奠定了基础。     

影响根癌农杆菌介导香蕉胚性悬浮细胞遗传转化的因素

用含质粒载体pCAMBIA1301的根癌农杆菌EHA105转化贡蕉(Musa A A Pisang Mas cv. Mas)品种的胚性悬浮细胞,通过测定GUS基因瞬时表达率,对转化初期的主要影响因素进行了研究。结果表明,取处于对数期的胚性悬浮细胞和D600nm为0.2的菌液混合,在室温、8000r/min离心5min,然后在110r/min的旋转摇床上摇5min,在体细胞胚诱导培养基上共培养8d,瞬时表达率达到最高值25.30%。     

瓜类蔬菜组织培养与遗传转化研究进展

概述了瓜类蔬菜组织培养过程中的主要影响因素—基因型、外植体类型,部位与生理状态、培养基、生长调节物质、碳源及其他添加物质对植株再生的影响,以及根癌农杆菌介导的瓜类蔬菜遗传转化的影响因素与研究进展。     

黄瓜棒孢叶斑病病原菌RFP标记转化株的构建

由多主棒孢(Corynespora cassiicola)侵染引起的黄瓜棒孢叶斑病已成为我国黄瓜生产上的重要新流行病害,目前尚缺乏抗性品种,病原菌侵染机制及与寄主的互作关系尚不清楚。为了开展多主棒孢的病原学研究,本试验采用农杆菌基因介导技术(ATMT),获得了红色荧光蛋白(RFP)标记的多主棒孢转化株,转化株在PDA培养基转接6次后仍能在菌丝和分生孢子上发出强烈的红色荧光,生物学测定和致病性测定结果表明该转化株与野生型菌株无显著差异。     

DREB2A基因对苜蓿遗传转化的研究

以黑龙江紫花苜蓿Medicago sativa主栽品种:肇东苜蓿、敖汉苜蓿、公农1号和公农2号为受体材料,系统地探讨了除菌剂种类和浓度以及卡那霉素筛选浓度等,建立了高效的苜蓿再生体系和遗传转化体系;分别构建了由诱导型启动子rd29A和组成型启动子E12调控的DREB2A基因的2个植物表达载体pB2A29A和pB2AE12;采用农杆菌介导法进行遗传转化,获得大量转基因抗性植株并进行了分子生物学(PCR和Southern blot)检测.结果表明,DREB2A基因已整合到苜蓿基因组中.     

Inheritance and expression of transgenes in T2 and T3 generations of Lotus corniculatus transformed using Agrobacterium tumefaciens

The inheritance and expression of the reporter gene uidA, encoding β-glucuronidase (GUS), was previously analysed in the T₁ generation of 25 independent transformed lines of Lotus corniculatus cv. Leo. In the work reported here, GUS activity in various tissues of seven of these lines was tested in the T₂ generation. Four representative lines were chosen for more detailed study in the T₃ generation. Lines 25 and 38 had multiple, independently segregating transgene inserts; lines 24 and 39 appeared to transmit one segregating transgene insert to their T₁ progeny, although transgene expression was low and was detected in fewer seedlings than expected in line 39. The uidA gene was inherited and expressed in seedlings of T₁, T₂ and T₃ generations of all four lines. In all lines, transgene expression varied between tissues, with more embryos than seedlings having detectable GUS activity. Studies in the T₂ generation showed that use of transgenic plants as female or male parents altered the frequency of expression of the transgene in progeny. By contrast, in the T₃ generation the use of transgenic plants as female or male parents did not effect either frequency of transmission, or expression of the transgene, in any of the four lines. Transgene inheritance was also similar among individual pods within flower heads and between individual flower heads. This revised version was published online in July 2006 with corrections to the Cover Date.     

Evidence of Migration and Endophytic Presence of Agrobacterium tumefaciens in Rose Plants

Agrobacterium tumefaciens was isolated from stem tumors of several rose cultivars showing that the bacterium is the causal agent of aerial galls in rose plants. No differences were observed in the characteristics of the Agrobacterium isolates from crown or aerial galls. Stem inoculation of ten rose cultivars showed that all of them were susceptible to A. tumefaciens but differences in the size of the resulting tumors were observed. The movement of A. tumefaciens in rose plants was demonstrated using two wild type strains and two antibiotic resistant mutants. Three months after inoculation, the inoculated strains were recovered in the roots, crown and below and above the inoculation site but low numbers of pathogenic Agrobacterium cells were isolated. New tumors appeared in 5% of the noninoculated wounds. A. tumefaciens was isolated from the stem at different distances from the tumor in naturally infected plants. In symptomless commercial plants, the isolation from the roots, crown and at different stem levels demonstrated the existence of systemic and latent infections in rose. Direct isolation using a nonselective and selective media with or without a previous enrichment step were efficient methods for isolating tumorigenic Agrobacterium from the different parts of rose plants.     

根癌农杆菌介导的西瓜遗传转化研究进展

介绍了根癌农杆菌介导的西瓜遗传转化的研究现状,综述了西瓜高效再生体系的建立和遗传转化过程中的主要影响因素,包括最佳外植体的选择、最适培养基的制备,以及抗生素、农杆菌菌株类型、菌液浓度、侵染时间、预培养时间、共培养时间和添加乙酰丁香酮等内容,讨论了西瓜遗传转化存在的问题,并对这一体系的发展进行了展望。