油菜基因工程研究进展

近年来,油菜的遗传转化研究日趋成熟,用于转化的目的基因趋于多样化,如：品质改良、抗病、抗逆、不育基因等;较常用的筛选标记基因是新霉素磷酸转移酶基因(NPT II);目前油菜已建立了子叶、下胚轴、茎段、原生质体培养、小孢子培养的再生体系;用于油菜基因转化的方法根癌农杆菌介导法、基因枪法、PEG法、激光微束穿刺法、显微注射法等。本文主要对以上几个方面进行综述。     

菜豆组织培养及遗传转化研究进展

笔者概述了近年来国内外菜豆组织培养及菜豆遗传转化研究进展。重点阐述了菜豆组织培养过程中外植体选择、分生组织培养、愈伤组织的诱导、不定芽的诱导、生根培养及移栽等方面的研究成果。同时总结了农杆菌介导法和基因枪法2种遗传转化方法在菜豆转基因方面的应用情况。指出了基因型的差异是菜豆组织培养及遗传转化的主要限制因素,因此如何建立一套不存在基因型差异的菜豆再生体系,是今后菜豆组织培养和遗传转化的研究重点。     

葫芦科植物的遗传转化研究进展

葫芦科植物中包括多种以采收果实为主的蔬菜作物，对其进行品质改良、延迟成熟和抗病虫害的遗传转化研究具有重要的理论和实践意义。目前，在葫芦科植物中已建立了子叶、茎尖、胚轴、茎段、原生质体和子叶节等的再生体系；用于遗传转化的方法有农杆菌介导法、基因枪法、花粉管通道法、DNA浸泡法等；用于转化的目的基因多为抗病毒病基因和延迟成熟的基因；NPTII基因为最常用的筛选标记基因。主要对以上几个方面进行综述，并讨论了葫芦科植物遗传转化过程中的影响因素及存在的问题。     

转基因技术在大豆育种上的应用与研究

近年来,转基因技术在大豆上的研究重点主要集中在建立高效再生体系和稳定地遗传转化体系方面,随着遗传转化技术的发展,我国已获得了抗病、抗虫转基因的大豆植株并取得突破性进展。笔者就大豆遗传转化在受体系统(器官发生受体系统、体细胞胚胎发生受体系统、原生质体受体系统)以及转化方法(农杆菌介导法、基因枪法)等方面的研究进展情况进行了综述,并对今后大豆转基因研究方向进行了探讨。     

水稻常用的遗传转化技术及应用现状

1988年，三个独立的研究小组 率先报道获得了转基因水稻植株（Toriyama等,1988，Zhang,等,1988，Zhang等, 1988）。 十多年来，基因转移技术体系的建立一直是转基因水稻研究的重点。 在遗传转化技术应用方面，前期以采用原生质体为材料的PEG法和电激法为主，但原生质体 培养及再生对基因型依赖很大，转基因株育性较低；中期基因枪法得到了很大发展，迄今还 是单子叶植物首选的基因转化方法之一；而自90年代中期以来，农杆菌介导法在水稻基因转 移中日趋成熟，Hiei等（1994）创造的高效转化技术，首次证实了利用农杆菌转化水稻的 可行性，之后该法得到了广泛的应用。目前，水稻转化中应用比较普遍的方法有基因枪介导 法和农杆菌介导法。     

转基因林木中安全标记基因的研究进展

近年来,林木转基因研究进展迅速。但是,由于基因工程技术中使用选择标记基因可能对生态、环境、非靶标生物等带来危害,标记基因的安全性问题已越来越受到人们的关注。据报道在基因工程研究特别是植物转基因研究中使用安全标记基因遗传转化系统方面已作了大量尝试。本文主要综述林木植物转基因研究中应用安全标记基因遗传转化系统的研究现状,重点介绍了正选择标记的使用,可重组系统去除标记基因,利用位点特异性重组去除叶绿体DNA中标记基因的叶绿体遗传转化表达载体系统,及未来基于高转化率和大量快捷PCR筛选的完全无选择标记基因的遗传转化体系等研究进展与应用前景。     

农杆菌介导大豆遗传转化研究进展及其应用

农杆菌介导是大豆遗传转化的主要手段。近几年来大豆遗传转化方法得到了快速发展,但是仍然存在受体基因型匮乏、转化效率低,再生系统不完善等问题,为了进一步探讨大豆遗传转化的主要问题和策略,本研究归纳了近年来农杆菌介导大豆遗传转化在受体基因型及外植体选择,菌株筛选,标记基因选用和培养基组成等方面所做的改进,以得出有效的解决方法。并且介绍了农杆菌介导大豆遗传转化在作物改良和功能基因组学上的应用。     

花生基因工程研究进展

本文归纳了近十几年来国内外花生遗传转化方法,分析了不同方法的诱导效率和转化效果,概括了花生转基因研究进展并对其应用前景进行了展望。常用的花生转基因方法主要有3种,一是基因枪法转化胚性组织,二是农杆菌介导转化子叶(节),三是农杆菌介导转化茎尖(非组培)。花生基因工程转化的目的基因主要包括提高对病毒、真菌、干旱、除草剂等抗性的相关基因,在降低花生过敏原、提高油酸含量等品质改良和生物反应器生产免疫产品等方面也开展了探索性研究。花生体细胞胚诱导及再生和农杆菌介导的遗传转化技术日渐成熟,但花生的遗传转化体系仍存在转化效率低、受体基因型范围窄、后代遗传不稳定等问题,建立稳定、高效的转化平台是实现花生基因工程潜在价值的基础。     

双丙氨磷在橡胶树遗传转化中的应用

本研究以GV3101::pMP90RK为工程菌株,bar基因作为筛选标记基因,研究了双丙氨磷在橡胶树根癌农杆菌介导法转基因体系中对转基因愈伤组织的筛选效果,并利用该体系将橡胶树转录因子HbWRKY5转入橡胶树无性系热研8-79中。实验结果表明,3mg/L双丙氨磷可作为橡胶树转基因体系中抗性愈伤组织筛选的最佳浓度。本研究中共获得了3个抗性愈伤组织系,抗性愈伤经过体细胞胚发生共获得234个体细胞胚,经植株再生培养后共获得22株再生植株。对再生植株进行的PCR鉴定结果表明,所获得的再生植株均为转基因植株。因此,bar基因结合双丙氨磷的筛选体系可以作为橡胶树转化体系中的有效筛选体系。     

西瓜遗传转化的研究进展与展望

本文从外植体的选择、高效不定芽的诱导、伸长以及生根等方面综述了西瓜子叶农杆菌介导法的遗传转化再生体系的建立;介绍了GUS、NPTⅡ等各种标记基因,WMV-1、WMV-2、ZYMV、CMV等抗病基因和抗枯萎病南瓜总DNA、抗枯萎病瓠瓜总DNA、银杏总DNA和pBI121 DNA等外源基因的选择方法和外源基因在转基因西瓜中的遗传规律;讨论了在完善西瓜抗病育种的同时,其它抗逆、品质改良、控制生长发育等有益农艺性状在西瓜改良方面的应用,并对一些有价值的基因导入西瓜进行了展望。     

共转化法删除转基因植物筛选标记基因的研究

筛选标记基因因其在植物基因工程中的重要作用而得到了普遍应用,目前使用的筛选标记主要是抗生素抗性基因或抗除草剂基因,然而一旦获得转基因植株,它的存在不但没有必要,而且还引起人们的种种顾虑。因此如何从转基因植物中删除筛选标记基因成为植物基因工程研究的重要内容。目前已有多个系统用来删除选择标记基因,从而获得无筛选标记基因的转基因植株。其中共转化法操作简便因而得到了广泛的应用。本文综述了共转化法研究的最新进展并对其实际应用的可行性进行探讨。     

Coat protein-mediated protection against plum pox virus in herbaceous model plants and transformation of apricot and plum

Summary The expression of the viral coat protein gene in transgenic plants has been shown to induce tolerance against virus infection (Beachy et al., 1990). Transgenic plants ofNicotiana clevelandii andNicotiana benthamiana- herbaceous host plants for PPV - transformed withAgrobacterium strain LBA 4404 containing the plasmid pBinPPVm, regenerated on selection media containing kanamycin were tested for the expression of the PPV coat protein gene by ELISA and immuno western blot. After rooting and acclimatisation plants were tested for the protection against PPV Following the inoculation plants were investigated for symptom development and virus accumulation. Different lines were identified, according to the different reaction to the mechanical inoculation, ranging from a complete absence to a strong reduction of symptoms. There have not been many reports on transformation of trees in general, and in fruit trees particularly. It is obvious that the major obstacle is the regeneration of transformed plantlets. Attempts to improve crop plants by genetic engineering techniques will always depend very strongly on the availability of reliable protocols for transformation, selection and regeneration (Laimer et al., 1989, 1990). Different systems involving juvenile and adult plant material have been developed allowing the transfer of foreign genes into apricot and plum cultivars. We report the transformation and regeneration ofPrunus armeniaca andPrunus domestica plants withAgrobacterium tumefaciens strain LBA 4404 containing various binary plasmids, pBinGUSint, carrying the marker geneβ-glucuronidase (GUS) and pBinPPVm, carrying the coat protein gene of Plum Pox Virus (PPV), the causal agent of Sharka disease. The marker geneGUS was used for the optical evaluation of the efficiency of different transformation systems involving cotyledons of immature embryos as well as somatic embryos and leaf discs. The coat protein gene of PPV was used to introduce the coat protein mediated resistance against one of the most important pathogens of stone fruit trees in Europe and the whole Mediterranean area.     

Molecular markers and doubled haploids in European plant breeding programmes

The breeding companies and laboratories involved in this article cover a wide range of crops grown in the temperate climate zone: small grain cereals, oilseed crops, forage crops, turf, vegetables and potato. Speed and efficiency are becoming increasingly important in variety breeding and doubled haploids (DH) and genetic markers are important biotechnological tools to accelerate materials to market. Collaborative research between universities, research institutions and breeding companies has resulted in the routine use of DH technology and molecular markers in practical breeding of barley, wheat and rapeseed. DH populations have been established not only for barley, wheat and rapeseed, but for rye, oat and triticale, where DH technology is less developed. A driver here is the value of the crop e.g. although wheat is less responsive to DH production the value of the end product makes the effort worthwhile. Simple and rapid DNA extraction methods used in high-throughput marker assisted selection (MAS) systems are essential for routine use of markers. MAS is used both to monitor the presence of genes of interest and also to monitor the genetic background. DH technology in forage, turf and vegetables is still in progress and the practical use of markers in all crops is limited by access to trait linked markers. Collaboration and technology transfer with universities, research institutions and breeding companies is essential for the improvement of both DH protocols in recalcitrant crops and marker technology in all crops.     

Functional genomics of microspore embryogenesis

Isolated plant microspores, when stressed and cultured in vitro, can be diverted from their normal gametophytic pathway towards sporophytic development, with the formation of haploid embryos and ultimately doubled-haploid plants. This process is called androgenesis or microspore embryogenesis, and is widely used in plant breeding programmes to generate homozygous lines for breeding purposes. Protocols for the induction of microspore embryogenesis and the subsequent regeneration of doubled haploid (DH) plants have been successfully developed for more than 200 species. These practical advances stand in stark contrast to our knowledge of the underlying molecular genetic mechanism controlling this process. The majority of information regarding the genetic and molecular control of the developmental switch from gametophytic to sporophytic development has been garnered from four intensely studied (crop) plants comprising two dicotyledonous species, rapeseed (Brassica napus) and tobacco (Nicotiana tabacum), and two monocotyledonous species, wheat (Triticum aestivum) and barley (Hordeum vulgare). In these species the efficiency of microspore embryogenesis is very high and reproducible, making them suitable models for molecular studies. In the past, molecular studies on microspore embryogenesis have focussed mainly on the identification of genes that are differentially expressed during this developmental transition and/or early in embryo development, and have identified a number of genes whose expression marks or predicts the developmental fate of stressed microspores. More recently, functional genomics approaches have been used to obtain a broad overview of the molecular processes that take place during the establishment of microspore embryogenesis. In this review we summarise accumulated molecular data obtained in rapeseed, tobacco, wheat and barley on embryogenic induction of microspores and define common aspects involved in the androgenic switch.     

花生组培再生及农杆菌介导遗传转化研究进展

农杆菌介导法是花生遗传转化最常用的转化方法,近年来,花生农杆菌介导转化技术日渐成熟,但仍存在再生体系不完善,以及转化效率低和基因型限制等难题。为了建立高效的再生和遗传转化体系,本文归纳了近十几年来国内外花生组织培养及农杆菌介导转化方法,分析了不同方法的诱导效率和转化效果,认为花生体胚转化体系可以提高外源基因的遗传稳定性,并克服嵌合体等问题。在现有的组培再生基础上,对花生体胚诱导再生进一步优化,建立高频的花生体胚再生体系,进一步提高花生的转化效率,建立标准化、规模化、工厂化以及可重复的安全高效转化体系,是花生遗传转化的发展趋势。     

小麦遗传转化研究进展

Gradual progress made in genetic transformation of wheat is presented in this paper. Information on promoters, antibiotic, herbicide and auxotrophic markers, and various traits of wheat modified through genetic transformation, is provided. In addition the methods used for wheat transformation are discussed. Though significant efforts have been made for genetic transformation of wheat mainly through particle bombardment method but transformation efficiency is still low for mass production of fertile transgenic plants. Studies on the inheritance of transgenes and its incorporation into commercial elite cultivars are not significant. Agrobacterium mediated transformation seems to have better prospects for wheat transformation in future due to its advantages over particle bombardment. In planta transformation of wheat tissues seems possible only with A grobacterium.