植物抗菌肽研究进展

植物抗菌肽是一类对细菌,真菌等微生物有抑制或杀灭作用的小分子多肽,它能被细菌,真菌或物理的,化学的刺激所诱导,有些抗菌肽甚至在植物体内能组成性的表达,从化学结构来看,植物抗菌肽要包括硫堇,植物防卫素,脂转移蛋白和橡胶素类等,它们抗菌能力强,有较好的耐热性,抗菌机理独特,在农业,医药及食品等领域有着广泛的应用前景。作者总结了国内外植物抗菌肽研究进展,对其应用研究的基因工程等方面作了阐述,并对进一步研     

新型抗菌肽基因设计、合成及其在酵母中的表达(Ⅰ)——杂合抗菌肽基因的设计与合成

以化学合成并证实抗菌活性和抗菌谱都高于天然抗菌肽的杂合肽ＣｅｃｒｏｐｉｎＡ１－１１Ｄ１２－３７的氨基酸序列为基础,选用酵母高频使用密码子设计了一种新型抗菌肽基因,基因合成采用二次ＰＣＲ（聚合酶链式扩增）方法．设计和合成的基因全长１４０个碱基对,包括氨基酸编码序列、起始密码子、终止密码子和两端限制性内切酶ＢａｍＨＩ、ＥｃｏＲＩ、ＳａｌＩ识别顺序,合成的基因克隆于ＰＣＲＴＭ２．１载体上．经ＤＮＡ序列分析证实,合成基因碱基序列与设计序列完全一致．     

抗菌肽的研究进展

抗菌肽具有分子量小、热稳定性好、抗菌谱广等特点,介绍了抗菌肽的组成结构、分类、生物学特性、抗病机制、基因工程、发展前景和存在的问题。     

植物抗病基因的几个结构域

研究抗病基因的结构对于植物抗病工程的发展具有很重要的价值。对已克隆出的植物抗病基因研究表明,大多数的抗病基因都具有高度保守的结构域,本文对在植物抗病反应中起主要作用的几个结构域(LRR域、TIR域、CC域、Kinase域和NBD域)做了简要阐述。     

植物抗虫基因工程研究与应用

近年来,植物抗虫基因工程研究及应用进展喜人.本文综述了利用Bt杀虫蛋白基因、豇豆蛋白酶抑制素基因、昆虫特异性神经毒素基因以及外源凝集素基因等抗虫基因开展植物抗虫基因工程研究的概况,并探讨了植物抗虫基因工程中存在的主要问题及解决的途径.     

NPR1基因研究进展

从拟南芥(Arabidopsis thaliana)中克隆到的NPRl基因是植物系统获得性抗性中的一个关键基因，它在植物抗病基因工程中将起到重要的作用。近年来，国内外许多学者对NPRl基因进行了较系统的研究。在此对NPRl基因的结构、作用机理、核定位以及与植物抗病性的关系等方面的研究进展进行综述，并展望它在抗病育种工作中的应用前景。     

表达千穗谷Ah—AMP基因的转基因烟草抗病性研突

通过PCR从苋属植物千穗谷(Amarathus hypochondriacus)的总DNA中扩增出苋菜抗菌肽(Ah—AMP)的核基因片段，序列分析结果表明该基因长261bp，编码一个由86个氨基酸组成的Ah—AMP前体多肽。在构建Ah—AMP基因的植物表达载体pBinAH916后，通过根癌土壤杆菌介导方法转化了烟草。转化再生植株和T1代转基因烟草的PCR和Southern blot分析表明，AA—AMP基因已整合到烟草的染色体中，并为单拷贝整合。T1代转基因烟草的Nouthern blot分析结果表明，AA—AMP基因在转基因烟草中至少在mRNA水平上能正常表达。对T0代转基因烟草进行烟草青枯病的抗病性试验，筛选出两株抗性较强的植株。对T1代抗青枯病的统计分析发现，其抗病性比起始品种SRl分别提高了2．24和1．62个级别；其病情指数比起始品种降低49．6％和37．3％。对黑烃病也表现一定的抗性，主要表现在推迟发病时间，减缓发病速度上。这些结果表明AA—AMP基因在植物抗病基因工程研究中可能是一个有潜在应用价值的基因。     

植物基因工程的研究进展与前景展望

植物基因工程是现代科学技术的重要支柱之一,是分子生物学、细胞生物学研究高度发展的产物,其迅猛发展引发了一场新的绿色革命浪潮,它为植物育种学开辟了一条崭新的途径.1 植物基因工程研究的总体状况从技术角度看,植物基因工程包括几个重要的环节:目的基因的分离和鉴定、基因的修饰及植物表达载体的构建、受体的遗传转化、基因工程细胞     

植物基因工程研究现状与展望

植物基因工程与人类生活密切相关,它将给植物育种带来革命性的变革。植物基因工程研究的关键问题是向植物中转移外源基因,它主要涉及植物受体的选择和基因转移方法的探索。由于Ti质粒载体的建立和应用,双子叶植物中的应用性研究已经取得了突破性的进展。单子叶植物方面的工作尚处于基础理论研究阶段。     

表达千穗谷Ah-AMP基因的转基因烟草抗病性研究

通过PCR从苋属植物千穗谷(Amarathus hypochondriacus)的总DNA中扩增出苋菜抗菌肽(Ah-AMP)的核基因片段,序列分析结果表明该基因长261bp,编码一个由86个氨基酸组成的Ah-AMP前体多肽.在构建Ah-AMP基因的植物表达载体pBinAH916后,通过根癌土壤杆菌介导方法转化了烟草.转化再生植株和T 1 代转基因烟草的PCR和Southern blot分析表明,Ah-AMP基因已整合到烟草的染色体中,并为单拷贝整合.T 1 代转基因烟草的Northern blot分析结果表明,Ah-AMP基因在转基因烟草中至少在mRNA水平上能正常表达.对T 0 代转基因烟草进行烟草青枯病的抗病性试验,筛选出两株抗性较强的植株.对T 1 代抗青枯病的统计分析发现,其抗病性比起始品种SR1分别提高了2.24和1.62个级别;其病情指数比起始品种降低49.6%和37.3%.对黑胫病也表现一定的抗性,主要表现在推迟发病时间,减缓发病速度上.这些结果表明Ah-AMP基因在植物抗病基因工程研究中可能是一个有潜在应用价值的基因.     

论我国烟草抗病毒基因工程

本文介绍了植物抗病毒基因工程的研究发展,对我国烟草工程研究现及发展前景作了论述。     

Disease-tolerance of transgenic tobacco plants expressing Ah-AMP gene of Amaranthus hypochondriacus

An antimicrobial peptide gene from Amaranthus hypochondriacus, Ah-AMP, was amplified by PCR and cloned. Sequence analysis results revealed that this gene is 261 bp in length encoding a precursor polypeptide of 87 amino acid residues. Ah-AMP gene was inserted in the binary vector pBin438 to construct a plant expression vector pBinAH916. Leave explants of Nicotiana tabacum var. SR1 were transformed with Agrobacterium tumefaciens LBA4404 harboring the above expression vector. Results from PCR, Southern and Northern blot analyses confirmed that the Ah-AMP gene had been integrated into the tobacco genome and was transcribed at mRNA level. Two bacterial-resistant transgenic plants were selected by inoculating the plants with Pseudomonas solanacearum and statistic analysis of two T1 lines showed that the resistance increased by 2.24 and 1.62 grade and the disease index decreased by 49.6% and 37.3% respectively when compared with the non-transformed control plants SR1. The results from challenging the plants with inoculums of Phytophthora parasitica showed that the symptom development was delayed and disease index was significantly reduced. These results suggest that Ah-AMP gene may be a potentially valuable gene for genetic engineering of plant for disease-resistance.     

凝集素的分离纯化、基因克隆及功能研究进展

凝集素(lectin)研究近年来发展迅速，尤其在植物基因工程中，植物外源凝集素基因越来越受到重视。本文从凝集素的分离纯化、基因克隆、理化性质和功能等方面进行了综述。此外还讨论了凝集素基因在植物基因工程中的应用。     

Research advances in genetic engineering of plantibody

The combination of engineering antibody and plant biotechnology creates the plantibody. It has been reported that the engineering antibodies expressed in plant, no matter whether they are intact or small-molecular antibodies, keep their antigen-binding specificity, which means they are functional. This trait makes plantibody notable. Now the researches are focused mainly on the following three aspects: (i) Therapeutic antibody in clinic. It is expected to offer the opportunity of large-scale antibody procluction in agriculture systems, for the purpose of decreasing the cost greatly. Moreover, the property of multiple sexual hybridization between plants can be used to produce bior multi-functional antibodies and create new antibody medicines. (ii) Plant physiology. Engineering antibodies against plant hormones or some active materials can block their activities in plant, so the trait of plantibody could be used to study the growth and development of plant. (iii) Plant disease-resistance. The gene of antibody against plant virus can be transferred into plant to defend the intrusion of virus in order to cure the disease.     

基因工程的发展现状和应用前景

介绍了＂基因＂和＂基因工程＂,从植物育种、动物育种、医学、保护生物多样性等6个方面阐述了基因工程的应用价值,对基因工程的研究前景进行了展望。     

Obtaining High Pest-resistant Tobacco Plants Carrying B.t. insecticidal Gene

To increase the expression level of CryIA(c) gene in transgenic plants, a plant expression vector pBinMoBc carrying the CryIA(c) gene under control of chimeric OM promoter and Ω factor was constructed. As a control, pBinoBc carrying the CryIA(c) gene with the CaMV 35S promoter was also constructed. The vectors were transferred into tobacco plants respectively via Agrobacterium-mediated transformation. ELISA assay showed that the expression level of the CryIA(c) gene in pBinMoBc transgenic tobacco plants was 2.44-times that in pBinoBc transgenic tobacco plants, and it could be up to 0.255% of total soluble proteins. Bioassay showed that pBinMoBc transgenic tobacco plants had more notable insecticidal effect than pBinoBc transgenic tobacco plants. The above results showed that the chimeric OM promoter was a stronger promoter than CaMV 35S promoter that was widely used in plant genetic engineering, and this is very useful in pest-resistant plant genetic engineering.     

生物技术与蔬菜品种的改良

叙述了通过基因工程,将各种外源基因转入蔬菜植株的体内,获得性状优良的品种。     

毛白杨4CL基因启动子的克隆及初步功能分析

4CL(4-coumarate:CoA ligase,4-香豆酸:辅酶A连接酶)在植物木质素合成途径中催化羟基香豆酸生成羟基肉桂酰CoA,主要在木质部中表达,对植物木质素生物合成具重要调控作用.为研究4CL基因启动子在转基因植物中的表达特性,探索其在植物基因工程研究中的潜在应用价值,利用PCR方法从毛白杨基因组DNA中扩增得到了4CL启动子片段.序列分析表明与美洲山杨(P.tremuloids)的4CL启动子同源性为95%.采用生物信息学方法对该序列进行分析.与GUS基因融合构建双元表达载体,转化烟草的瞬时表达检测可见明显GUS活性.     

Simple and effective detection method for gene expression product of transgenic plant

It is a crucial problem in gene engineering whether an exogenous gene could be correctly expressed in cells of transgenic animal or plant, and how the expression products could be detected quantitatively in translational level. It is very difficult to analyze some gene expression products, such as isopentenyl transferase (ipt), in transgenic investigation because they are trace in organisms. A convenient method is described to determine trace content gene expression product which is hard to purify. The method includes predicting and synthesizing the antigenic peptide according to the cDNA sequence, coupling the synthetic antigenic peptide with carrier protein, raising specific antibodies against the synthetic antigen, and detecting the gene expression product by ELISA and Western blot.