转基因技术在作物抗旱改良中的应用

以不同靶标基因为例,分不同作用机制（诸如渗透调节和清除氧自由基等）简要介绍了近10年来国内外利用转基因技术改良作物耐盐和抗旱性的研究进展,为我国北方农业的抗旱耐盐性研究提供一些思路。     

南亚热带森林2种菌根类型树木水分传导和养分利用策略的对比研究

为揭示南亚热带季风常绿阔叶林在季节性干旱加剧和氮沉降增加等环境影响下,菌根树木优势度变化趋势机理,对3种优势EM树木黄杞（Engelhardtia roxburghiana）、锥（Castanopsis chinensis）、黧蒴锥（C. fissa）和3种优势AM树木云南银柴（Aporusa yunnanensis）、山蒲桃（Syzygium levinei）、广东金叶子（Craibiodendron scleranthum var. kwangtungense）的水力性状和养分性状进行了研究。结果表明,EM树木叶片导水率下降50%和88%时的水势（P₅₀、P₈₈）和膨压丧失点（Ψ_tlp）均低于AM树木,边材比导水率（K_S）、叶片比导水率（K_L）、光合氮利用效率（PNUE）和光合磷利用效率（PPUE）均高于AM树木。可见,EM树木比AM树木具有更强的抗旱能力以及更高的导水效率和养分利用效率,这可能是在干旱加剧和氮沉降增加背景下EM树木优势度增加而AM树木优势度减少的生理机制。     

基因工程与食品工业

就基因工程在食品工业中某些方面的应用及其安全性作了简要介绍     

转基因动物研究中存在问题

１５年来已建了许多用作研究人类疾病的转基因动物模型。转基因动物已作为研究代谢调节、分化、发育中有关基因功能的工具,它已作为一种分子农场可生产基因产品等。但要看到,转基因还有许多问题要解决。首先是转基因的阳性率低,这是受了许多因素如ＤＮＡ样品质量,分子大小和结构,动物种属,原核的可见性,注射针的调节和微注射技术等影响。通常转基因首建的阳性率在１０－２０％,有时甚至低于１％。在基因操作后,外源基因整合     

树木年代学的研究进展

我国树木年代学研究自20世纪90年代以来取得了长足进展,尤其是树木年轮气候学研究已经在国际上有一定影响.然而,我国树木年代学研究发展相对不均衡,其他树木年轮分支学科的发展相对较弱.本文综述国内外树木年代学不同分支学科研究进展,对比我国树木年代学研究现状和国际研究概况,为我国树木年代学不同分支学科的研究提出建议.我国未来树木年轮气候学研究应在开展大量不同区域树木年轮气候学重建基础上,尝试选用不同数理方法和多树木年轮指标(宽度、密度、同位素和木材解剖学指标)进行长时间尺度和大空间范围重建工作,并通过诊断方法和过程模拟方式讨论重建时段的气候机制.     

小议树木的作用

本文作者根据近些年来经济的迅速发展,给城市带来的负面效应——环境污染,已到了不容忽视的地步。危害人类的各种有毒气体大量增加,氧气被大量消耗;烟灰、粉尘、放射性物质、强烈致癌物漫天飞舞;光化学烟雾已在我国许多城市出现;我国百万以上人口城市中肺癌死亡率已升至癌症死亡率的第一位。要解决这些问题就必须做好生态美化绿化。     

Gene Flow,Risk Assessment and the Environmental Release of Transgenic Plants

The release of genetically modified plants is governed by regulations that aim to provide an assessment of potential impact on the environment. One of the most important components of this risk assessment is an evaluation of the probability of gene flow. In this review, we provide an overview of the current literature on gene flow from transgenic plants, providing a framework of issues for those considering the release of a transgenic plant into the environment. For some plants gene flow from transgenic crops is well documented, and this information is discussed in detail in this review. Mechanisms of gene flow vary from plant species to plant species and range from the possibility of asexual propagation, short- or long-distance pollen dispersal mediated by insects or wind and seed dispersal. Volunteer populations of transgenic plants may occur where seed is inadvertently spread during harvest or commercial distribution. If there are wild populations related to the transgenic crop then hybridization and eventually introgression in the wild may occur, as it has for herbicide resistant transgenic oilseed rape (Brassica napus). Tools to measure the amount of gene flow, experimental data measuring the distance of pollen dispersal, and experiments measuring hybridization and seed survivability are discussed in this review. The various methods that have been proposed to prevent gene flow from genetically modified plants are also described. The current “transgenic traits” in the major crops confer resistance to herbicides and certain insects. Such traits could confer a selective advantage (an increase in fitness) in wild plant populations in some circumstances, were gene flow to occur. However, there is ample evidence that gene flow from crops to related wild species occurred before the development of transgenic crops and this should be taken into account in the risk assessment process.     

转基因猪研究进展

转基因猪是指运用分子生物学技术方法,将人工分离或改造过的基因整合到猪的基因组中,并能稳定的遗传给后代。转入的基因可以使猪的某些性状向人类需要的目标发生转变,因此在猪的遗传育种、以及将猪作为药物评价、疾病模型、特异性药物生产的生物反应器和组织器官移植的供体等方面具有重要的作用。就目前转基因猪的研究进展、技术方法及应用现状进行简要的综述。     

基因工程技术在食品品质改良中的应用

概述了用基因工程技术改良食品的食用品质,提高食品加工性能的研究和应用现状。     

重组人超氧化物歧化酶化学修饰的初步研究

在高效表达重组人铜锌超氧化物歧化酶(rh Cu/Zn SOD),并纯化得到比活大于4000单位的 rh Cu/Zn SOD 纯品的基础上,采用活化酯法将聚乙二醇(PEG)与 rhCu/Zn SOD 交联,获得分子量约6万的 PEG-SOD 交联物.经 PEG 修饰的酶稳定性增强,表现为对酸、碱和热的耐受力均较未交联酶高.修饰酶的生物半衰期为15h,是天然酶的90倍,酶活性保留80%以上.还实验观察了修饰剂用量与修饰酶保留活性之间的关系.     

Time to start intervening in the human germline? A utilitarian perspective

Focusing on present-day possibilities raised by existing technology, I consider the normative aspects of genetically modifying the human germline from a utilitarian standpoint. With reference to a hypothetical case, I examine the probable consequences of permitting a well-conceived attempt to correct a disease-associated gene in the human germline using current CRISPR gene-editing technology. I consider inter alia the likely effects on utility of creating healthy new lives, of discouraging adoption, and of kickstarting a revolution in human germline genetic modification (HGGM). I reject various objections to HGGM, including claims that the risks of genetic harm outweigh the likely benefits. From this utilitarian analysis, I conclude that strong grounds exist to support intervening in the human germline using current technology. Delay in commencing such work will impose a utility cost, because the longer we wait until commencing the HGGM revolution and moving towards a world of increased utility, the greater will be the quantity of suffering accrued meantime through genetically influenced disease. Nevertheless, considering residual safety concerns and the negative publicity engendered by an ethically problematic recent (2018) first attempt at HGGM, it seems prudent—and ultimately generative of the greatest amount of utility—to delay implementing HGGM for a modest period of time, in the order of 1–2 years.     

转基因雄性不育系及其在杂种种子生产上的应用

雄性不育为农作物杂种优势的利用开辟了一条经济有效的途径。本综述了利用生物技术培育转基因雄性不育的多种策略,以及繁育用作大田配制杂交种的母本雄性不育系的新方法;探讨了其应用于商业化杂种生产的重要性及前景。     

转基因动物在生物制药工业中的应用

简要论述了转基因动物的概念、制作方法及应用领域,回顾了转基因动物技术的发展及现状,分析了转基因动物与克隆动物的区别.就转基因动物在制药工业和生物医药领域中的国内外研究与开发应用情况进行了阐述,同时展望了转基因动物制药的发展前景及对社会的影响.     

Transgenic approaches to improve the nutritional quality of plant proteins

Summary Plant proteins, when used as dietary protein, are generally incomplete in nutrition due to their deficiency in several essential amino acids, for example, lysine and tryptophan in cereals and methionine and cysteine in legumes. Attempts to breed crops with increased levels of lysine and methionine have been less than satisfactory. Modern biotechnology offers alternative approaches for rectifying this nutrition deficiency. In the past decade, several transgenic strategies aimed at modifying the amino acid composition of plant proteins and enhancing the content of specific essential amino acid(s) for nutrition improvement have been developed and tested. These include synthetic proteins, modification of protein sequences, over-expression of heterologous or homologous proteins, and metabolic engineering of the free essential amino acid pool and protein sink. The progress and potential of these approaches and studies are reviewed. As plant proteins are the primary source of all dietary protein consumed by humans and animals and are inexpensive to produce in comparison with meat, improving their quality will make a significant contribution to our future food needs. The research and development in this area of interest is making promising progress towards this endeavor.     

Phytoremediation of Metals Using Transgenic Plants

An ideal plant for environmental cleanup can be envisioned as one with high biomass production, combined with superior capacity for pollutant tolerance, accumulation, and/or degradation, depending on the type of pollutant and the phytoremediation technology of choice. With the use of genetic engineering, it is feasible to manipulate a plant's capacity to tolerate, accumulate, and/or metabolize pollutants, and thus to create the ideal plant for environmental cleanup. In this review, we focus on the design and creation of transgenic plants for phytoremediation of metals. Plant properties important for metal phytoremediation are metal tolerance and accumulation, which are determined by metal uptake, root-shoot translocation, intracellular sequestration, chemical modification, and general stress resistance. If we know which molecular mechanisms are involved in these tolerance and accumulation processes, and which genes control these mechanisms, we can manipulate them to our advantage. This review aims to give a succinct overview of plant metal tolerance and accumulation mechanisms, and to identify possible strategies for genetic engineering of plants for metal phytoremediation. An overview is presented of what has been achieved so far regarding the manipulation of plant metal metabolism. In fact, both enhanced metal tolerance and accumulation have been achieved by overproducing metal chelating molecules (citrate, phytochelatins, metallothioneins, phytosiderophores, ferritin) or by the overexpression of metal transporter proteins. Mercury volatilization and tolerance was achieved by introduction of a bacterial pathway. The typical increase in metal accumulation as the result of these genetic engineering approaches is 2-to 3-fold more metal per plant, which could potentially enhance phytoremediation efficiency by the same factor. As for the applicability of these transgenics for environmental cleanup, results from lab and greenhouse studies look promising for several of these transgenics, but field studies will be the ultimate test to establish their phytoremediation potential, their competitiveness, and risks associated with their use.