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关键词： 南瓜韧皮部特异性启动子   增强子   抗虫植物表达载体   分子生物学检测   分子生物学  

摘要： 南瓜韧皮部蛋白PP2是一种在植物韧皮部特异性表达的蛋白质,将该基因启动子的839bp片段进行了缺失分析,结果表达在-467bp到-177bp之间可能存在增强启动子活性的区域,并在此基础上将-467bp~-177bp区域进行了加倍处理,构建了增强型NPP2启动子,该启动子驱动的GUS活性是原长启动子的6倍,是CoYMV启动子活性的3.2倍,是35S启动子的1.2倍.因此,NPP2启动子是一种有潜在应用价值的韧皮部特异性启动子.为对其表达活性及特异性进行进一步的确证,对其转基因子代烟草进行了一系列分子生物学检测.Southern blot结果表明,该启动子驱动的GUS基因可以遗传给子代,并有1~2个拷贝.GUS组织化学染色表明,该启动子仍然具有组织特异性,在转基因烟草的根、茎、叶、花等组织中都表现出明显的组织特异性.GUS活性检测显示,该启动子的GUS活性是35S启动子的1.4倍,是CoYMV启动子的4倍,表明该启动子是一种强启动子,具有潜在的应用价值.在上述实验的基础上,利用增强型NPP2启动子构建了pBdENP-ACA、pBdENP-GNA、pBdENP-ACA+GNA 3种抗虫植物表达载体,并以农杆菌介导转化获得了转基因烟草.

关键词： 植物花色   生物化学   分子生物学机制   改良   基因工程  

摘要： 文章综述了植物花色基因工程改良的前提、策略和特殊性。植物主要花色色素类黄酮、类胡萝卜素的合成途径和相关酶的基因表达已基本研究清楚,关键酶的基因已被克隆。花色的基因工程改良遵循一般植物基因工程规律,而且是系统工程,要求花器官特异性启动子,基本策略为抑制关键酶的基因表达、导入调节基因或新的外源基因。花色基因工程可能成为获得雄性不育的方式之一,应与传统育种技术有机结合,当然也存在安全性问题。

关键词： 植物源性疫苗   生产   分子生物学技术   发展现状   制作方法   运输   存贮  

摘要： 传统疫苗在制作、运输、存贮和使用中手续复杂、要求严格、成本高 ,且存在疫苗反应和疫苗复苏致病的可能性 ,因此无法最大限度地推广和普及。而利用微生物或动物细胞生产基因工程疫苗成本更高 ,难度更大 ,只是在对付人类一些重大疾病时才不得已而为之。如果应用分子生物学技术把重组疫苗基因导入植物 ,使其大量表达 ,生产出植物源性疫苗 ,就有望解决上述问题。植物源性疫苗一旦研制成功 ,便可通过大田栽培转基因植物而获得。人们可直接食用这种植物或其产品获得免疫力。目前已有部分植物源性疫苗在小鼠和人体上小规模实验取得成功 ,虽然植物源性疫苗的生产走上规模化道路还存在一些技术问题有待解决 ,但从长远来看 ,前景可观。

关键词： 植物   种群生态学   遗传学   《简明植物种群生物学》  

摘要： ***和***的<简明植物种群生物学>(Introduction to PIant Population Biology)第四版,已经由B1ackwell Publishing(Oxford)公司于2001年出版发行了.

关键词： aminopeptidase   hsp90   resistance   ribosomal DNA   sterol   systematics  

摘要： The recent de-registration of several chemical nematicides and the impending loss of methyl bromide from the pest-control market necessitate the development of new methods for controlling nematode-induced crop damage. One approach for developing novel target-specific controls is by exploiting fundamental differences between the biological processes of nematodes and their host plants. Researchers of the Agricultural Research Service (ARS) of the US Department of Agriculture are actively exploring these differences. Research accomplishments include the discovery of heat shock protein genes possibly involved in developmental arrest of the soybean cyst nematode, the identification of neuropeptides and female-specific proteins in the soybean cyst nematode, the disruption of nematode reproduction with inhibitors of nematode sterol metabolism, the development of novel morphological and molecular (heat shock protein genes and the D3 segment of large subunit ribosomal DNA) features useful for nematode identification and classification, and the elucidation of the population genetics of potato cyst nematode pathotypes. In addition, several ARS researchers are investigating biological determinants of nematode response to management strategies utilized in agricultural fields. These collective efforts should lead to new chemical and non-chemical alternatives to conventional nematode control strategies.

关键词： Eryngium cuneifolium   Florida scrub   Hypericum cumulicola   Liatris ohlingerae   mating system  

摘要： We investigated the reproductive biology of three plants endemic to rosemary scrub habitats on the Lake Wales Ridge of Florida, USA. We used hand-pollination experiments and observations of flowers and their insect visitors to determine their mating systems and pollination. Fruit or seed set after self pollination was 94, 97, and 8% of fruit or seed set after cross pollination in Eryngium cuneifolium (Apiaceae), Hypericum cumulicola (Hypericaceae), and Liatris ohlingerae (Asteraceae) respectively, indicating that the first two are self-compatible and the last is obligately outcrossing. All three depend on insects for seed production (4-7% fruit or seed set without insects). Diverse insects visit flowers of E. cuneifolium (101 species recorded), whereas L. ohlingerae is visited predominantly by butterflies and H. cumulicola by one genus of bees (Dialictus, Halictidae). Our data indicate pollinator visitation does not currently limit seed production in E. cuneifolium or H. cumulicola, but does in L. ohlingerae. Despite the features they share (habit, habitat, disturbance regime), we found unique aspects of these species' reproductive biology yielding unique risks to population viability. We suggest that. multispecies recovery plans must consider several aspects of the biology of species with superficial similarities to be successful. (C) 2003 Elsevier Science Ltd. All rights reserved.

关键词： .Plant Biology   become   partial   Challenge   st century   achieving   Silico Plant  

摘要： The challenges faced by Earth have never been more acute than they are now at the dawn of the 21st century. In silico plants may provide a unique albeit partial solution to several of the most daunting problems that we will face in the coming decades (the scarcity of oil and freshwater and the need to pro- duce more food). Although there is no single solution to these emerging problems, systems biology is a vehicle for gaining advanced knowledge of mecha- nistic plant biology that may provide the scientific basis for such partial solutions. There is already am- ple evidence that plant productivity can be further enhanced for food, feed, and fiber production and that an increased understanding of biotic and abiotic stress tolerance mechanisms may allow us to produce more food with less water (Somerville and Briscoe, 2001). However, to engineer plants with foresight and within the requisite timeframe, we need to achieve a comprehensive understanding of how plants work. We need to understand plants so thor- oughly that we can accurately predict how they will respond to any given genetic manipulation or envi- ronmental perturbation. We must progress from sim- ply trying to understand the function of each element in a plant individually to trying to understand how all these elements work together in the living plant. Only in this way can we maximize the usefulness of plants to benefit humanity in a realistic time frame. What do we need to begin the path from our current understanding of the parts of plants to a synthesis that allows the understanding of their interactions We require the development of new high-throughput experimental tools and approaches to gather and con- figure data, with contributions from the traditional individual investigator and through consortium ef- forts. We require improved and facile plant cell imag- ing techniques to dynamically track interacting pro- teins, metabolites, and cellular processes. We require advances in computational biology to

关键词： 厚皮香   繁殖生物学   胚胎发育   人工繁殖  

摘要： 对厚皮香(Ternstroemia gymnnanthera)昆明西山居群与筇竹寺山居群进行野外繁殖生物学以及室内胚胎学与人工繁殖技术研究结果表明:1.在所观察的居群中,厚皮香可以生长于林缘阳坡、林下荫蔽环境以及裸地阳坡三种环境中,以林缘阳坡与裸地阳坡环境内厚皮得有性生殖与无性生殖均良好.2.在自然条件下厚皮香有性生殖正常,有单性花与两性花;自然居群中有较高结实率和结籽率,但结实率与结籽率在不同居群,不同个体以及个体内不同枝条上均有差异,在生境条件适合情况下,厚皮香可通过较长的地下根茎来进行繁殖.3.厚皮香异花授粉.其传粉虫媒为蜂类,通过野外试验发现也存在风媒的情况,由于缺乏自花授粉的机制,存在一些形态变异方面的传粉机制来保证异花授粉的进行.4.根据厚皮香植物果实为浆果状蒴果,种子有红色的假种皮,而种皮较木持化较硬,以及实地观察与解剖观察来看,推测种子的散布为可能是鸟类散布.5.进厚皮香胚胎学情况是:花药为四小孢子囊;花药壁发育为双子叶型;花药表皮宿存并次生加厚,并单宁化;药隔细胞也有单宁细胞与结晶细胞;药室内壁细胞没有次生加厚,并一直宿存到散粉时,绒毡层为分泌型,双核,在小孢子形成后高度发育;小孢子原细胞2-3列,形成次生造孢细胞后发育为小孢子母细胞;小孢子母细胞减数分裂正常,同时型,形成四分体主要为四面体型,也有交叉十字型;成熟花粉为三细胞型.6.厚皮香人工繁殖情况是:连续两年采集了厚皮香一年生枝条与二年生枝条以及当年生种子进行了人工繁殖实验,插插繁殖用100PPm浓度NAA处理15分钟较好,并注意\"现采现插\"则扦插成活率会较镐 ,种子在土壤里的萌发较高,但存在3-4个月的休眠期,用800x10<\'-6>GA<,3>处理后种子可打破休眠.可以使用种子来育苗.

关键词： 盐胁迫   离子转运   离子平衡   耐盐性   转运蛋白   盐生植物   逆向转运  

摘要： 植物细胞质是生理生化反应的集中部位,植物的正常生长发育需要维持细胞内离子的相对平衡状态,而细胞质保持相对恒定的K+/Na+的能力是植物盐适应性的重要决定因素之一。各种离子的相对平衡是许多生理过程的综合结果,包括离子的内流、外流、外排和区域化等。离子的转运是由位于膜上的转运蛋白完成的,并受到多基因的调控。离子转运蛋白的分子生物学研究近年来发展很快,本研究将介绍有关方面的研究进展。

关键词： ABA   salt stress   transgenic plants  

摘要： Soil salinity is a major abiotic stress in plant agriculture strongly, influencing plant productivity world-wide. Classical breeding for salt tolerance in crop plants has been attempted to improve field performance without success. Therefore, an alternative strategy is to generate salt tolerant plants through genetic engineering. Several species and experimental approaches have been used in order to identify those genes that are important for salt tolerance. Due to high level of salt tolerance, halophytes are good candidates to identify salt tolerance genes. However, other species such as yeast and glycophytes have also been employed. Three approaches are commonly used to identify genes important for salt tolerance. The first approach is to identify genes involved in processes known to be critical for salt tolerance (osmolyte synthesis, ion homeostasis, etc.). The second approach is to identify genes whose expression is regulated by salt stress. This is relatively simply and applicable to any plant species. Genetic amenability of some species allows the third approach, which consists in the identification of salt tolerance determinants based on functionality. At the moment, there is a large number of reports in the literature claiming that plants with increased salt tolerance have been obtained. The main problem is that different plant species, stage of development, organs, promoters and salt conditions used it is difficult to compare the degree of salt tolerance conferred by different genes. In this review, we discuss progress made towards understanding the molecular elements involved in salt stress responses that have been used in transgenic approaches to improve salt tolerance.