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关键词： 川东獐牙菜   生物学特征   植物学特征   中药材   龙胆科  

摘要： 目的 :研究川东獐牙菜的植物学和生物学特征 ,为川东獐牙菜的野生变家种提供依据。方法 :野外观察与试验地观察研究相结合。结果 :本文对川东獐牙菜的植物学特征和生物学特征进行了较系统的观察研究 ,并有一些新的发现。

关键词： 植物赤霉素   生物合成   信号传导   分子生物学  

摘要： 赤霉素 (GAs)在植物的种子萌发、茎的伸长和花的发育等许多方面起着非常重要的作用。最近几年 ,对GA生物合成及其信号传导途径相关基因的研究取得了惊人的进展。这些进展促进了对其生物合成及其信号传导途径的认识。GA生物合成相关基因的表达受到多种内源和外源因子的调控 ,其中研究较多的是发育阶段、激素水平和光信号等内源及环境因子的调控。GA信号传导通常处于抑制状态 ,GA信号通过去抑制作用激活该传导途径而促进GA刺激植物生长和发育。

关键词： Agroinfiltration   植物   分子生物学研究   应用   瞬间表达  

摘要： 农杆菌渗入法 (Agroinfiltration)是近几年发展起来的一项快速、高效、重复性好的植物瞬间基因表达系统 ,已应用于外源基因表达分析、防卫反应、基因沉默、启动子分析及分离新的防御基因等领域。介绍了Agroinfiltration的原理、技术及其在植物分子生物学研究中的应用 ,并结合我们的经验介绍了对该项技术的改进。

摘要： Plants must withstand attack by a huge assortment of pathogens (viruses,bacteria, fungi, nematode worms, parasitic plants) as well as predation by herbivores such asinsects. To resist assault, plants have a group of resistance (R) genes that act in response toperception of complementary avirulence (avr) genes expressed by pathogens. Early genetic studies onthe interaction of plants with pathogens suggested that the R genes encode highly selectivereceptors that detect the presence of pathogens. Activation of these receptors switches on signalingpathways that set in motion a variety of host defenses, including the hypersensitive necrosisresponse. The cloning and characterization of the first plant R genes and pathogen avr genes largelyconfirmed this model and represented a historic advance in the field of plant pathology. However,there is still much to learn about the intervening signaling pathways that connect initialperception of the pathogen to the plant's ability to resist attack. A big step forward is presentedby Azevedo et al. (1) and Austin et al. (2) on pages 2073 and 2077 of this issue, with their reportsthat protein degradation may be a key regulatory event in the R gene-triggered signaling pathwaysof plant defense responses.

关键词： 现代分子生物学技术   植物抗病毒育种   作用   转基因植物  

摘要： 概述了近年来利用分子生物学技术进行抗病毒育种的几种主要方法及其研究进展 ,主要内容有外壳蛋白介导的抗性、利用缺损的复制酶、干扰运动蛋白、RNA介导的抗性、卫星RNA介导的抗性、反义RNA介导的抗性。

关键词： 鼎湖山自然保护区   胡椒属植物   生物学特性   外部形态   染色体数目   花粉形态   繁植方法  

摘要： 研究了鼎湖山自然保护区分布的 8种胡椒属植物的外部形态 ,根尖和茎尖细胞的染色体数目 ,花粉外部形态和繁殖保护方法 。

关键词： 生物学功能   硒   存在状态   营养学  

摘要： 本文叙述硒不仅是人和动物不可缺少的元素之一,也参与和调节植物的生长发育,对于动植物具有多种生物学功能,过量或不足对于生物都会产生不良的影响。本文重点介绍硒的存在状态及特点,营养学功能,硒与癌症的关系,硒的毒性生物功能以及硒在植物体内的生理生化作用。

关键词： 影响因素   植物雌激素   生物学效应   食品  

摘要： 目的 :了解食品中植物雌激素的生物学效应及其影响因素。方法 :查阅文献 ,综合论点。结果 :综述了食品中的植物雌激素的生物学效应及检测方法、影响因素。结论 :许多食品中存在的植物雌激素 ,其影响因素较多 ,可用高压液相色谱检验 。

关键词： boron   function   structure   essentiality   membrane   uptake   transport   cell wall   reproduction  

摘要： The interest of biologists in boron (B) has largely been focused on its role in plants for which B was established as essential in 1923 (Warington, 1923([153])). Evidence that B has a biological role in other organisms was first indicated by the establishment of essentiality of B for diatoms (Smyth and Dugger, 1981([138])) and cyanobacteria (Bonilla et al., 1990([14]);Garcia-Gonzalez et al., 1991([44]);Bonilla et al., 1997([16])). Recently, B was shown to stimulate growth in yeast (Bennett et al., 1999([8])) and to be essential for zebrafish (Danio rerio) (Eckhert and Rowe, 1999([33]);Rowe and Eckhert, 1999([121])) and possibly for trout (Oncorhynchus mykiss) (Eckhert, 1998([32]);Rowe et al., 1998([120])), frogs (Xenopus laevis) (Fort et al., 1998([41])) and mouse (Lanoue et al., 2000([75])). There is also preliminary evidence to suggest that B has at least a beneficial role in humans (Nielsen, 2000([96])). While research into the role of B in plants has been ongoing for 80 years it has only been in the past 5 years that the first function of B in plants has been defined. Boron is now known to be essential for cell wall structure and function, likely through its role as a stabilizer of the cell wall pectic network and subsequent regulation of cell wall pore size. A role for B in plant cell walls, however, is inadequate to explain all of the effects of B deficiency seen in plants. The suggestion that B plays a broader role in biology is supported by the discovery that B is essential for animals where a cellulose-rich cell wall is not present. Careful consideration of the physical and chemical properties of B in biological systems, and of the experimental data from both plants and animals suggests that B plays a critical role in membrane structure and hence function. Verification of B association with membranes would represent an important advance in modern biology. For several decades there has been uncertainty as to the mechanisms of B uptake and transport within pl

关键词： 甜菜碱合成酶   胆碱单加氧酶   甜菜碱醛脱氢酶   分子生物学   植物基因工程  

摘要： 甜菜碱是一种非毒性的渗透调节剂。多种高等植物在盐碱或缺水的环境下在细胞中积累甜菜碱 ,以维持细胞的正常膨压。甜菜碱的积累使得许多代谢中的重要酶类在渗透胁迫下能保持活性。在植物中甜菜碱由胆碱经两步氧化得到 ,催化第一步反应的酶是胆碱单加氧酶 (CMO) ,催化第二步反应的酶是甜菜碱醛脱氢酶 (BADH)。本文综述了这两种酶的分子生物学及基因工程研究的最新进展 。