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关键词： 小分子物质   基因表达   盐诱导基因   植物   耐盐性  

摘要： 研究证明植物的耐盐机制十分复杂 ,它与植物的小分子物质的积累 ,离子摄入和区域化 ,以及基因表达和大分子蛋白质的合成有关 ,如调渗蛋白、通道蛋白、晚期胚胎发生富集蛋白。同时 ,利用克隆技术分离到了一些盐诱导基因。现将这部分工作做一综述。

关键词： 短穗竹属   生态地理分布   生物学特性   保护  

摘要： Eco\|geographical distribution, biological characters and conservation of \%Brachystachyum \%Keng were studied. The coverage of \%B. densiflorum \%forest increased from 40%～45% to over 90% through rejuvenesced method by conservation \%in situ; \%with the \%ex situ \%strategy, the total individuals of \%B. densiflorum \%var. \%villosum \%increased from 2 to 181 during 5 years (1989～1994), and its mean height reached 3.81 m, its basal\|diameter was 1.95 cm.

关键词： 病原真菌   毒性基因   无毒基因   防卫基因   信号传导  

摘要： 本文从病原真菌致病基因、无毒基因及产物的互作 ,植物抗性基因、防卫基因及产物间的互作 ,系统获得抗性 ,信号传导系统等方面 ,对植物与病原真菌互作的分子生物学及其进展进行了综合论述。

关键词： Cystic fibrosis   Lung transplantation   Maxillary antrostomies   Sinusitis  

摘要： The placement of maxillary antrostomies among cystic fibrosis (CF) patients has been used as a treatment to allow localized antibiotic lavage of infected sinus passages. This procedure is increasingly recommended by lung transplantation centers as a prerequisite prior to accepting a CF patient as a candidate for transplantation. Our study attempts to define the degree of identity between sinus, endotracheal and sputum cultures from 35 patients. The samples (n = 137) were collected within two weeks of each other. An analysis of the microbiologic type, strain, and antibiotic resistance patterns was undertaken. Randomization analysis was performed and a p-value of < 0.05 was considered significant. The results indicated a high degree of correlation between sinus-sputum pairs (n = 55) and endotracheal samples (p < 0.008). This study provides evidence that there is a potential for cross- infection between sinus passages and the lower airway. The localized irrigation of CF sinus cavities post-transplantation may be warranted in an attempt to reduce bacterial counts and potential direct infection of the allograft. However, it is unlikely that this will eliminate this risk because bacterial colonization continues and the CF trachea is another source of infection.

关键词： review   sex determination   dioecy   sex chromosome  

摘要： The majority of the world's flowering plants are hermaphrodite but many of them encourage cross pollination by means of spatial or temporal separation of eggs and pollen, or by genetically-controlled physiological incompatibility. A minority of species has taken the avoidance of self-pollination to its logical conclusion by evolving two distinct and sexually different forms (dioecy). In a very small number of plants, dioecy has been accompanied by the development of sex chromosomes. From the study of the development of male and female flowers of different species it is clear that there is no common underlying mechanism and that sex determination systems leading to dioecy have originated independently many times in evolution. This Botanical Briefing highlights new information from recent molecular approaches in the study of dioecy. (C) 2000 Annals of Botany Company.

关键词： Insect  

摘要： The phytophagous insect fauna of ferns has often been described as depauperate, and some have pointed to the paucity of evidence for adaptive radiation of insect groups feeding specifically on ferns. This paper examines the world's species of fern-specific Macrosiphum aphids and attempts to determine whether fern-feeding is a monophyletically derived trait in Macrosiphum. All sixteen species reported to feed on ferns, including three new species, were included in a cladistic analysis, along with fifteen other Macrosiphum species selected to represent the diversity of the genus, Papulaphis sleesmani (Pepper), because of its similarity to fern-feeding Macrosiphum, and Sitobion avenae (Fabricius), which was used as outgroup. The results gave good support for the monophyly of fifteen of the sixteen fern-feeders, and also supported a clade consisting of these fifteen fern-feeders plus Macrosiphum equiseti (Holman), an Equisetum-specific aphid. One species, Macrosiphum lapponicum Shaposhnikov, from northern Russia, was concluded to be unrelated to other fern-feeding Macrosiphum. Whether this species truly feeds on a fern requires confirmation. Taxonomic and biological notes are provided for all fern-feeding Macrosiphum of the world. These include one new combination, Macrosiphum cyatheae (Holman) comb.n., and three new species: Macrosiphum longirostratum sp.n. on Woodsia mollis and Woodsia sp. from Mexico (Michoacan), Macrosiphum miho sp.n. on 'Aspidium' sp. from the U.S.A. (Illinois) and Macrosiphum rebecae sp.n. on Adiantum sp. from Mexico (Michoacan). Keys to apterous and alate viviparae of Macrosiphum living on ferns are given.

关键词： Cell biology   Physiology   Plant science  

摘要： High concentrations of sodium chloride are toxic to most plant species. New insights into the mechanisms by which plants tolerate salt have emerged from the identification of genes in Arabidopsis thaliana that play a critical part in physiological resistance to salt. (C) 2000 Elsevier Science Ltd. All rights reserved.

关键词： 香木莲   红花木莲   濒危植物   生殖生物学  

摘要： 该文利用生殖生物学的方法对濒危植物香木莲和红花木莲的生殖过程进行了研究,并在此基础上探讨了其濒危机制及保护措施.(一)香木莲的生殖生物学研究;研究了西畴县法斗乡和马关县小吉厂村两个香木莲居群的生殖过程.1.大小孢子发生、雌雄配子体发育的研究;2.开花生物学特性的观察;3.花粉离体萌发;4.种子萌发实验;5.扦插繁殖.(二)红花木莲生殖生物学特性研究;1.大小孢子发生、雌雄配子体发育的研究;2.种子储藏与萌发.

关键词： 类异戊二烯   次生代谢   生物合成   分子调控   HMGR  

摘要： New advances in molecular biology of plant secondary metabolic pathway were summarized. The biosynthesis of artemisinin was used as an example, combined with the research work in the authors’ laboratory. Some new ways for producing plant secondary metabolites were proposed.