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关键词： 植物   胞质雄性不育   分子生物学   作物  

关键词： flavonol sulfotransferase   glucosinolate   choline sulfate   flavonoid   gallic acid  

摘要： It is now well established that, in mammals, sulfate conjugation constitutes an important reaction in the transformation of xenobiotics and in the modulation of the biological activity of steroid hormones and neurotransmitter (1, 2). The presence of a sulfate group on some molecules can also be a prerequisite for their biological function. For example, it is well known that the sulfate groups are directly involved in the molecular interaction between heparin and antithrombin III (3). In plants, sulfation also seems to play an important role in the intermolecular recognition and signaling processes, as indicated by the requirement of a sulfate moiety for the biological activity of gallic acid glucoside sulfate in the seismonastic and gravitropic movements of plants (4), and of Nod RM1 in the cortical cell division during early nodule initiation in Rhizobium meliloti-alfalfa interaction (5). In addition, recent studies indicate that flavonoid conjugates, including the sulfate esters, may play a role in the regulation of plant growth by strongly binding the naphthylphthalamic acid receptor, thus blocking the quercetin-stimulated accumulation of the auxin phytohormone (6). Although several sulfated metabolites are known to accumulate in a variety of plant species (7), the study of enzymes that catalyze the sulfation reaction in plants lagged considerably compared to those conducted with their mammalian homologs. This apparent lack of interest may have been because the function of plant-sulfated metabolites is difficult to predict, since their accumulation is often restricted to a limited number of species. Despite this limitation, several plant sulfotransferases (STs) have been characterized at the biochemical level, and the cDNA clones encoding six plant STs have been isolated. Based on sequence homology, the plant ST coding sequences are grouped under the SULT3 family, also known as the flavonol ST family. This review summarizes our current knowledge of the plant STs

摘要： Recent empirical studies hint at an end to the historical solitude between pollination and mating system approaches to plant reproductive character evolution. Now is an opportune time to distill theoretical results into comprehensible insight, and to integrate these findings into the emerging new plant reproductive biology. We outline four theoretical insights for understanding;the evolution of reproductive characters, and show how these allow researchers to dissect complex ecological scenarios into clear and evolutionarily relevant components.

摘要： Presents a brief summary of research on plant molecular biology in Tunisia, Morocco, and Algeria. Molecular study of PVY (potato virus Y), PVMV (pepper veinal mottle virus), CMV (cucumber mosaic virus) in Tunisia; Molecular analysis of resistance to Fusarium oxysporum in P. dactylifera in Morocco; Study of isozymes of cultivated and wild plants in Algeria.

关键词： Fabaceae/microbiology   Fabaceae/microbiology   Genome, Bacterial   Genome, Bacterial   Nitrogen Fixation/genetics   Plants, Medicinal   Plasmids/genetics   Rhizobium/genetics   Symbiosis  

关键词： 稀土元素   红豆杉细胞   紫杉醇   生物合成   抗衰老  

摘要： 该文主要侧重于研究稀土元素在植物细胞培养中对次生物质代谢的影响及其产生机理.选定的研究对象是具有很高开发价值的红豆杉细胞.研究方法采用植物细胞悬浮培养技术,通过高效液相色谱(HPLC)、圆盘聚丙烯酰胺凝胶电泳及透射电子显微镜等方法,研究了稀土元素对红豆杉细胞生长动力学、次生代谢产物紫杉醇合成与释放、次生代谢调控及细胞超微结构的影响.

关键词： 庙台械   濒危植物   花序   花  

摘要： 庙台械的花序为有限花序，由一顶花和6—9枝侧花枝组成，属圆锥状聚伞花序。一个花序共有14—29朵花，包括两性花、雄花和无性花三类花。根据花在花序上着生的位置，可分为三级。7月初，花序原基形成，在花序轴伸长的同时，侧面形成侧花枝轴原基。花序的顶花最早进行个体发育，随后是侧花枝顶花；侧花枝上同一级花的发育顺序则是从花序的下面向上进行。花器官发生时，花萼原基最先形成，然后是花瓣、雄蕊、心皮和胚珠。

关键词： Plants   Germination   Pollen   Anthers   Corolla   Fruits   Seeds   Calyx   Flowering  

摘要： The reproductive biology of two closely related Ajuga (Lamiaceae) species, Ajuga iva (L.) Schreber and Ajuga chamaepitys (L.) Schreber, was compared. Ajuga iva is a perennial, cleistogamous species that occurs relatively frequently in the southwest of the Iberian Peninsula, while A. chamaepitys is an annual, chasmogamous species that is rarely encountered in the same region. Flowers from the two species are homogamous and self-compatible. However, they exhibit substantial differences in their reproductive behavior. Ajuga iva produces two types of flowers: cleistogamous (CL) flowers that are obligately selfed, and chasmogamous (CH) flowers that are potentially outcrossed. CH flowers are produced in small numbers relative to CL flowers. Ajuga chamaepitys produces chasmogamous flowers only. However, if the flowers are not visited by insects within 1-2 d after anthesis, some changes in the relative disposition of the anthers and stigma lead to self-pollination, a rare occurrence in the Lamiaceae. The fruits produced by the two species are morphologically almost identical and are dispersed by ants. However, they differ significantly in germination, characteristics. Ajuga chamaepitys nutlets germinate under a wide range of conditions and in high proportions; A. iva nutlets, however, only germinate under highly restrictive conditions and at a very low percentage. There are no differences in nutlet dispersion or viability between the two species. These differences in germination characteristics may account for the qualitative and quantitative differences observed between populations of the two species in the southwest Iberian Peninsula.

关键词： Insect pollination   Honey bees   Plants   Pollinating insects   Insect pests   Bumblebees   Insect colonies   Forest insects   Pollen  

摘要： Looks at the mutualistic relationship between pollinators and plants. History of plant-pollinator mutualisms; Bees life history as being linked with those of flowering plants; Threats to pollinators; Habitat alteration; Agriculture; Grazing; Habitat fragmentation; Others; Degrees of dependence on pollinators; Examples of disrupted pollinator--plant interactions; Preservation of plant--pollinator systems.

关键词： 胡颓子科   翅果油树   生物学特性   珍稀植物  

摘要： 翅果油树为我国特有植物，已被列为国家二级重点保护树种。本文较系统地综述了翅果油树的生物学特性，包括其外部形态、内部结构、染色体核型、生长特性、地理分布、生态学和群落学特性、根瘤固氮活性及化学成分等。