教学课程资源库 更多>>

关键词： 植物防御素   抗菌活性   酶抑制剂活性  

摘要： 植物防御素是植物界中一类阳离子型多肽,在结构和功能上,它们与早先发现的哺乳动物和昆虫防御素类似。植物防御素的分子量在5kDa左右,其中含有8个保守的半胱氨酸残基。植物防御素的三维结构呈小球形,包括1个α-螺旋和3个反平行的β-折叠片层结构,8个半胱氨酸可以形成3对或4对二硫键,从而构成了Cys稳定的βαββ结构模序。从植物防御素的结构和体外生物学活性,可以看出植物防御素是一类十分复杂的多肽,它的作用不仅仅局限于植物免疫,而应具有广阔的应用前景。

关键词： 雄全异株   开花动态   维持机制   传粉机制   瘿椒树  

摘要： 从开花动态、传粉昆虫、花的形态结构、繁育系统、花粉活力和柱头可授性等方面研究了我国特有珍稀植物瘿椒树(Tapiscia sinensis Oliv.)的传粉生物学特性。瘿椒树是典型的雄全异株植物,两性花中含有功能性花粉,且自交亲和,但雄花花粉活力和萌发力是两性花的10倍以上。雄株和两性植株具有相同开花物候期,花期均为5月下旬至6月上旬,单花期为4-5天,雄花和两性花的5枚花药开裂的不同步性明显延长了散粉时间。两性花雌蕊先熟,柱头可授性较长。具有适应风媒和虫媒传粉的花部特征。传粉昆虫主要为蜜蜂科(Apidae)和食蚜蝇科(Syrphidae)昆虫,访花高峰期为8:30-10:30。维持瘿椒树雄全异株的可能机制是:雄株总体上增加了异交花粉的数量和质量;两性花的雄蕊为该物种提供了繁殖保障,同时为传粉者提供了报酬。

关键词： 构树   饲用价值   生态效益   开发利用  

摘要： 随着人口的不断增长，耕地数量的减少，粮食生产与饲料生成的矛盾日益严重。开发木本饲料资源，具有迫切的现实意义和深远的战略意义。构树是一种木本饲料，树叶富含高蛋白成分，是优质的畜禽饲料；果实富含氨基酸等有效成分，具有良好的药用和食用价值；另外，其纤维长，可作为造纸原料加以发展，同时也是绿化荒山、荒滩、防风固沙、水土保持的优良树种。本文主要综述了构树的生物学特性、饲用价值、生态效益、开发利用现状及展望。

关键词： F-box protein   Proteolysis   Male sterility   Phylogenetic tree  

摘要： F-box protein is an expanding family member of eukaryotic protein characterized by an F-box motif which has specificity of substrate recognition in the ubiquitin-mediated *** proteins have been proved to be critical for many physiological processes,such as cell-cycle transition,signal transduction,gene transcription,male sterility,programmed cell death （PCD） and so *** paper mainly introduces the biological functions of the known F-box proteins and the analysis of F-box gene phylogeny.

关键词： F-box蛋白   生物学功能   系统发育  

摘要： F-box蛋白是一类含有F-box结构域,在泛素介导的蛋白质水解过程中具有底物识别特性的蛋白质家族。这类蛋白质在细胞循环、信号传导、基因转录、雄性不育和细胞程序化死亡等多种生理过程中发挥重要作用。介绍了已知的植物F-box蛋白质的生物学功能并对F-box基因的系统进化进行了分析。

关键词： 红树   抗盐   耐重金属   分子生物学  

摘要： 红树林是热带和亚热带海岸潮间的木本植物群落,具有很强的抗逆特性。综述了红树植物抗逆分子生物学的研究进展,主要集中在红树植物对盐和重金属的抗性研究。目前,红树植物抗盐分子生物学研究已取得了显著的进展,其耐重金属分子生物学研究也有所突破。这些研究成果可以从分子水平为可持续利用红树林资源提供了更多的依据,对保护沿海及海洋生态系统具有重要的意义。

关键词： Woody weed   Aquatic weed   Legume   Biological control of weeds   Invasive plants  

摘要： Macaria pallidata (Warren) and Leuciris fimbriaria (Stoll) (Lepidoptera: Geometridae) are abundant and damaging defoliators of Mimosa pigra L. in the native range of the Neotropics. Both species were assessed for their suitability as biocontrol agents of M. pigra, a damaging invasive weed of northern Australia. Larvae feed on leaves of all ages. Adults are non-feeding, short-lived moths. Generation times are short and fecundity is high allowing rapid population increase. The host specificity of these species was tested using larval development tests on 70 test plant species. Development to adult of M. pallidata occurred on six species other than M. pigra. However, the survival rates were so low that these plants could not sustain a population of this insect species. The maximum survival rate was 1.1% compared to 64% on M. pigra. When the mean lifetime fecundity is considered, a survival rate of 1.1% is the minimum required for population maintenance in the absence of other mortality factors. Open-field trials in Mexico, although not comprehensive, support the conclusion that M. pallidata is specific to M. pigra. Development beyond first instar of L. fimbriaria did not occur on any species other than M. pigra and Mimosa asperata L. The number of eggs laid by M. pallidata was independent of plant phylogeny, but adults of L. fimbriaria laid more eggs on plants more closely related to M. pigra, indicating that not all Lepidoptera show indiscriminate oviposition choices in confined situations. Following the gaining of required permits, M. pallidata was released from 2002 and L. fimbriaria from 2004. Both have established. M. pallidata has been recovered in large numbers from most sites across areas of infestation of the invasive plant, but experiences extreme population fluctuations. L. fimbriaria has been found only at low levels. The rate of parasitism of M. pallidata was 5% with the tachinid fly Carcelia malayana Baranov being the most common parasite. (C) 2010 Elsevi

关键词： Studies   Animal behavior   Females   Mortality   Human influences   Males  

摘要： We studied the breeding biology of the Taiwan Barbet (Megalaima nuchalis) in the Taipei Botanical Garden (TBG) during the 2008 and 2009 breeding seasons. Breeding pairs produced a mean of 1.8 broods per season and had a mean clutch size of 3.0 eggs. The mean incubation period was 13.8 days, and both parents shared incubation. The mean nestling period was similar to 27.5 days, considerably shorter than that of other Asian barbets. The shorter nestling period may be related to the low fledgling success rate, multiple broods per season, and constant animal matter food in TBG throughout the entire nesting period. Ambient temperature influenced the amount of time spent by adults inside the nest cavity incubating eggs and brooding nestlings. Adult males provided more food to nestlings than adult females, while adult females cleaned the nest more often than males. The overall egg-to-fledgling success rate was low at 32.8%, because of infertile eggs and failure of eggs with embryos to hatch, abandonment, anthropogenic disturbances, predation, weather disturbances, and other unknown factors. Received 7 January 2010. Accepted 15 April 2010.

关键词： SYSTEMS biology   CIRCADIAN rhythms   PLANT growth   STRESS (Physiology)   BIOCHEMICAL genetics   PLANT hormones  

摘要： Whole-transcriptome analyses have established that the plant circadian clock regulates virtually every plant biological process and most prominently hormonal and stress response pathways. Systems biology efforts have successfully modeled the plant central clock machinery and an iterative process of model refinement and experimental validation has contributed significantly to the current view of the central clock machinery. The challenge now is to connect this central clock to the output pathways for understanding how the plant circadian clock contributes to plant growth and fitness in a changing environment. Undoubtedly, systems approaches will be needed to integrate and model the vastly increased volume of experimental data in order to extract meaningful biological information. Thus, we have entered an era of systems modeling, experimental testing, and refinement. This approach, coupled with advances from the genetic and biochemical analyses of clock function, is accelerating our progress towards a comprehensive understanding of the plant circadian clock network.

关键词： 国家自然科学基金委员会   植物激素   分子机制   NSFC   资助   中国   分子生物学   植物生物学  

摘要： Decades of physiological and molecular studies have demonstrated that plants rely on a diverse set of small molecule hormones to regulate every aspect of their biological processes including development,growth and adaptation.