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1.
Since times of Aristotle animals were considered as a group, opposing to plants. The last were distinguished by two characters. Plants as distinct from animals live the attached way of a life and all nutrients receive from a substratum on which live and from the surrounding air. Animals live an active way of life and exist due to digestion. Fungi at such definition belong to plants. Only in second half of XX centuries due to works of Whittaker and of Tachtadjan fungi have received the separate status equally with plants and animals. In this new system of a plant embraced either oxygenic phototrophs, or photosynthetic eukaryotes. The traditional characters distinguishing animals from plants and fungi are in detail analysed. Many of them appeared formal, not reflecting the structure of relationship. Comparing heterotrophs some authors saw in absorptive nutrition the main difference of fungi from animals. However on mechanisms of receipt of substances in a cell fungi, animals and plants do not differ. Phagocytosis and pinocytosis (clathrin-mediated endocytosis), considered as the most characteristic feature of animals, are revealed both in fungi, and in plants. On photosynthetic activity plants form heterogeneous group, differing on primary and secondary plastids. The last besides have the various origin connected to symbiogenesis of the host cell with red or green algae. Heterotrophy cannot be considered as a uniting attribute of fungi and animals. It is essentially different and focused on diverse food sources. Evolution of animals is connected to perfection of structure of a plasmatic membrane and saturation by its molecules allowing a cell, and through it all organism to be guided in an environment and adequally to be up to external irritants. At a cellular level animals use the various mechanisms of cellular activity connected to moving of cells, their combination in aggregates and complexes or, on the contrary, separation in new cellular configurations. The complex of cellular adaptations connected to the analysis of external signals and adequate response to them of cells, underlies the phenomenon of irritability. At a cellular level irritability is mediated through work of the actin apparatus. Lamarck in "Philosophie zoologique" considered irritability as the main distinctive feature of animals. Evolution of plants and fungi went in a direction of development of a secondary metabolism. The secondary metabolism, concerning synthesis of protective substances, is peculiar to all sedentary organisms, including the animals.  相似文献   

2.
SWEET蛋白家族研究进展   总被引:1,自引:0,他引:1  
SWEET是新发现的一类具有7次跨膜?-螺旋的糖运输蛋白,它们由2个重复的具有3次跨膜?-螺旋的MtN3 motif和一个起连接作用的跨膜?-螺旋组成.SWEET广泛存在于真核单细胞生物、高等植物以及动物中.它们在生殖发育、植物与微生物的相互作用、植物的逆境反应及衰老等许多方面起重要作用.最近的研究显示,原核生物中存在与真核生物SWEET类似的、只含有一个3次跨膜?-螺旋的蛋白,这些蛋白属于MtN3或PQ-Loop家族.从慢生根瘤菌中克隆的SWEET同源蛋白BjSemiSWEET1和已经鉴定的部分真核生物SWEET蛋白一样具有运输蔗糖的能力,这个结果与其他相关研究一起暗示真核生物7次跨膜?-螺旋的糖或氨基酸运输蛋白可能由原核生物中3次跨膜?-螺旋的小分子蛋白通过复制或横向基因转移融合进化而来,并且它们在行使功能时可能形成和其他许多膜转运蛋白相似的、具有12次跨膜结构的功能单位.对SWEET的研究将为揭示多种生命现象提供重要线索.  相似文献   

3.
In nature, essential resources for organisms, such as food for animals and light, water and nutrients for plants, are usually heterogeneously distributed, even at very small scale. As a result, all organisms, particularly plants mostly sessile, have a difficulty in acquiring essential resources from their environments. Animals express various types of foraging behavior to capture heterogeneously distributed essential foods. Clonal growth ( a vegetative reproductive process where by more than one individual of identical genetic composition is formed ) provides clonal plant not only with many "mouths" at different spatial positions, but also with a large spacial movability. As a clonal plant grows in environments characterized by a small-scale resource heterogeneity, its inter ramet connection permits a resource-sharing among the connected tamers. In addition, it may also allow certain ramets to respond locally and non-locally to resousce heterogeneity. This may lead to a division of labor among the connected ramets and a selective placement of ramets in favorable micro-habitats. Together these may enhance exploitation of resource heterogeneity by clonal plants, and in turn greatly contribute to maintenance or improvement of fitness. Such a behavior of clonal plants, expressed in heterogeneous environments, is to a large extent comparable to that of animals. Therefore, it has been considered as foraging behavior in clonal plants. More recently, it has been observed that phenotypic plasticity of clonal plants, which is relevant to foraging behavior, varies among species, types of genet architecture as well as among types of plants habitats. Foraging in clonal plants and its diversity have been receiving increasingly intensive investigations.  相似文献   

4.
The stable isotopic composition of water is routinely used as a tracer to study water exchange processes in vascular plants and ecosystems. To date, no study has focussed on isotope processes in non-vascular, poikilohydric organisms such as lichens and bryophytes. To understand basic isotope exchange processes of non-vascular plants, thallus water isotopic composition was studied in various green-algal lichens exposed to desiccation. The study indicates that lichens equilibrate with the isotopic composition of surrounding water vapour. A model was developed as a proof of concept that accounts for the specific water relations of these poikilohydric organisms. The approach incorporates first their variable thallus water potential and second a compartmentation of the thallus water into two isotopically distinct but connected water pools. Moreover, the results represent first steps towards the development of poikilohydric organisms as a recorder of ambient vapour isotopic composition.  相似文献   

5.
Bog ecosystems fulfil important functions in Earth's carbon and water turnover. While plant communities and their keystone species Sphagnum have been well studied, less is known about the microbial communities associated with them. To study our hypothesis that bog plants share an essential core of their microbiome despite their different phylogenetic origins, we analysed four plant community plots with 24 bryophytes, vascular plants and lichen species in two Alpine bogs in Austria by 16S rDNA amplicon sequencing followed by bioinformatic analyses. The overall bog microbiome was classified into 32 microbial phyla, while Proteobacteria (30.8%), Verrucomicrobia (20.3%) and Planctomycetes (15.1%) belonged to the most abundant groups. Interestingly, the archaeal phylum Euryarcheota represented 7.2% of total microbial abundance. However, a high portion of micro‐organisms remained unassigned at phylum and class level, respectively. The core microbiome of the bog vegetation contained 177 operational taxonomic units (OTUs) (150 526 seq.) and contributed to 49.5% of the total microbial abundance. Only a minor portion of associated core micro‐organisms was host specific for examined plant groups (5.9–11.6%). Using our new approach to analyse plant–microbial communities in an integral framework of ecosystem, vegetation and microbiome, we demonstrated that bog vegetation harboured a core microbiome that is shared between plants and lichens over the whole ecosystem and formed a transkingdom metacommunity. All micro‐ and macro‐organisms are connected to keystone Sphagnum mosses via set of microbial species, for example Burkholderia bryophila which was found associated with a wide spectrum of host plants and is known for a beneficial plant–microbe interaction.  相似文献   

6.
Soils are incredibly biodiverse habitats, yet soil-dwelling organisms have received little attention within the field of conservation biology. Due to difficulties involved in studying soil biota, and to taxonomic biases in conservation research, the full extent of soil biodiversity is not well understood, and soil-dwelling organisms are rarely candidates for conservation. The biogeography of soil biota differs significantly from that of plants or animals aboveground, and the taxonomic and functional diversity of soil-dwellers allows them to have a multitude of ecological effects on aboveground organisms. Soil organisms exhibit levels of biodiversity several orders of magnitude greater than those found in their aboveground counterparts on a per-area basis. The biodiversity of soils underpins many crucial ecosystem services which support the plants and animals typically targeted by conservation efforts. Strategies detailed in this paper provide practitioners with the ability to address many of the challenges related to incorporating soils and soil organisms into conservation planning.  相似文献   

7.
Students often prefer to study animals rather than plants, because they see plants as passive, less interesting organisms. This paper proposes a simple hands-on laboratory exercise for high-school students (grade 12) to arouse their interest in learning about plants and to demonstrate to them that plants are active organisms capable of defending themselves. In this classroom exercise, students investigate how a plant responds to an invader. As a model for study, the exercise uses three organisms: red chilli fruit, the yeast biological control agent Saccharomyces cerevisiae, and the pathogenic fungus Rhizopus stolonifer. Students gain basic knowledge about how plants defend themselves against pathogens by observing the physical changes of an infected wound site and by investigating the chemical compounds produced by plants in response to pathogen invasion; they are also encouraged to think critically about using biological control as a means to promote environmentally friendly agricultural practices.  相似文献   

8.
An individual of modular organisms, such as plants and fungi, consists of more than one module that is sometimes physically and physiologically connected with each other. We examined effects of translocation costs, resource–fitness relationships and original resource conditions for modules on the optimal resource translocation strategy for reproductive success in modular organisms with simple models. We considered two types of translocation cost: amount-dependent and ratio-dependent costs. Three optimal resource translocation strategies were recognized: all resource translocation (ART), partial resource translocation (PRT), and no resource translocation (NRT). These strategies depended on the translocation cost, shape of resource–fitness curve, and original resource condition for each module. Generally, a large translocation cost and a concave resource–fitness relationship promoted NRT or PRT. Meanwhile, a small translocation cost and convex resource–fitness relationship facilitated ART. The type of translocation cost did not strongly affect the optimal resource translocation patterns, although ART was never an optimal strategy when the cost was ratio-dependent. Resource translocation patterns found in modular plants were discussed in the light of our model results.  相似文献   

9.
The modularity of flowering plants is considered using well-substantiated module categories: elementary, universal, and basic. Their structural diversity, which is regarded as a result of heterochrony at the level of organs, their elements, and whole organisms is shown. The heterochrony is considered to be a process of changes in the ontomorphogenesis of individuals, structural elements, and their parts in flowering plants; some of them are realized as heterotopies.  相似文献   

10.
Mahonia×lindsayae P.F. Yeo ‘Cantab’ is illustrated, and its history is revealed. This continues a series of articles on plants connected with the Botanic Garden of Cambridge University – plants either raised there or distributed from there over the past 100 years or so. As with many of the others, this present plant has a complex history, involving accidental notice of seedlings and inferences about parentage; the original living plants have mostly disappeared, but descendants of some of them are still growing.  相似文献   

11.
Pairs of nutsedge plants connected by rhizomes were planted, each in a separate pan, without cutting the rhizomes. One plant within each pair was treated with 5.7 kg of dicamba per hectare seven days later. Ten days after treatment, the treated plants and those plants attached to them by rhizomes were harvested separately and analyzed by gas chromatography. The attached plants were found to contain 6 per cent as much dicamba as did the directly treated plants. The suspected metabolites, 3,6-dicblorosalicylic acid, 3,6-dicblorogentisic acid and 5-HO-dicamba, were not detected.  相似文献   

12.
Microbial activity in the rhizosphere can have positive and negative effects on plants. Some of the beneficial processes act by minimizing the negative effects or by modifying the cropping environment to enhance productivity. Processes that are considered here include the provision of nitrogen, phosphorus and iron to the plant, the biocontrol of diseases and deleterious organisms and the stabilization of soil structures. The use of genetic engineering techniques in studying these processes and generating novel strains which may enhance them is discussed, along with the possible consequences of the release of organisms into the environment.  相似文献   

13.
Saponins occur constitutively in many plant species as part of their defense system. However, saponin content in plants seems to be dynamic, responding to many external factors including various biotic stimuli connected to herbivory attack and pathogenic infection, as well as involved in plant mutualistic symbioses with rhizobial bacteria and mycorrhizal fungi. Thus, not only saponins influence the living organisms interacting with plants, but in turn, all these interactions can impact the plant saponin content. According to their constitutive occurrence in plants, saponins are regarded mainly as phytoanticipins. Nevertheless, some presented data clearly point out to induced biosynthesis of saponins, especially in plant response to insect herbivory or inoculation with root symbionts, while the best studied examples of interactions between plants and their microbial pathogens show rather qualitative change of saponin composition based on chemical modifications of preformed, pre-infectional precursors. Simultaneously, despite evident inducibility of saponin production in plant cell cultures, the possible role of these compounds as phytoalexins synthesized in intact plants after pathogen infection is still not well documented. Some practical patterns and ecological consequences of biotic factors influencing saponin content in plants are briefly highlighted, with the special attention paid to microbial inoculants applied for optimisation of saponin synthesis in cultivated medicinal plants.  相似文献   

14.
Wayne R  Staves MP 《Bioscience》1996,46(5):365-369
The Krogh principle refers to the use of a large number of animals to study the large number of physiological problems, rather than limiting study to a particular organism for all problems. There may be organisms that are more suited to study of a particular problem than others. This same principle applies to plants. The authors are concerned with the recent trend in plant biology of using Arabidopsis thaliana as the "organism of choice." Arabidopsis is an excellent organism for molecular genetic research, but other plants are superior models for other research areas of plant biology. The authors present examples of the successful use of the Krogh principle in plant cell biology research, emphasizing the particular characteristics of the selected research organisms that make them the appropriate choice.  相似文献   

15.
Protein domains characteristic of eukaryotic innate immunity and apoptosis have many prokaryotic counterparts of unknown function. By reconstructing interactomes computationally, we found that bacterial proteins containing these domains are part of a network that also includes other domains not hitherto associated with immunity. This network is connected to the network of prokaryotic signal transduction proteins, such as histidine kinases and chemoreceptors. The network varies considerably in domain composition and degree of paralogy, even between strains of the same species, and its repetitive domains are often amplified recently, with individual repeats sharing up to 100% sequence identity. Both phenomena are evidence of considerable evolutionary pressure and thus compatible with a role in the “arms race” between host and pathogen. In order to investigate the relationship of this network to its eukaryotic counterparts, we performed a cluster analysis of organisms based on a census of its constituent domains across all fully sequenced genomes. We obtained a large central cluster of mainly unicellular organisms, from which multicellular organisms radiate out in two main directions. One is taken by multicellular bacteria, primarily cyanobacteria and actinomycetes, and plants form an extension of this direction, connected via the basal, unicellular cyanobacteria. The second main direction is taken by animals and fungi, which form separate branches with a common root in the α-proteobacteria of the central cluster. This analysis supports the notion that the innate immunity networks of eukaryotes originated from their endosymbionts and that increases in the complexity of these networks accompanied the emergence of multicellularity.  相似文献   

16.
The photosynthetic, autotrophic lifestyle of plants and algae position them as ideal platform organisms for sustainable production of biomolecules. However, their use in industrial biotechnology is limited in comparison to heterotrophic organisms, such as bacteria and yeast. This usage gap is in part due to the challenges in generating genetically modified plants and algae and in part due to the difficulty in the development of synthetic biology tools for manipulating gene expression in these systems. Plant and algal metabolism, pre-installed with multiple biosynthetic modules for precursor compounds, bypasses the requirement to install these pathways in conventional production organisms, and creates new opportunities for the industrial production of complex molecules. This review provides a broad overview of the successes, challenges and future prospects for genetic engineering in plants and algae for enhanced or de novo production of biomolecules. The toolbox of technologies and strategies that have been used to engineer metabolism are discussed, and the potential use of engineered plants for industrial manufacturing of large quantities of high-value compounds is explored. This review also discusses the routes that have been taken to modify the profiles of primary metabolites for increasing the nutritional quality of foods as well as the production of specialized metabolites, cosmetics, pharmaceuticals and industrial chemicals. As the universe of high-value biosynthetic pathways continues to expand, and the tools to engineer these pathways continue to develop, it is likely plants and algae will become increasingly valuable for the biomanufacturing of high-value compounds.  相似文献   

17.
Amoeboid organisms are phylogenetically diverse, some being more closely related to plants or metazoans than to each other. Amoeboid organisms are ecologically successful, having been isolated on all continents, including Antarctica, as well as being the main predators controlling bacterial populations in soil. The classification of these organisms has historically relied upon morphological characteristics. The application of electron microscopy, comparison of enzymic profiles after electrophoretic separation, and analysis of nucleic acid fractions have provided reliable bases for classifying amoeboid organisms. The extent of diversity of these organisms has been recognized, as methods to detect, culture, characterize and identify them has increased. It is reasonable to anticipate that the current 40 000 species of protists will increase substantially as amoeboid organisms are cultivated from poorly accessible niches and from extreme environs.  相似文献   

18.
Green leaf volatiles: hydroperoxide lyase pathway of oxylipin metabolism   总被引:5,自引:0,他引:5  
Green leaf volatiles (GLVs) are C(6) aldehydes, alcohols, and their esters formed through the hydroperoxide lyase pathway of oxylipin metabolism. Plants start to form GLVs after disruption of their tissues and after suffering biotic or abiotic stresses. GLV formation is thought to be regulated at the step of lipid-hydrolysis, which provides free fatty acids to the pathway. Recently, studies dissecting the physiological significance of GLVs in plants have emerged, and it has been postulated that GLVs are important molecules both for signaling within and between plants and for allowing plants and other organisms surrounding them to recognize or compete with each other.  相似文献   

19.
A systematic screening of 170 different West Bengal plants was carried out to find antifungal antibiotics, usingAspergillus niger andTrichophyton rubrum as test organisms. From them, four plant species, viz.Curcuma zedoaria, C. aromatica, C. amada, and aBrassica sp. have been found to contain active antibiotic principles with strong inhibitory effects against both test organisms.  相似文献   

20.
水环境中微囊藻毒素的生物降解   总被引:9,自引:0,他引:9  
微囊藻毒素在水环境中的生物降解是决定其环境归趋和影响其毒性的重要因素。本文综述了水细菌、鱼类、水生植物、水生无脊椎动物、浮游动物等水生生物对微囊藻毒素生物降解方面的研究进展。目前报道的微囊藻毒素降解菌有鞘氨醇单胞菌、铜绿假单胞菌和青枯菌。鞘氨醇单胞菌和铜绿假单胞菌分别以微囊藻毒素酶和碱性蛋白酶降解毒素,青枯菌降解机理未明;而鱼类、水生植物、水生无脊椎动物、浮游动物等水生生物主要通过谷胱甘肽S-转移酶催化形成低毒性的微囊藻毒素-谷胱甘肽结合物进行转化。本文还对水环境微囊藻毒素的生物修复方式进行了初步的探讨。  相似文献   

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