共查询到20条相似文献，搜索用时 23 毫秒
1.
Plants interact with the environment by sensing "non-self" molecules called elicitors derived from pathogens or other sources. These molecules bind to specific receptors located in the plasma membrane and trigger defense responses leading to protection against pathogens. In particular, it has been shown that cell wall and storage polysaccharides from green, brown and red seaweeds (marine macroalgae) corresponding to ulvans, alginates, fucans, laminarin and carrageenans can trigger defense responses in plants enhancing protection against pathogens. In addition, oligosaccharides obtained by depolymerization of seaweed polysaccharides also induce protection against viral, fungal and bacterial infections in plants. In particular, most seaweed polysaccharides and derived oligosaccharides trigger an initial oxidative burst at local level and the activation of salicylic (SA), jasmonic acid (JA) and/or ethylene signaling pathways at systemic level. The activation of these signaling pathways leads to an increased expression of genes encoding: (i) Pathogenesis-Related (PR) proteins with antifungal and antibacterial activities; (ii) defense enzymes such as pheylalanine ammonia lyase (PAL) and lipoxygenase (LOX) which determine accumulation of phenylpropanoid compounds (PPCs) and oxylipins with antiviral, antifugal and antibacterial activities and iii) enzymes involved in synthesis of terpenes, terpenoids and/or alkaloids having antimicrobial activities. Thus, seaweed polysaccharides and their derived oligosaccharides induced the accumulation of proteins and compounds with antimicrobial activities that determine, at least in part, the enhanced protection against pathogens in plants. 相似文献
2.
Deepak Nanjappa Giuliana d’Ippolito Carmela Gallo Adriana Zingone Angelo Fontana 《Marine drugs》2014,12(1):368-384
Marine planktonic organisms, such as diatoms, are prospective sources of novel bioactive metabolites. Oxygenated derivatives of fatty acids, generally referred to as oxylipins, in diatoms comprise a highly diverse and complex family of secondary metabolites. These molecules have recently been implicated in several biological processes including intra- and inter-cellular signaling as well as in defense against biotic stressors and grazers. Here, we analyze the production and diversity of C20 and C22 non-volatile oxylipins in five species of the family Leptocylindraceae, which constitute a basal clade in the diatom phylogeny. We report the presence of species-specific lipoxygenase activity and oxylipin patterns, providing the first demonstration of enzymatic production of docosahexaenoic acid derivatives in marine diatoms. The differences observed in lipoxygenase pathways among the species investigated broadly reflected the relationships observed with phylogenetic markers, thus providing functional support to the taxonomic diversity of the individual species. 相似文献
3.
Polyunsaturated aldehydes (PUA) are supposed to play critical roles in chemically-mediated plankton interactions. Laboratory studies suggest that they act as mediators of chemical defense and chemical communication. PUA are oxylipins containing an α,β,γ,δ-unsaturated aldehyde structure element and are mainly found in diatoms. We present here a detailed surface mapping of PUA during a spring bloom of the diatom Skeletonema marinoi in the Adriatic Sea. We monitored dissolved PUA, as well as particulate PUA, which are produced by phytoplankton after cell disintegration. Our survey revealed a patchy distribution of PUA and shows that at most stations S. marinoi is the major contributor to the overall PUA. Our data also suggest that lysis of a diatom bloom can contribute significantly to the dissolved PUA concentrations and that other producers, which are smaller in cell size compared to diatoms, have to be taken into account as well if the total PUA content of marine samples is considered. The analyses of samples collected in deeper water suggests that diatom contribution to PUA decreases with depth, while smaller-sized unidentified organisms take place as dominant contributors to the PUA concentrations. 相似文献
4.
Alessandra Mirtes Marques Neves Gon?alves Aline Brito de Lima Maria Cristina da Silva Barbosa Luiz Fernando de Camargos Júlia Teixeira de Oliveira Camila de Souza Barbosa José Augusto Ferreira Perez Villar André Carvalho Costa Isabella Viana Gomes da Silva Luciana Maria Silva Fernando de Pilla Varotti Fabio Vieira dos Santos Gustavo Henrique Ribeiro Viana 《Marine drugs》2014,12(8):4361-4378
Cancer continues to be one of the most important health problems worldwide, and the identification of novel drugs and treatments to address this disease is urgent. During recent years, marine organisms have proven to be a promising source of new compounds with action against tumoral cell lines. Here, we describe the synthesis and anticancer activity of eight new 3-alkylpyridine alkaloid (3-APA) analogs in four steps and with good yields. The key step for the synthesis of these compounds is a Williamson etherification under phase-transfer conditions. We investigated the influence of the length of the alkyl chain attached to position 3 of the pyridine ring on the cytotoxicity of these compounds. Biological assays demonstrated that compounds with an alkyl chain of ten carbon atoms (4c and 5c) were the most active against two tumoral cell lines: RKO-AS-45-1 and HeLa. Micronucleus and TUNEL assays showed that both compounds are mutagenic and induce apoptosis. In addition, Compound 5c altered the cellular actin cytoskeleton in RKO-AS-45-1 cells. The results suggest that Compounds 4c and 5c may be novel prototype anticancer agents. 相似文献
5.
G. Obolensky 《Plant foods for human nutrition (Dordrecht, Netherlands)》1958,5(1-2):45-63
Summary In view of the increased importance, which Vanilla consumption is taking in the food industry to-day, an increase of the Vanillin percentage in Vanilla pods, by means of Ultra-Sonic treatments, was tried.It was therefore of particular interest to develop a new method which could increase the Vanillin and Oleoresins percentage, as treatments with X-rays, Ultra-violett, Infrat-red, yperite etc. did not give the expected results.In our previous publications we have shown that enzymes can be activated by Ultra-Sonic treatments (see alpha-amylase and cellulase), and as on the other hand the formation of Vanillin and Oleoresins are due to biochemical (enzymatic) processes, it was logical to try to induce an increase of these constituents by means of this new method.Our hypothesis has proved to be right and after several years of intensive research, we were able to prove that Ultra-Sonics of certain specific frequencies and intensities, are able to induce an increase of 25–35% of Vanillin and 10–15% of the Oleoresins in the treated Vanilla pods. 相似文献
6.
Ion channels are tightly involved in various aspects of cell physiology, including cell signaling, proliferation, motility, endo- and exo-cytosis. They may be involved in toxin production and release by marine dinoflagellates, as well as harmful algal bloom proliferation. So far, the patch-clamp technique, which is the most powerful method to study the activity of ion channels, has not been applied to dinoflagellate cells, due to their complex cellulose-containing cell coverings. In this paper, we describe a new approach to overcome this problem, based on the preparation of spheroplasts from armored bloom-forming dinoflagellate Prorocentrum minimum. We treated the cells of P. minimum with a cellulose synthesis inhibitor, 2,6-dichlorobenzonitrile (DCB), and found out that it could also induce ecdysis and arrest cell shape maintenance in these microalgae. Treatment with 100–250 µM DCB led to an acceptable 10% yield of P. minimum spheroplasts and was independent of the incubation time in the range of 1–5 days. We show that such spheroplasts are suitable for patch-clamping in the cell-attached mode and can form 1–10 GOhm patch contact with a glass micropipette, allowing recording of ion channel activity. The first single-channel recordings of dinoflagellate ion channels are presented. 相似文献
7.
Noel M. Lacerna II Cydee Marie V. Ramones Jose Miguel D. Robes Myra Ruth D. Picart Jortan O. Tun Bailey W. Miller Margo G. Haygood Eric W. Schmidt Lilibeth A. Salvador-Reyes Gisela P. Concepcion 《Marine drugs》2020,18(12)
The bioactivity-guided purification of the culture broth of the shipworm endosymbiont Teredinibacter turnerae strain 991H.S.0a.06 yielded a new fatty acid, turneroic acid (1), and two previously described oxylipins (2–3). Turneroic acid (1) is an 18-carbon fatty acid decorated by a hydroxy group and an epoxide ring. Compounds 1–3 inhibited bacterial biofilm formation in Staphylococcus epidermidis, while only 3 showed antimicrobial activity against planktonic S. epidermidis. Comparison of the bioactivity of 1–3 with structurally related compounds indicated the importance of the epoxide moiety for selective and potent biofilm inhibition. 相似文献
8.
小麦阶段性冻害的生理机制及预防途径研究进展 总被引：7，自引：1，他引：6
为系统了解小麦抗寒性研究现状,从遗传、生理、栽培、遥感等方面对小麦阶段性冻害发生的生理机制及预防途径的研究进展进行了总结和评述。小麦抗寒性受多个微效基因控制,低温锻炼激发这些基因,诱导冻蛋白或冷激蛋白的合成和功能表达;低温补偿系统、植株营养以及水分代谢的失衡是小麦冻害发生的主要生理原因;通过品种选择、适当晚播、提高播种质量、合理施肥、生物化学调控可提高小麦抗寒性,减少冻害发生和危害;利用遥感监测可对小麦冻害做出快速有效的评估。 相似文献
9.
10.
Fernando Dures Nikoletta Szemerdi Decha Kumla Madalena Pinto Anake Kijjoa Gabriella Spengler Emília Sousa 《Marine drugs》2021,19(9)
Marine-derived fungi constitute an interesting source of bioactive compounds, several of which exhibit antibacterial activity. These acquire special importance, considering that antimicrobial resistance is becoming more widespread. The overexpression of efflux pumps, capable of expelling antimicrobials out of bacterial cells, is one of the most worrisome mechanisms. There has been an ongoing effort to find not only new antimicrobials, but also compounds that can block resistance mechanisms which can be used in combination with approved antimicrobial drugs. In this work, a library of nineteen marine natural products, isolated from marine-derived fungi of the genera Neosartorya and Aspergillus, was evaluated for their potential as bacterial efflux pump inhibitors as well as the antimicrobial-related mechanisms, such as inhibition of biofilm formation and quorum-sensing. Docking studies were performed to predict their efflux pump action. These compounds were also tested for their cytotoxicity in mouse fibroblast cell line NIH/3T3. The results obtained suggest that the marine-derived fungal metabolites are a promising source of compounds with potential to revert antimicrobial resistance and serve as an inspiration for the synthesis of new antimicrobial drugs. 相似文献
11.
《Field Crops Research》2006,98(1):76-81
The Livingstone potato (Plectranthus esculentus N.E.Br.) produces a cluster of edible tubers at the base of the stem that are used as a potato substitute in many areas of Africa. No information is available on factors affecting tuberization in this species. Photoperiod is known to influence storage organ formation in a wide range of crops, and pilot trials indicated that it also played a role in tuberization in P. esculentus. The critical photoperiod for tuber induction, as well as the number of short-day cycles required to induce tubers, were investigated in glasshouse trials using in vitro plants. Nine photoperiod treatments (30-min intervals from 10 to 14 h of light) were applied in the critical photoperiod experiment. To determine the number of short-day cycles required to induce tuberization, plants were exposed to short days (10 h light) for periods ranging from 0 to 20 days at 2-day intervals. Data were collected from both intact plants and sub-apical two-node cuttings made after the experimental treatments were completed. The critical photoperiod for the specific genotype used in this study was between 12.5 and 13 h, with cuttings giving a slightly exaggerated result over that of intact plants. It was established that exposure to four short-day cycles was sufficient to induce tuberization in this species. 相似文献
12.
13.
萜烯类化合物是植物中重要的次生代谢产物之一,对茶树挥发性香气的组成起着重要作用。从茶树基因组数据库中鉴定获得了141个茶树萜烯类合成相关基因,并对其不同组织表达特异性进行分析,筛选出16个在茶树顶芽和嫩叶中高表达的萜烯类合成代表基因。生物信息学分析结果表明,系统进化关系将茶树与拟南芥和葡萄的萜烯类合成相关基因分成了4个亚家族;茶树萜烯类合成相关基因含有5~14个外显子,在上游启动子区域分析发现了大量与光响应、植物生长发育、激素和胁迫响应密切相关的顺式作用元件。荧光定量检测发现,CsMVK、CsDXS和CsGGPS在白茶萎凋过程中的表达显著上调;CsDXR、CsMCT、CsCMK、CsMCS、CsHDS、CsGPPS和CsGGPPS在萎凋4 h和24 h的表达达到峰值。本研究结果为进一步挖掘茶叶萎凋过程中萜烯类合成相关基因对茶叶香气组分积累提供了理论依据。 相似文献
14.
Cyanobacteria produce metabolites with diverse bioactivities, structures and pharmacological properties. The effects of microcystins (MCYs), a family of peptide type protein-phosphatase inhibitors and cylindrospermopsin (CYN), an alkaloid type of protein synthesis blocker will be discussed in this review. We are focusing mainly on cyanotoxin-induced changes of chromatin organization and their possible cellular mechanisms. The particularities of plant cells explain the importance of such studies. Preprophase bands (PPBs) are premitotic cytoskeletal structures important in the determination of plant cell division plane. Phragmoplasts are cytoskeletal structures involved in plant cytokinesis. Both cyanotoxins induce the formation of multipolar spindles and disrupted phragmoplasts, leading to abnormal sister chromatid segregation during mitosis. Thus, MCY and CYN are probably inducing alterations of chromosome number. MCY induces programmed cell death: chromatin condensation, nucleus fragmentation, necrosis, alterations of nuclease and protease enzyme activities and patterns. The above effects may be related to elevated reactive oxygen species (ROS) and/or disfunctioning of microtubule associated proteins. Specific effects: MCY-LR induces histone H3 hyperphosphorylation leading to incomplete chromatid segregation and the formation of micronuclei. CYN induces the formation of split or double PPB directly related to protein synthesis inhibition. Cyanotoxins are powerful tools in the study of plant cell organization. 相似文献
15.
An ideal surface for implantable glucose sensors would be able to evade the events leading to chronic inflammation and fibrosis, thereby extending its utility in an in vivo environment. Nafion?, a perfluorinated ionomer, is the membrane material preferred for in situ glucose sensors. Unfortunately, the surface properties of Nafion? promote random protein adsorption and eventual foreign body encapsulation, thus leading to loss of glucose signal over time. Details of the techniques to render Nafion? nonprotein fouling are given in a previous article [T. I. Valdes et al., Biomaterials 29, 1356 (2008)]. Once random protein adsorption is prevented, a biologically active peptide can be covalently bonded to the treated Nafion? to induce cellular adhesion. Cellular responses to these novel decorated Nafion? surfaces are detailed here, including cell viability, cell spreading, and type I collagen synthesis. Normal human dermal fibroblasts (NHDFs) were cultured on control and modified Nafion? surfaces. Findings indicate that Nafion? modified with 10% 2-hydroxyethyl methacrylate and 90% tetraglyme created a nonfouling surface that was subsequently decorated with the YRGDS peptide. NHDFs were shown to have exhibited decreased type I collagen production in comparison to NHDF cells on unmodified Nafion? surfaces. Here, the authors report evidence that proves that optimizing conditions to prevent protein adsorption and enhance cellular adhesion may eliminate fibrous encapsulation of an implant. 相似文献
16.
Carotenoids are a class of diverse pigments with important biological roles such as light capture and antioxidative activities. Many novel carotenoids have been isolated from marine organisms to date and have shown various utilizations as nutraceuticals and pharmaceuticals. In this review, we summarize the pathways and enzymes of carotenoid synthesis and discuss various modifications of marine carotenoids. The advances in metabolic engineering and synthetic biology for carotenoid production are also reviewed, in hopes that this review will promote the exploration of marine carotenoid for their utilizations. 相似文献
17.
Animals use olfaction to detect developmentally significant volatile organic compounds (VOCs) in their local environment. As part of a wider study aiming to demonstrate that the olfactory responses of animals to VOCs can be modified through the creation of a drug-addicted status and association with a selected VOC, we investigated nicotine and tobacco smoke particulate (TSP) extract as possible addictive compounds for male German cockroaches, Blattella germanica (Linnaeus). In feeding experiments using an artificial food stimulus, food treated with TSP extract was preferred over untreated food. Surprisingly, nicotine, which was expected to be the most important addictive tobacco component, did not induce noticeable effects on cockroach behavior. Both TSP extract and nicotine were shown to be phagostimulants. Olfactometry assays that measured odor-mediated insect behavior demonstrated that male B. germanica did not choose TSP-extract-treated food even when attempts were made specifically to train them via this modality. These results support a hypothesis that B. germanica needs to consume TSP-containing food to show a clear preference for this stimulus and that gustatory mechanisms are involved due to compounds present in the TSP extract. 相似文献
18.
With the growing demand for comfortable, clean and hygienic textile goods, an urgent need for production of antimicrobial textiles has arisen. In this work, synthesis of nano titanium oxide has been done by sol gel method and the effect of dispersing agents with varying ionic character during synthesis on the particle size of the synthesised nano particles in terms of crystallinity and particle size was studied. It was observed that cationic as well as non-ionic dispersing agents led to reduction in size of the titania particles produced whereas anionic dispersing agent led to increase in the particle size. This method provides a simple method for reduction in size of titanium dioxide particles with a minor modification of a standard process. The synthesized nano titanium dioxide particles were successfully applied onto cotton to obtain Antimicrobial activity. The Durability of the antimicrobial activity was upto 10 washes with the help of Binder. The effect of the application of nano titanium oxide on the physical properties of the substrate, such as tensile strength, bending length, and crease recovery angle has been analysed. 相似文献
19.
Deyong Zeng Jie Cui Yishu Yin Meng Zhang Shan Shan Xin Gao Yingchun Zhang Yeqing Sun Weihong Lu 《水稻科学》2020,27(5):423-433
As a unique form of abiotic stress, the environmental conditions of outer space are expected to induce changes in plant genomes, proteomes and metabolic pathways. However, the effect of outer space conditions on the overall physiology of plants at the protein level has yet to be reported. To investigate the effects of outer space conditions on the growth- and development-related physiological processes and metabolic pathways of rice different stages, the seeds of rice variety DN423 were sent into orbit for 12.5 d aboard the SJ-10 Returning Satellite, and then the seedlings of both treated and control rice were compared at the three-leaf stage (TLS) and tillering stage (TS). In addition to comparing plant growth and reactive oxygen species (ROS) levels, seedling proteomes were also compared using isobaric tags for relative and absolute quantitation (iTRAQ). Space flight increased TLS plant height by 20%, reduced and increased ROS levels of the TLS and TS seedlings, respectively, and affected the expression of 36 and 323 proteins in TLS and TS leaves, respectively. Furthermore, the functions of the differentially abundant proteins were mainly associated with metabolism, energy, and protein synthesis and degradation. These results suggested that the exposure of seeds to outer space conditions affects the subsequent abundance of key signaling proteins, gene expression, and the processes of protein synthesis and degradation, thereby affecting metabolic processes and promoting adaptation to the abiotic stress of outer space. As such, the present study sheds light on the effects of space flight on plants and contributes to a more comprehensive understanding of extraterrestrial biology. 相似文献
20.
In this paper, fuzzy logic method was used to model the effect of stain repellent treatment on plush knitted fabrics intended for baby clothes. In order to reduce the complexity of the models and increase the knowledge and comprehension of the underlying process, a fuzzy sensitivity variation criterion was used to select the most relevant parameters which are taken as inputs of the reduced fuzzy logic models. The outputs are the water-oil contact angles characterizing the stain repellent behavior of fabrics and the percentage of decrease of air permeability to control the change of hygienic comfort. Obtained results showed that the hydrophilic samples were transformed to water-oil repellent ones and some experimental conditions induce a high contact angle without affecting the air permeability. 相似文献