褐藻胶寡糖制备的研究进展

褐藻胶寡糖(alginate oligosaccharides,AOS)是褐藻胶降解而形成的一种功能性寡糖,具有广泛的生物活性,如促进植物生长、提高植物抗逆性、抗氧化、抗菌、抗肿瘤等。褐藻胶寡糖的制备方法主要分为:化学法、物理法和酶解法。不同的方法制备出的褐藻胶寡糖结构亦有所不同。介绍了化学法、物理法和酶解法等各种褐藻胶寡糖制备方法的研究现状、存在的问题及发展趋势。     

植物细胞壁寡糖素的生理功能

植物细胞壁可分泌各种寡糖信息分子,称为寡糖素。它们对植物的抗性、生长速度、形态发生等方面有一定的调控作用。说明细胞壁是一个具有广泛生理活性的构造。     

真菌寡糖诱导植物抗性活性成分的分离纯化

寡聚糖作为一种信号分子 ,在调节植物的生长、发育以及植物在不同环境中生存能力等方面起着非常重要的作用[1] .许多特定结构的寡糖被证明具有诱导植物抗性的作用 .对具有诱导抗性作用的葡聚寡糖结构分析表明 ,其最小活性寡糖单位是由 7个葡葡糖残基组成的 β 葡聚糖苷 ,在一个     

寡糖素对红花及三七培养细胞的生理作用

三种寡糖素,即来自人参（Ｐａｎａｘ ｇｉｎｓｅｎｇ）培养细胞的人参寡糖素、红花（Ｃａｒｔｈａｍｕｓ ｔｉｎｃｔｏｒｉｕｓ）培养细胞的红花寡糖素、黑节草（Ｄｅｎｄｒｏｂｉｕｍ ｃａｎｄｉｄｕｍ）植物的黑节草寡糖素对红花及三七（Ｐａｎａｘ ｎｏｔｏｇｉｎｓｅｎｇ）的培养细胞的生长及代谢产物的含量均有显著的促进作用。寡糖素可耐高温高压（１２１℃、．ｂｓ／ｃｍ＾２）灭菌１５分钟而不失活,其对植物培养细胞的     

生物技术制备植物性来源的功能寡糖

功能性寡糖是近年来国内外竞相开发的热点之一 ,其中植物性来源的多聚糖经生物技术处理制备的功能寡糖以其原料来源广泛、安全及较好的生理功能而倍受青睐。本文简要介绍了国内外寡糖产品的开发研究现状和发展趋势 ,着重介绍了两个由植物半纤维素类原料制备的功能寡糖———木寡糖、半乳甘露寡糖的研究进展     

壳寡糖对烟草花叶病毒的体外钝化作用

壳寡糖是一种由脱乙酰基几丁质经酶降解后制备的氨基葡萄糖,它具有多方面的生物活性,在调节植物的生理机能、调控植物形态发生、诱导植物抗病性、抗逆性以及抑制真菌、细菌的生长发育等方面的作用多有报道,但关于壳寡糖对植物病毒的抑制作用未见报道.     

褐藻胶寡糖对毒死蜱胁迫下小麦幼苗生理生化指标的影响

褐藻胶寡糖对植物的生长发育具有调控作用。为了探讨褐藻胶寡糖对植物抗逆性的作用,以青丰Ⅰ号小麦种子为试验材料,探究了不同浓度褐藻胶寡糖(0、0.05%、0.1%、0.2%、0.4%)对毒死蜱胁迫下小麦生理特性的缓解作用。结果表明:毒死蜱显著降低小麦幼苗中叶绿素a、叶绿素b及总叶绿素含量(P0.05),使脯氨酸、可溶性蛋白及可溶性糖含量显著升高(P0.05),生物量降低,抑制地上部分生物量积累,根冠比增加;褐藻胶寡糖对这些生理生化指标的变化起到显著的缓解作用(P0.05);浓度为0.4%的褐藻胶寡糖缓解作用最为显著(P0.01)。因此,褐藻胶寡糖使毒死蜱对小麦幼苗的伤害有明显缓解作用,增强植物对毒死蜱胁迫的抗性。     

种子中的棉子糖半乳糖苷系列寡糖研究进展

棉子糖半乳糖苷系列寡糖广泛分布在许多种植物种子中,并存在于干燥后仍能保持活力的组织内,如禾谷类种子的胚及糊粉层,豆类及其他双子叶植物的子叶和胚轴组织等。棉子糖半乳糖苷系列寡糖在禾谷类种子的非自溶性中央胚乳中不合成,但存在于蓖麻种子的自溶性胚乳细胞中。棉子糖半乳糖苷系列寡糖在种子发育后期累积,并持续到种子大量成熟直到脱水阶段。棉子糖半乳糖苷系列寡糖主要包括棉子糖、水苏糖和毛蕊花糖,是种子中最广泛的低分子量α_半乳糖苷。许多植物正常性种子的发育伴随着棉子糖半乳糖苷系列寡糖的累积,这些糖的累积已被认为在种子脱水耐性获得、种子活力、糖的运输及植物的抗冷驯化等过程 中起重要作用。本文从种子的脱水耐性获得、植物的冷驯化、细胞内定位及生物合成等方面综述了棉子糖半乳糖苷系列寡糖的研究进展。     

壳寡糖对辣椒种子萌发及幼苗抗氧化酶活性影响研究

壳寡糖是甲壳素的重要衍生物,具有良好的生物学活性,可调节植物生长,使农作物和水果蔬菜增产丰收,因而在农业上的应用日渐增多,在农业上的应用,包括促进种子萌发和植物生长。本文选取辣椒种子为研究对象,探讨了不同浓度壳寡糖对辣椒种子萌发的影响,研究结果表明一定浓度的壳寡糖可以促进种子萌发,以0.10mg/L浓度的壳寡糖效果最显著;不同浓度壳寡糖浸种处理能激活辣椒幼苗抗氧化酶活性。     

黄原胶寡糖生物活性的研究

利用黄原胶降解菌Cellulom onassp.XT11生产的黄原胶降解酶,对黄原胶进行生物降解,生产具有不同粘度/还原末端比的黄原胶寡糖,并研究了黄原胶寡糖在清除羟基自由基、植物防卫反应中激活因子活性和对植物病原菌抑制能力等方面的生物活性,结果表明黄原胶寡糖具有清除羟基自由基能力,并能激活植物防卫系统以抵御病原菌的侵染,同时对野油菜黄单孢菌也具有抑菌活性。     

诱导子促进植物次生代谢产物生产的研究进展

本文简要介绍了诱导子的分类和应用概况,讨论了诱导子的筛选、作用机制、作用效果等研究热点问题,同时简要介绍了诱导子之间的互作关系以及诱导子对植物生理生化反应的影响。     

The Problems of Specific Phytoimmunity

Recent studies established that the specificity of phytoimmunity is shaped at the initial stages of genic interactions between a pathogen and its plant host. While elicitors, the products of pathogen avirulence genes (avr-genes), have been already investigated in great detail, there are few studies on the products of plant resistance genes (R-genes) recognizing these elicitors. This review deals with examples of nonspecific and specific elicitors of some R-genes as well as the systems that transduce the elicited signals to the plant genome and evoke immune responses in the plant cells. Several types of immunosuppressors characteristic of pathogens are considered. The molecular-genetic studies of the relations between the pathogens and their plant hosts supplement the already existing arsenal for plant protection with new technologies, such as the genetically engineered plant resistance and the resistance induced by biogenic elicitors.     

植食性昆虫唾液效应子和激发子的研究进展

植食性昆虫与寄主植物通过协同进化形成了复杂的防御和反防御机制.本文系统综述了昆虫唾液效应子和激发子在植物与昆虫互作中的作用及机理.昆虫取食中释放的唾液激发子被植物识别而激活植物早期免疫反应,昆虫也能从口腔分泌效应子到植物体内抑制免疫;抗性植物则利用抗性(R)蛋白识别昆虫无毒效应子,启动效应子诱导的免疫反应,而昆虫又进化...     

Effect of various phytoimmunocorrectors on fruit and soft fruit cultures

Catalase activity and induction of delayed chlorophyll fluorescence were shown to be the markers of plant native state. The dependence of reaction of the plant to exogenous elicitors, stimulators or inhibitors of defense system, on the age, cultivar and/or species was found. Prolonged effect of the treatment with phytoimmunocorrectors was observed. The necessity of careful choice of elicitors depending on the plant state was shown.     

Effects of Various Phytoimmunocorrectors on Fruit and Soft Fruit Cultures

Catalase activity and induction of delayed chlorophyll fluorescence were shown to be the markers of the plant native state. The dependence of reaction of the plant to exogenous elicitors, stimulators or inhibitors of the defense system, on the age, cultivar and/or species was found. Prolonged effect of the treatment with phytoimmunocorrectors was observed. The necessity of careful choice of elicitors depending on the plant state was shown.     

Effects of elicitors of host plant defenses on pear psylla,Cacopsylla pyricola

Pear psylla, Cacopsylla pyricola (Foerster) (Hemiptera: Psyllidae), is a key pest of cultivated pear [Pyrus communis L. (Rosaceae)] in North America and Europe. We examined the effects of foliar applications of three commercially available chemical elicitors of host‐plant defenses — Actigard (acibenzolar‐S‐methyl), Employ (harpin protein), and ODC (chitosan) — on survival, development, feeding, and egg laying of C. pyricola. All three defense elicitors reduced the number of nymphs present on pear (cvs. Bartlett or D'Anjou) 30 days after releasing 10 adults on the trees. Choice assays showed that females settled and oviposited on untreated trees more often than on trees treated with any of the three defense elicitors. Results of no‐choice assays confirmed that the effects of Actigard, Employ, and ODC on C. pyricola were due to activation of systemic plant responses that led to reduced oviposition preference and nymph survival. However, results did not provide evidence that plant responses to elicitors led to reduced nymphal feeding rates or development. Results of our laboratory studies suggest that commercial defense elicitors may be useful in the integrated management of pear psylla once the effects of elicitors at an ecological scale are better understood.     

The case for the defense: plants versus Pseudomonas syringae

Incredible progress has been made over the last 20 years in understanding the components and mechanisms governing plant innate immunity. The most important discoveries concern pathogen recognition mechanisms, which divide perception of conserved elicitors at the cell periphery, and recognition of variable elicitors within the host cytoplasm. The underlying mechanisms of immunity post elicitation are complex and poorly defined. This review highlights emergent themes in plant–microbe interactions with a particular focus on the plant immune responses against infection by the bacterium Pseudomonas syringae.     

刺激剂(elicitor)在植物细胞培养次生代谢物生产中的应用

刺激剂（ｅｌｉｃｉｔｏｒ）在植物细胞培养中被用来作为提高次生代谢物产量的手段。文中概括介绍了微生物、寡聚糖、蛋白质、第二信使及其他物质作为刺激剂在植物细胞培养中的应用及其研究成果。     

Cell surfaces in plant-microorganism interactions. VII. Elicitor preparations from two fungal pathogens depolarize plant membranes

Fungal elicitors, obtained from the mycelium of two plant pathogens, depolarized the plasmalemma of plant roots by reducing the electrogenic component of the membrane potential. The effect was rapid, stable, reversible and unrelated to pathogen specificity. These results are in agreement with the hypothesis that elicitors act at the cell surface level.     

Perception, signaling and molecular basis of oviposition-mediated plant responses

Eggs deposited on plants by herbivorous insects represent a threat as they develop into feeding larvae. Plants are not a passive substrate and have evolved sophisticated mechanisms to detect eggs and induce direct and indirect defenses. Recent years have seen exciting development in molecular aspects of egg-induced responses. Some egg-associated elicitors have been identified, and signaling pathways and egg-induced expression profiles are being uncovered. Depending on the mode of oviposition, both the jasmonic acid and salicylic acid pathways seem to play a role in the induction of defense responses. An emerging concept is that eggs are recognized like microbial pathogens and innate immune responses are triggered. In addition, some eggs contain elicitors that induce highly specific defenses in plants. Examples of egg-induced suppression of defense or, on the contrary, egg-induced resistance highlight the complexity of plant–egg interactions in an on-going arms race between herbivores and their hosts. A major challenge is to identify plant receptors for egg-associated elicitors, to assess the specificity of these elicitors and to identify molecular components that underlie various responses to oviposition.