韧皮部取食昆虫诱导的植物防御反应

刺吸式昆虫与寄主植物之间具有特殊的生物互作关系。本文对刺吸式昆虫取食韧皮部诱导的植物防御反应类型、 防御物质变化、 信号途径以及植物反应转录组学研究等方面进行综述。韧皮部取食昆虫取食诱导的植物防御反应机制主要包括： (1)改变自身的营养状况; (2)产生有毒的次生化合物; (3)产生防御蛋白。防御反应与植物水杨酸、 茉莉酸、 乙烯等信号分子密切相关。研究表明, 刺吸式昆虫取食诱导的植物防御反应主要引发以水杨酸为主的信号途径, 但相关分子互作机制还有待明确。日益丰富的基因组资源和不断发展的分子生物学技术为揭示植物防御反应中信号分子的作用机制、 找出植物内生抗性的特异因子以及阐明诱导防御机制奠定了基础。了解刺吸式昆虫取食诱导的植物防御反应, 为深入理解植物-昆虫间协同进化关系提供了依据, 为害虫治理和抗虫植物的培育提供了新的思路。     

虫害诱导植物间接防御反应的激发与信号转导途径

植物通过产生和释放挥发性物质增加植食性昆虫的天敌对其寄主或猎物的定位,减少植食性昆虫对植物的取食,从而达到间接防御的目的。植物对植食性昆虫所做出间接防御反应激发因子和信号转导途径的研究,对应用虫害诱导植物挥发物引诱害虫天敌,并进一步从植物、植食性昆虫及其天敌间三级营养关系,研究动植物协同进化机理和病虫害防治具有深远意义。本文根据国内外最新研究进展,对虫害诱导植物间接防御反应的激发因子,昆虫取食信号的转导途径及对植物间接防御相关基因的激活等方面进行了系统地综述。     

植食性昆虫适应植物防御反应的研究进展

在植物与植食性昆虫协同进化过程中,植物在不断完善其防御反应,同时植食性昆虫也在选择压下不断适应植物防御反应。植食性昆虫适应植物防御反应存在多样性。昆虫能够利用其唾液中的效应因子抑制或弱化植物防御反应,激活其肠道中的某些特异性蛋白阻断植物防御性次生代谢物的产生或者将其直接降解,以及通过其携带微生物间接抑制植物防御反应。此外,昆虫还能够通过产卵、虫害诱导植物挥发物、识别植物防御物质等方式适应植物的防御反应。本文综述了植食性昆虫如何利用各种效应因子适应寄主植物防御反应的研究进展。     

昆虫对植物抗虫性的诱导

植物的抗虫性主要表现为受遗传因素控制的遗传抗性和受环境因素控制的生态抗性两个方面。植物的抗性主要由遗传因素决定,但其抗性表达和抗虫幅度又受到环境因子的影响。环境因子可改变植物的生理状态和理化性质,使植物不合适作为某种昆虫的寄主,从而提高了植物的抗性水平。植食性昆虫对植物抗虫性的诱导是环境影响抗性表达的一个重要方面,它是植物对取食者的一种重要的防御策略,同时也是植物与植食者协同进化的结果,进一步了解和充分发挥诱导抗性的作用,对抗虫有种工作和害虫的综合治理都有指导意义。三植食性昆虫对植物抗虫性的诱导…     

植物与植食性昆虫防御与反防御的三个层次

在植物与植食性昆虫长期的进化过程中,双方形成了一系列的防御与反防御策略。本文将这些策略归为3个层次:第一层次起始于植物对植食性昆虫相关分子模式的识别,并由此激活植食性昆虫分子模式相关的免疫反应。这种免疫反应对于不能产生效应子的植食性昆虫种群是有效的;第二层次是一些植食性昆虫种群可以通过释放特异性效应子抑制植物产生的植食性昆虫分子模式相关的免疫反应,从而在植物上正常生长与繁衍;第三层次是一些植物基因型可以通过特异抗性基因识别植食性昆虫的效应子,进而激活效应子诱导的免疫反应,表现出特异的抗虫性。深入揭示植物与植食性昆虫间的这种分子互作机制,不仅在理论上有助于理解昆虫与植物的协同进化机制,而且在实践上可为作物抗性品种的培育提供重要的技术指导。     

模拟昆虫取食对牛膝菊防御特征的影响

为了解入侵植物牛膝菊的入侵机理,研究其应对昆虫取食的响应,在开花前喷洒不同浓度(5、10、20 mmol·L-1)的茉莉酸甲酯(MeJA)来模拟不同程度的昆虫取食,试验结束时测定其株高、叶片数、花序数、生物量、比叶面积、叶上表皮毛密度,以及叶和花序中的缩合单宁、总酚、黄酮含量.结果表明:5 mmol·L-1 MeJA处...     

植食性昆虫诱导的挥发物及其在植物通讯中的作用

正常健康植株的挥发物代谢维持在基底水平,当遭到昆虫取食时,植物释放出特定的挥发物,用来招引害虫的天敌,还能诱导邻近植株产生防御反应.文章就此问题的研究进展作了介绍.     

植物对昆虫的化学防御

植物对昆虫的化学防御康乐（中国科学院动物研究所,北京１０００８０）ＴＨＥＣＨＥＭＩＣＡＬＤＥＦＥＮＳＥＳＯＦＦＰＬＡＮＴＳＴＯＰＨＹＴＯＰＨＡＧＯＵＳＩＮＳＥＣＴＳＫａｎｇＬｅ（ＩｎｓｌｉｔｒｔｅｏｆＺｏｏｌｏｇｙ,ＡｃａｄｅｍｉａＳｉｎｉｃａＢｅｉ...     

植物地上部与地下部的诱导防御反应研究综述

地球上大多数植物对病虫害的侵袭具有诱导防御反应。植物地上部与地下部之间存在着密切的生理生态关系,因此,地上部处理是否影响地下部的防御反应以及地下部处理是否影响地上部的防御反应,进而分别影响到地下部和地上部生物的行为成为当前研究的热点。本文系统地综述了地上部机械损伤、害虫取食、信号物质处理对植物地下部防御反应及生物行为影响以及地下部机械损伤、害虫取食、信号物质处理对植物地上部防御反应及生物行为影响的研究进展,并在此基础上提出了未来该领域值得进一步研究的方向,以期为深入研究植物地上部与地下部诱导防御间的相互关系提供科学依据。     

植物竞争和昆虫取食调节入侵植物对土壤细菌群落和功能的影响

以入侵植物空心莲子草(Alternanthera philoxeroides(Mart.)Griseb)、本土近缘种莲子草(Alternan-thera sessilis(L.)DC)、生防昆虫莲草直胸跳甲(Agasicles hygrophila(Selman&Vogt))和本地昆虫虾钳菜披龟甲(Cassida pi...     

Mechanisms of plant defense against insect herbivores

Plants respond to herbivory through various morphological, biochemicals, and molecular mechanisms to counter/offset the effects of herbivore attack. The biochemical mechanisms of defense against the herbivores are wide-ranging, highly dynamic, and are mediated both by direct and indirect defenses. The defensive compounds are either produced constitutively or in response to plant damage, and affect feeding, growth, and survival of herbivores. In addition, plants also release volatile organic compounds that attract the natural enemies of the herbivores. These strategies either act independently or in conjunction with each other. However, our understanding of these defensive mechanisms is still limited. Induced resistance could be exploited as an important tool for the pest management to minimize the amounts of insecticides used for pest control. Host plant resistance to insects, particularly, induced resistance, can also be manipulated with the use of chemical elicitors of secondary metabolites, which confer resistance to insects. By understanding the mechanisms of induced resistance, we can predict the herbivores that are likely to be affected by induced responses. The elicitors of induced responses can be sprayed on crop plants to build up the natural defense system against damage caused by herbivores. The induced responses can also be engineered genetically, so that the defensive compounds are constitutively produced in plants against are challenged by the herbivory. Induced resistance can be exploited for developing crop cultivars, which readily produce the inducible response upon mild infestation, and can act as one of components of integrated pest management for sustainable crop production.     

Herbivore induced plant volatiles: Their role in plant defense for pest management

Plants respond to herbivory through different defensive mechanisms. The induction of volatile emission is one of the important and immediate response of plants to herbivory. Herbivore-induced plant volatiles (HIPVs) are involved in plant communication with natural enemies of the insect herbivores, neighboring plants, and different parts of the damaged plant. Release of a wide variety of HIPVs in response to herbivore damage and their role in plant-plant, plant-carnivore and intraplant communications represents a new facet of the complex interactions among different trophic levels. HIPVs are released from leaves, flowers, and fruits into the atmosphere or into the soil from roots in response to herbivore attack. Moreover, HIPVs act as feeding and/or oviposition deterrents to insect pests. HIPVs also mediate the interactions between the plants and the microorganisms. This review presents an overview of HIPVs emitted by plants, their role in plant defense against herbivores and their implications for pest management.     

Latitudinal patterns in plant defense: evolution of cardenolides, their toxicity and induction following herbivory

Attempts over the past 50 years to explain variation in the abundance, distribution and diversity of plant secondary compounds gave rise to theories of plant defense. Remarkably, few phylogenetically robust tests of these long-standing theories have been conducted. Using >50 species of milkweed (Asclepias spp.), we show that variation among plant species in the induction of toxic cardenolides is explained by latitude, with higher inducibility evolving more frequently at lower latitudes. We also found that: (1) the production of cardenolides showed positive-correlated evolution with the diversity of cardenolides, (2) greater cardenolide investment by a species is accompanied by an increase in an estimate of toxicity (measured as chemical polarity) and (3) instead of trading off, constitutive and induced cardenolides were positively correlated. Analyses of root and shoot cardenolides showed concordant patterns. Thus, milkweed species from lower latitudes are better defended with higher inducibility, greater diversity and added toxicity of cardenolides.     

Innovation in anti-herbivore defense systems during neopolypoloidy - the functional consequences of instantaneous speciation

Allopolyploid hybridization instantly merges two differentially adapted genomes into one individual. Allopolyploids are often evolutionarily successful, undergoing adaptive radiations despite the genetic and physiological challenges of merging genomes. We examine a suite of induced herbivore resistance traits in three independent lines of the synthetic allopolyploid Nicotianaxmierata (Nma) and its parent species, N. miersii (Nmi) and N. attenuata (Na), to determine how a complex polygenetic adaptation fares during the early stages of neoallopolyploid formation. All species responded to Manduca sexta oral secretions (OS) with a temporally prolonged jasmonate (JA) burst. In one parent (Na), the JA burst was additionally amplified and associated with the elicitation of direct and indirect defenses. In the other parent (Nmi), OS neither amplified the JA burst nor elicited defense responses, although applied MeJA confirmed the inducibility of the defense responses. All lines of Nma retained enough aspects of Na's JA signaling to recognize OS and to accumulate sufficient direct defenses to impair the growth of Manduca larvae. Most defense-related metabolites were retained in Nma even if inherited from only one parent; however, OS-elicited volatiles, trypsin protease inhibitors (TPIs) and chlorogenic acid were lost in some lines, even though MeJA treatment elicited similar responses in all lines. Herbivore defense systems are flexibly inherited in allopolyploids, causing individuals to diverge over only a few generations; for example, line 1 of Nma could not produce TPIs after OS elicitation, whereas lines 2 and 3 could. This flexible integration of defense signaling systems with a diversity of elicited responses may explain why adaptive radiations are commonly found in allopolyploid lineages.     

Future directions in the study of induced plant responses to herbivory

This paper reviews current progress and makes recommendations for future studies of induced plant responses to herbivory in three research areas: the role of induction in structuring herbivore communities, costs associated with the expression of induced responses, and theory and data on the macro‐evolution of induced responses. It is argued that although mechanistic approaches will be important for progress, it is also critical to maintain a holistic approach, including a consideration of field environments, multi‐species interactions, and patterns over ecological and evolutionary time.     

植物和刺吸式口器昆虫的诱导防御与反防御研究进展

刺吸式口器昆虫在长期的进化过程中形成特殊的口针结构,用于专门吸食植物韧皮部筛管细胞的汁液成分.以蚜虫为例,它们在取食过程中分泌的胶状唾液和水状唾液将有效的降低植物防御反应,其中水状唾液包含的大量酶类不仅可以帮助蚜虫穿刺植物韧皮部,刺探到筛管细胞,同时也是植物感受蚜虫为害的激发因子,诱导出植物防御反应和相关抗性基因的表达...     

Optimal defense strategy against herbivory in plants: Conditions selecting for induced defense, constitutive defense, and no-defense

To examine the conditions selecting for induced defense, constitutive defense, and no-defense, we developed a model of plant defense strategy against herbivory. In the model, a plant consists of two modules between which signal inducing defense compounds can be translocated. We assume three strategies: plants produce defense compounds responding to herbivory (induced defense), they have the compounds beforehand (constitutive defense), and they never produce the compounds (no-defense). We found that no-defense is optimal if the amount of biomass lost due to herbivory is small because of the growth cost of having defense compounds. The constitutive defense is optimal if the amount of biomass lost is not so small and the probability of herbivory is high. If the biomass loss is not so small but the probability of herbivory is low, the induced defense or no-defense is optimal. When the induced defense is optimal, the probability of herbivory necessarily increases in plants once herbivory has occurred. If the probability stays the same, no-defense is optimal. Thus, the behavior of herbivores, i.e., whether they remain around a plant and attack it repeatedly, affects the evolution of the induced defense.     

Indirect plant defense against insect herbivores: a review

Plants respond to herbivore attack by launching 2 types of defenses: direct defense and indirect defense. Direct defense includes all plant traits that increase the resistance of host plants to insect herbivores by affecting the physiology and/or behavior of the attackers. Indirect defense includes all traits that by themselves do not have significant direct impact on the attacking herbivores, but can attract natural enemies of the herbivores and thus reduce plant loss. When plants recognize herbivore‐associated elicitors, they produce and release a blend of volatiles that can attract predators, parasites, and other natural enemies. Known herbivore‐associated elicitors include fatty acid–amino acid conjugates, sulfur‐containing fatty acids, fragments of cell walls, peptides, esters, and enzymes. Identified plant volatiles include terpenes, nitrogenous compounds, and indoles. In addition, constitive traits including extrafloral nectars, food bodies, and domatia can be further induced to higher levels and attract natural enemies as well as provide food and shelter to carnivores. A better understanding of indirect plant defense at global and componential levels via advanced high throughput technologies may lead to utilization of indirect defense in suppression of herbivore damage to plants.